Wastegate okay, now what?
11-01-2004, 11:41 AM
#16
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Special tool - what's your problem anyway? Did you not read Claus' post above? The repair I made is identical to what he did (which worked BTW). Rennlist is supposed to be a forum where people can share information and knowledge to help others out. I may be fairly new to the world of the 951 (I've only had this car about two months and I've driven it less than 200 miles), but I fail to see what the hell did I do to you to deserve your kind of juvenile name-calling B.S. Are you just insecure that someone so "inexperienced" in their 951 ownership might have actually figured out a problem and (*gasp* God-forbid!) come up with a remedy that doesn't involve throwing piles of money at the car? OH THE HORROR! You must think of me as an "unworthy" Porsche owner since I didn't spend at least $200 on this repair or something. 
Honestly, and you think I'M acting 17!
You obviously didn't read ANY of the history of what I've gone through with this car, you know NOTHING about who I am and it's frankly absolutely irrelevant to this discussion. FWIW, your assumptions are completely wrong about me; I enjoyed quite a good laugh at your public display of ignorance at that one. If you can't contribute in an adult fashion, do us all a favor and bug off and go troll on some other board.
I seriously doubt you've seen a CV for $40 (I'm guessing that's what you meant by "fort" in your articulate and well-worded post above) unless you're perhaps delusional, drunk, coked up, or otherwise living in a fantasy world. Maybe you're off your meds again. Who knows. Anyway, I looked on a number of distributors' web sites and made a few phone calls on this subject, so I think I've done my homework on this subject and probably know a little more than you do at this point. FWIW the cheapest I've seen is roughly $100 and that's from Lindsey Racing; the dealership wants nearly double that. If you'd bothered to read the above, you'd note that I do have a replacement CV being sent courtesy of NZ951, but it's coming from New Zealand and as such, it might take a little while to get here. Unlike you, he's actually DOING something to help out that's relevant to the discussion and in the spirit of the forum instead of coming in here and acting like a pompous know-it-all jackass that puts down anybody that doesn't accept throwing piles of money at their cars as an acceptable remedy to a very simple problem.
My objective here is to get the car running properly so I can tune it and drive it temporarily until a proper fix can be made when my parts to do it arrive. I'd kind of like to get this car out of my garage in the meantime (I have a few things that need to be done on my 944 as well so I need the "repair bay" freed up). As such, the repair needs to be good enough to last two weeks or however long it takes for the replacement CV to get here from "down under". Since the same repair described above lasted "for years", I think it'll probably suffice.
Here's what I did (again) - spelled out step-by-step using very small words that even someone like yourself can understand.
(1) I verified that 3/16" vaccum connectors would fit snugly into the orfices on the cycling valve. These are the small plastic things with "barbs" or "scallops" on them to help them hold snugly. They fit perfectly into the orifices on the CV.
(2) I took HIGH TEMPERATURE silicone - the copper-based stuff, since that's what I happen to have around and "painted" or "smeared" a thin ring of the stuff around the scalloped end of the vaccum connector that was to be inserted into the orfices on the CV. I did not glom the stuff in there so that it would plug up the orfice - honestly, I'm truly offended that you'd think someone would be so stupid as to do that. The purpose of it was to fill in the grooves between the high points of the "ribs" or "scallops" so there's no blow-by and it makes an air-tight seal, even under pressure or vaccum. Think of it as creating a series of small "O-rings" along the shaft of the vaccum connector. The silicone actually isn't necessary to hold the vaccum connectors in. As stated above (if you'd bothered to read it), the connectors fit snugly inside on their own.
(3) I re-inserted the silicone-painted vaccum connector back into the appropriate "hole" on the CV and used a wire to "clean out" the tube down the center of the vaccum connector and ultimately into the interior of the CV. In no case was there any silicone even there (it had stayed where I wanted it to - on the outside). This was a precautionary step only.
(4) I blew into the new nipple thus created to check for proper and unobstructed flow. In all cases, it worked fine.
(5) After a few hours, I connected rubber hose to the new CV nipples and used a hand vaccum pump to apply vaccum pressure to test for leakage past the vaccum connectors I'd installed. The repairs held 25 psi of vaccum perfectly.
(6) Reconnection, reassembly, and testing. When I left off last night, I just had to hook up the intercooler pipes and air box. I'll do that tonight and test it.
I'm pretty certain this will end up fixing the problem.
Bengt Sweden, thanks for your input. The problem I had before is kind of what you're alluding to - the wastegate hose was open to the atmosphere (not connected to the CV, since the nipple on the CV was snapped off). As such, there was nothing preventing air from rushing in to the volume of space created on top of the WG diaphragm when the valve tried to move down. As such, the only thing opposing the action of the exhaust gas pressure was the spring tension and why it was opening at 1.2 bar worth of pressure - it's supposed to, according to what I've read on Clark's Garage.
The connections at the J-boot (the small line that goes to the CV via the metal pipe under the intake) are fine. I'm pretty certain the closed state of the CV ducting higher pressure air from the turbo outlet pipe (via the banjo bolt) to the CV to the J-boot will function fine. I'll check it using my hand pump before testing though by applying vaccum to the end of the skinny hose that plugs into the J-boot and feeling for suction at the banjo bolt.
The purpose of posting this long tale is to maybe, hopefully provide some insight into the turbo system and potential problems that can develop in it and solutions to them. This (as I see it) is the purpose of Rennlist and its real value. It's a shame that some people don't see that and simply use it as an excuse to try and (unsuccessfully) elevate themselves to the "alpha male" monkey in the pack. If anybody takes away information from this thread that they didn't have before and learns something, I've done my job. It's just sad certain others don't see it that way, contribute nothing, and lower the overall value of the forums.
Honestly, and you think I'M acting 17!You obviously didn't read ANY of the history of what I've gone through with this car, you know NOTHING about who I am and it's frankly absolutely irrelevant to this discussion. FWIW, your assumptions are completely wrong about me; I enjoyed quite a good laugh at your public display of ignorance at that one. If you can't contribute in an adult fashion, do us all a favor and bug off and go troll on some other board.
I seriously doubt you've seen a CV for $40 (I'm guessing that's what you meant by "fort" in your articulate and well-worded post above) unless you're perhaps delusional, drunk, coked up, or otherwise living in a fantasy world. Maybe you're off your meds again. Who knows. Anyway, I looked on a number of distributors' web sites and made a few phone calls on this subject, so I think I've done my homework on this subject and probably know a little more than you do at this point. FWIW the cheapest I've seen is roughly $100 and that's from Lindsey Racing; the dealership wants nearly double that. If you'd bothered to read the above, you'd note that I do have a replacement CV being sent courtesy of NZ951, but it's coming from New Zealand and as such, it might take a little while to get here. Unlike you, he's actually DOING something to help out that's relevant to the discussion and in the spirit of the forum instead of coming in here and acting like a pompous know-it-all jackass that puts down anybody that doesn't accept throwing piles of money at their cars as an acceptable remedy to a very simple problem.
My objective here is to get the car running properly so I can tune it and drive it temporarily until a proper fix can be made when my parts to do it arrive. I'd kind of like to get this car out of my garage in the meantime (I have a few things that need to be done on my 944 as well so I need the "repair bay" freed up). As such, the repair needs to be good enough to last two weeks or however long it takes for the replacement CV to get here from "down under". Since the same repair described above lasted "for years", I think it'll probably suffice.
Here's what I did (again) - spelled out step-by-step using very small words that even someone like yourself can understand.
(1) I verified that 3/16" vaccum connectors would fit snugly into the orfices on the cycling valve. These are the small plastic things with "barbs" or "scallops" on them to help them hold snugly. They fit perfectly into the orifices on the CV.
(2) I took HIGH TEMPERATURE silicone - the copper-based stuff, since that's what I happen to have around and "painted" or "smeared" a thin ring of the stuff around the scalloped end of the vaccum connector that was to be inserted into the orfices on the CV. I did not glom the stuff in there so that it would plug up the orfice - honestly, I'm truly offended that you'd think someone would be so stupid as to do that. The purpose of it was to fill in the grooves between the high points of the "ribs" or "scallops" so there's no blow-by and it makes an air-tight seal, even under pressure or vaccum. Think of it as creating a series of small "O-rings" along the shaft of the vaccum connector. The silicone actually isn't necessary to hold the vaccum connectors in. As stated above (if you'd bothered to read it), the connectors fit snugly inside on their own.
(3) I re-inserted the silicone-painted vaccum connector back into the appropriate "hole" on the CV and used a wire to "clean out" the tube down the center of the vaccum connector and ultimately into the interior of the CV. In no case was there any silicone even there (it had stayed where I wanted it to - on the outside). This was a precautionary step only.
(4) I blew into the new nipple thus created to check for proper and unobstructed flow. In all cases, it worked fine.
(5) After a few hours, I connected rubber hose to the new CV nipples and used a hand vaccum pump to apply vaccum pressure to test for leakage past the vaccum connectors I'd installed. The repairs held 25 psi of vaccum perfectly.
(6) Reconnection, reassembly, and testing. When I left off last night, I just had to hook up the intercooler pipes and air box. I'll do that tonight and test it.
I'm pretty certain this will end up fixing the problem.
Bengt Sweden, thanks for your input. The problem I had before is kind of what you're alluding to - the wastegate hose was open to the atmosphere (not connected to the CV, since the nipple on the CV was snapped off). As such, there was nothing preventing air from rushing in to the volume of space created on top of the WG diaphragm when the valve tried to move down. As such, the only thing opposing the action of the exhaust gas pressure was the spring tension and why it was opening at 1.2 bar worth of pressure - it's supposed to, according to what I've read on Clark's Garage.
The connections at the J-boot (the small line that goes to the CV via the metal pipe under the intake) are fine. I'm pretty certain the closed state of the CV ducting higher pressure air from the turbo outlet pipe (via the banjo bolt) to the CV to the J-boot will function fine. I'll check it using my hand pump before testing though by applying vaccum to the end of the skinny hose that plugs into the J-boot and feeling for suction at the banjo bolt.
The purpose of posting this long tale is to maybe, hopefully provide some insight into the turbo system and potential problems that can develop in it and solutions to them. This (as I see it) is the purpose of Rennlist and its real value. It's a shame that some people don't see that and simply use it as an excuse to try and (unsuccessfully) elevate themselves to the "alpha male" monkey in the pack. If anybody takes away information from this thread that they didn't have before and learns something, I've done my job. It's just sad certain others don't see it that way, contribute nothing, and lower the overall value of the forums.
11-01-2004, 11:46 AM
#17
Originally Posted by special tool
Dude - take that silicon and throw it in the river. SILICON??? And you have it all over the j-tube also?
Your cv jury rig is NOT going to fix anything. You will still have no boost. You have to put everything back to factory first at least.
And saying that Someone has to know? When you have glue stuffed in your intercooler-idle stabilizer???? Over the internet, no less. You HAVE to be 17 years old.
There is no magic miracle in the cv holding the wastegate closed - it is a very simple solenoid that the klr throws open when it thinks (not closed loop) the correct boost pressure should be there.
You are quikly approaching Hosrom gogo status, sport. Get a new cv for fort bucks, and fix everything correctly and stop fvcking around!!!!
Some of you kids over complicat the hell out of these cars. Don't. They are simple. Don't go reading Sport compact car about WOTM's Supra and think you stock 951 is ANYTHING like it.
-cranky this morning, no coffee yet
Your cv jury rig is NOT going to fix anything. You will still have no boost. You have to put everything back to factory first at least.
And saying that Someone has to know? When you have glue stuffed in your intercooler-idle stabilizer???? Over the internet, no less. You HAVE to be 17 years old.
There is no magic miracle in the cv holding the wastegate closed - it is a very simple solenoid that the klr throws open when it thinks (not closed loop) the correct boost pressure should be there.
You are quikly approaching Hosrom gogo status, sport. Get a new cv for fort bucks, and fix everything correctly and stop fvcking around!!!!
Some of you kids over complicat the hell out of these cars. Don't. They are simple. Don't go reading Sport compact car about WOTM's Supra and think you stock 951 is ANYTHING like it.
-cranky this morning, no coffee yet
11-01-2004, 02:00 PM
#21
Race Director
"As such, my suspicion is that the only thing opposing the building boost pressure was the wastegate spring (no vaccum on top of the diaphragm) so at 1.2 bar, the valve opened and whoosh - out the boost goes down the tailpipe."
Jeff, you're correct and this is exactly the way the wastegate is supposed to operate. The ONLY thing that ever closes the stock wastegate valve is the spring-tension. The test you did with the air-compressor on the wastegate diaphragm is correct, however the precision of the gauge isn't good enough. What you should've seen is that the valve barely creeps open at 2-3psi and is fully open (15mm) by about 8-10psi. Shimming the stock wastegate will have it start to open at 4-5psi and fully open by 10-12.
"SOMEONE out there has to know the answer to this - what allows the wastegate to stay closed and build up pressure beyond the 1.2 bar limit provided by the wastegate spring? Is it the drop in pressure created above the diaphragm as the valve tries to move downwards and open or what?"
No, it's the CV that diverts pressure away from the wastegate and allows the spring to stay closed more. Ok, here's a quick synopsis on how the stock boost-control system works... I think you're getting boost-pressure (intake-manifold) mixed up with exhaust-pressure (headers & crossover).
The wastegate diaphragm is opened by boost-pressure coming from the intercooler pipe. There is a regulation valve in between, the CV-cycling valve. In the unpowered, passive OFF state, it lets through all pressure from the intercooler-pipe to the wastegate, as if the CV wasn't even there at all:
This is a failsafe default mode that's designed for safety. If something happens to the KLR or the CV fails, the system lets through ALL boost to the wastegate. The resulting boost is the effective spring-rate in the wastegate. As mentioned before, it starts to open at 2-3psi above atmospheric.
Since the bottom of wastegate diaphragm is vented to atmosphere, the pressure pushing down on the diaphram has to be about 2-3psi above atm, or 1.2-1.3 bar. Note that in the intercooler pipe, pressure is always atmospheric or above. Vacuum only exists in the intake-manifold after the restriction caused by the throttle-body. You might get a little bit of vacuum in the intercooler when you initially increase throttle under partial-throttle cruising, but not much. So effectively, pressure in the intercooler-pipe is atmospheric or above. So in the default unpowered state, the CV lets through all pressure and the most boost you'll get is 1.2 bar on the dash gauge.
Then the KLR computer turns on & off the CV with a duty-cycle curve like an injector as Gator_86_951 drew above. This causes the CV to divert pressure AWAY from the wastegate and back to the intake J-boot. This reduced pressure going to the wastegate allows the valve to stay closed more and build up boost:
Note the three vector directions. The ONLY thing closing the wastegate valve is the spring-tension. Opposing that is the pressure in the diaphragm and exhaust-pressure. Exhaust-pressure is NOT the same as boost-pressure. It goes up as a straight function of boost & RPM, while boost-pressure is managed by the boost-controller and turbo's compressor map. It's the sum of diaphragm pressure and exhaust pressure that acts on the wastegate spring:
Not that in the upper-RPMs, exhaust-pressure alone is all that's needed to open the wastegate valve. I've measured pressure of 10-50psi in the crossover under normal operations. Shimming the wastegate increases the spring-preload and helps it resist exhaust-pressure:
Note that pressure going to the wastegate's diaphragm (blue) is a direct in->out function of the mechanical boost-controller. As boost hits a certain level to open the check-valve, a certain pressure makes it past to the diaphragm. However, it doesn't take into account exhaust-pressures, and in the upper-RPMs, a mechanical boost-controller let's through too much pressure, thus opening the wastegate early and dumping boost. To get a flat-boost curve, you need something that can measure exhaust-pressure. An electronic boost-controller can do that through fuzzy logic inference:
It can through recording previous runs, figure out the dropping boost (learns exhaust-pressure indirectly). Thus in the upper-RPMs, even at the same 15psi boost, an EBC will slowly bleed off pressure going to the wastegate, thus keeping it closed tighter and tighter as exhaust-pressure increases.
As you guys can figure out by now, leaks in the boost-control hoses would leak out pressure that's sent to open the wastegate. The effects of leaks is to increase boost. In the early days, people actually purposely introduce leaks to increase boost, like drilling holes in the CyclingValve or using aquarium bleeder valves on the hoses. This has the effect off linearly increasing the boost-curve upwards.
So Jeff, you've done your testing correctly. Regardless of whether or not you plug up the nipple on the wastegate or clamp the line going to it, if you keep all pressure away from the diaphragm, you'll keep the wastegate fully closed. Just by unplugging the hose, you can expect to see 30psi+ from a stock turbo (ask me how I know) If you're not getting that, there's something wrong other than your boost-control system, don't waste your time fixing hoses and leaks going to the wastegate.
Jeff, you're correct and this is exactly the way the wastegate is supposed to operate. The ONLY thing that ever closes the stock wastegate valve is the spring-tension. The test you did with the air-compressor on the wastegate diaphragm is correct, however the precision of the gauge isn't good enough. What you should've seen is that the valve barely creeps open at 2-3psi and is fully open (15mm) by about 8-10psi. Shimming the stock wastegate will have it start to open at 4-5psi and fully open by 10-12.
"SOMEONE out there has to know the answer to this - what allows the wastegate to stay closed and build up pressure beyond the 1.2 bar limit provided by the wastegate spring? Is it the drop in pressure created above the diaphragm as the valve tries to move downwards and open or what?"
No, it's the CV that diverts pressure away from the wastegate and allows the spring to stay closed more. Ok, here's a quick synopsis on how the stock boost-control system works... I think you're getting boost-pressure (intake-manifold) mixed up with exhaust-pressure (headers & crossover).
The wastegate diaphragm is opened by boost-pressure coming from the intercooler pipe. There is a regulation valve in between, the CV-cycling valve. In the unpowered, passive OFF state, it lets through all pressure from the intercooler-pipe to the wastegate, as if the CV wasn't even there at all:
This is a failsafe default mode that's designed for safety. If something happens to the KLR or the CV fails, the system lets through ALL boost to the wastegate. The resulting boost is the effective spring-rate in the wastegate. As mentioned before, it starts to open at 2-3psi above atmospheric.
Since the bottom of wastegate diaphragm is vented to atmosphere, the pressure pushing down on the diaphram has to be about 2-3psi above atm, or 1.2-1.3 bar. Note that in the intercooler pipe, pressure is always atmospheric or above. Vacuum only exists in the intake-manifold after the restriction caused by the throttle-body. You might get a little bit of vacuum in the intercooler when you initially increase throttle under partial-throttle cruising, but not much. So effectively, pressure in the intercooler-pipe is atmospheric or above. So in the default unpowered state, the CV lets through all pressure and the most boost you'll get is 1.2 bar on the dash gauge.
Then the KLR computer turns on & off the CV with a duty-cycle curve like an injector as Gator_86_951 drew above. This causes the CV to divert pressure AWAY from the wastegate and back to the intake J-boot. This reduced pressure going to the wastegate allows the valve to stay closed more and build up boost:
Note the three vector directions. The ONLY thing closing the wastegate valve is the spring-tension. Opposing that is the pressure in the diaphragm and exhaust-pressure. Exhaust-pressure is NOT the same as boost-pressure. It goes up as a straight function of boost & RPM, while boost-pressure is managed by the boost-controller and turbo's compressor map. It's the sum of diaphragm pressure and exhaust pressure that acts on the wastegate spring:
Not that in the upper-RPMs, exhaust-pressure alone is all that's needed to open the wastegate valve. I've measured pressure of 10-50psi in the crossover under normal operations. Shimming the wastegate increases the spring-preload and helps it resist exhaust-pressure:
Note that pressure going to the wastegate's diaphragm (blue) is a direct in->out function of the mechanical boost-controller. As boost hits a certain level to open the check-valve, a certain pressure makes it past to the diaphragm. However, it doesn't take into account exhaust-pressures, and in the upper-RPMs, a mechanical boost-controller let's through too much pressure, thus opening the wastegate early and dumping boost. To get a flat-boost curve, you need something that can measure exhaust-pressure. An electronic boost-controller can do that through fuzzy logic inference:
It can through recording previous runs, figure out the dropping boost (learns exhaust-pressure indirectly). Thus in the upper-RPMs, even at the same 15psi boost, an EBC will slowly bleed off pressure going to the wastegate, thus keeping it closed tighter and tighter as exhaust-pressure increases.
As you guys can figure out by now, leaks in the boost-control hoses would leak out pressure that's sent to open the wastegate. The effects of leaks is to increase boost. In the early days, people actually purposely introduce leaks to increase boost, like drilling holes in the CyclingValve or using aquarium bleeder valves on the hoses. This has the effect off linearly increasing the boost-curve upwards.
So Jeff, you've done your testing correctly. Regardless of whether or not you plug up the nipple on the wastegate or clamp the line going to it, if you keep all pressure away from the diaphragm, you'll keep the wastegate fully closed. Just by unplugging the hose, you can expect to see 30psi+ from a stock turbo (ask me how I know
) If you're not getting that, there's something wrong other than your boost-control system, don't waste your time fixing hoses and leaks going to the wastegate.
Last edited by Danno; 11-01-2004 at 02:25 PM.
11-01-2004, 02:01 PM
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My english isn't the best but I'll try once more.
There can never be since the CV valve is never fully tight. There is always a slight leak which is routed to the J-boot.
If it was tight it still couldn't work like that. It is not hydraulics. The vacuum created when moving the valve a few mm is hardly measurable.
BTW, I don't mind your approach to learning
Bengt
As such, there was nothing preventing air from rushing in to the volume of space created on top of the WG diaphragm when the valve tried to move down.
If it was tight it still couldn't work like that. It is not hydraulics. The vacuum created when moving the valve a few mm is hardly measurable.
BTW, I don't mind your approach to learning
Bengt
11-01-2004, 02:04 PM
#23
Originally Posted by special tool
Just trying to help. MPD47 - you are not that far away from me. Send me a pm and I will find and fix your leak for free. 
But I like to fix my stuff myself. Unless it gets to the point where I've taken it apart multiple times, put it back together perfectly and it still doesnt work. Then you can help me. 
11-01-2004, 02:17 PM
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Wow, excellent write up Danno, although the last 3 pics aren't showing up for me. Very helpful, I guess I should try plugging that line to the wastegate and get onto boost CAREFULLY and see if I can build more than the 1.2 bar on the gauge.
That clears things up a lot for me.
That clears things up a lot for me.
11-01-2004, 02:19 PM
#25
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Thanks Bret... Strange... I'm having problems with pics too. First two shows up on IE, but not the last three. Using Firefox, I can't see the first two, but can see the last three. Must be some sort of hot-linking blocking or some sort. Let's see if they work if I upload them to my GURU server...
Ok, fixed the picture links...
Ok, fixed the picture links...
11-01-2004, 02:59 PM
#26
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Awesome write-up. It makes a lot of sense and I'm sure I'll end up either shimming up the wastegate or doing the Guru one at some point. Before I do that and end up putting more load on the turbocharger I need to figure out yet another problem - why the electric turbo water pump isn't working. Once I've got that diagnosed and I'm sure I've got adequate cooling to the turbocharger I'll start pushing it to get as much as I can out of it with some of the methods we've discussed. I'll check for proper operation tonight and eventually I can get it up to you and we'll tweak it & tune it properly.
11-01-2004, 10:23 PM
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Jeff, did you try and bypass the cycling valve yet tonight ? I didn't get a chance to try it on mine and was wondering if it was the solution to your (and my) problem.
11-02-2004, 05:26 AM
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Not the CV - well, not entirely.
I got everything back together and I will say the car runs a LOT better now; probably the fact it didn't have a humongous vaccum leak at the CV which is now repaired had something to do with that. That's the good news. The bad news is it's still not building boost above 1.2 bar, but I think I've found the problem for that - the J-boot is totally falling apart. I pulled it off after the boost-less test drive to check the sealing of the various hoses that plug into it and realized just how bad the thing was. It's literally crumbling when you try to flex it at all. Needless to say, I suspect this might be creating less-than-adequate vaccum through the line that runs off the J-boot to the CV, helping to close the wastegate valve. Car is grounded until I can scrape up the $100 for a new J-boot (probably next week sometime). I'll keep you posted.
I got everything back together and I will say the car runs a LOT better now; probably the fact it didn't have a humongous vaccum leak at the CV which is now repaired had something to do with that. That's the good news. The bad news is it's still not building boost above 1.2 bar, but I think I've found the problem for that - the J-boot is totally falling apart. I pulled it off after the boost-less test drive to check the sealing of the various hoses that plug into it and realized just how bad the thing was. It's literally crumbling when you try to flex it at all. Needless to say, I suspect this might be creating less-than-adequate vaccum through the line that runs off the J-boot to the CV, helping to close the wastegate valve. Car is grounded until I can scrape up the $100 for a new J-boot (probably next week sometime). I'll keep you posted.
11-02-2004, 08:31 AM
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Originally Posted by Porsche-O-Phile
Before I do that and end up putting more load on the turbocharger I need to figure out yet another problem - why the electric turbo water pump isn't working.
When you shut down the engine, the electric turbo water pump should run for 25 to 30 seconds. If it does not, the problem can either be the relay or the pump itself. Try running 12 volts to the pump connector and see if it runs. If it does not then you need a new pump (Ouch! Ask me how I know...)
11-02-2004, 10:52 AM
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I likewise suspect the pump is shot, but I'll test it tonight. I get no operation whatsoever under any circumstances, unless of course it has an ultra quiet whisper stealth mode.