Holy Rod Bearing, Batman
06-16-2022, 11:30 PM
#16
Burning Brakes
Join Date: Sep 2017
Location: Formerly the DPRK, now seeking political asylum in Oregon
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I'd for sure drop the girdle to inspect. It might aid in your decision.
If the bearings are bad, but the crank looks OK, it's easy enough to 'roll' the upper shells out of the block... but is the first bearing full circle? I forget...
There's an official tool (non-Porsche specific) for the job, although I've never seen one in person.
Using a cotter pin (with the head flattened) in the journal oil hole is also described... turn the crank, and the bearing shell slides out.
I've always been able to just push them out (carefully) with a small screwdriver.
Installation is the reverse operation...
Good luck, let us know what happens!
If the bearings are bad, but the crank looks OK, it's easy enough to 'roll' the upper shells out of the block... but is the first bearing full circle? I forget...
There's an official tool (non-Porsche specific) for the job, although I've never seen one in person.
Using a cotter pin (with the head flattened) in the journal oil hole is also described... turn the crank, and the bearing shell slides out.
I've always been able to just push them out (carefully) with a small screwdriver.
Installation is the reverse operation...
Good luck, let us know what happens!
06-17-2022, 05:02 PM
#17
Rennlist Member
Complete lack of oil pressure suggests a cracked/broken oil pick-up tube (a common failure). If it cracked on your way to school, it would not want to prime itself after sitting a bit. They crack near the base where the flange bolts to the girdle. Check that; you may have missed it when you disassembled the lower end, or perhaps you haven't removed it yet.
If this is the case, you've identified the root cause of the bearing failure since #2 goes first, then typically #3. Can you throw rod bearings in there and soldier on? In an emergency, sure. You may get away with it until you do a proper rebuild. Change you 'new' oil and filter in a hundred miles or so, then carry on! Use the ACL race rod bearings when you do the rebuild, and have your rods checked dimensionally due to heat generated from the failure.
MM
If this is the case, you've identified the root cause of the bearing failure since #2 goes first, then typically #3. Can you throw rod bearings in there and soldier on? In an emergency, sure. You may get away with it until you do a proper rebuild. Change you 'new' oil and filter in a hundred miles or so, then carry on! Use the ACL race rod bearings when you do the rebuild, and have your rods checked dimensionally due to heat generated from the failure.
MM
06-20-2022, 11:13 PM
#18
Cruisin'
Thread Starter
Episode 4: A Faltering Hope
Okay, maybe its not that bad. But the problem is not resolved yet. So far I have reassembled the bottom end of the engine; bearings, oil pan, belts and whatnot, etc. I didn't get any pictures, it was getting late and I was trying to have the oil pan back in before bedtime. All the other bearing journals looked good, I never would've guessed anything had gone wrong if I hadn't seen number 2 and (maybe) number 3. Nothing looked out of place, all went smoothly. Well, as smoothly as that gosh darn oil pan (Upside down, in the gravel, and mostly working with one arm) can be. I spun the engine over by hand without the spark plugs out and oil came out of the filter hole. To me, this was good news. In response to that news, I may have jumped the gun and decided I should go ahead and crank the engine to see if I was building pressure. Not necessarily start it and go for a ride, just crank it.
I did the bare minimum to get the engine crankable, and gave her a whirl. I saw oil come out the filter hole again, so I tossed the filter back on there, and cranked a bit more. I didn't really see any pressure, but the gauge bounced a bit maybe? Looked fluttery to me. Worth trying to start it for a moment. Or so I thought. I was young then, stupid. A fool. I didn't know any better. Anyway, it fired up as it usually does, but dryer. No oil pressure. I've played this game before so I shut it on down. I'm not as worried this time, everything on the bottom end is coated in assembly lube and I pushed oil through everything before I put it back together. I payed more attention to the lifters this time and they were definitely not full of oily goodness. That was the moment of faltering hope.
But then I heard a sound. Not a good sound, but a sound. What is this? Could it be? What's this stream of liquid, right here beside me?
Coolant. There was coolant coming out of the overflow. I popped the cap and gaw-lee gee, there was a lot of pressure in there. That was the moment of absolutely shattered hope.
To me that immediately says head gasket. But then I remembered I skipped a step. I wanted to pull the heat exchanger to see if it was blocked, but after seeing oil come out of the filter hole I boldly assumed that there was nothing blocking it. But my theory now is that there could be enough blocking it that a little oil gets by, but not enough to pressurize the rest of the engine. This means there is probably a lot of oil in the coolant somewhere, but I still don't see any in the reservoir. Maybe it didn't make it that far yet.
So, possibilities, to me anyway, are head gasket or heat exchanger. I'll pull the heat exchanger (like I should've done first) next and inspect the situation. If I find nothing, I guess the head gasket is blown and I'll just go ahead and roll the car into the nearest body of water. If there are any other possibilities for cranking an engine to cause significant coolant pressure, do tell. This is more of a progress post than a solution post, and I did indeed wait until the end to mention that. I'll update later this week.
Here's the summary of questions:
1. Does the theory make sense? Oil pushing past the heat exchanger o-ring and into the coolant, pressurizing it instead of the oil passages? I think this would push the rod bearing into the cause category rather than a symptom.
2. Any other way for the coolant to get pressurized?
Okay, maybe its not that bad. But the problem is not resolved yet. So far I have reassembled the bottom end of the engine; bearings, oil pan, belts and whatnot, etc. I didn't get any pictures, it was getting late and I was trying to have the oil pan back in before bedtime. All the other bearing journals looked good, I never would've guessed anything had gone wrong if I hadn't seen number 2 and (maybe) number 3. Nothing looked out of place, all went smoothly. Well, as smoothly as that gosh darn oil pan (Upside down, in the gravel, and mostly working with one arm) can be. I spun the engine over by hand without the spark plugs out and oil came out of the filter hole. To me, this was good news. In response to that news, I may have jumped the gun and decided I should go ahead and crank the engine to see if I was building pressure. Not necessarily start it and go for a ride, just crank it.
I did the bare minimum to get the engine crankable, and gave her a whirl. I saw oil come out the filter hole again, so I tossed the filter back on there, and cranked a bit more. I didn't really see any pressure, but the gauge bounced a bit maybe? Looked fluttery to me. Worth trying to start it for a moment. Or so I thought. I was young then, stupid. A fool. I didn't know any better. Anyway, it fired up as it usually does, but dryer. No oil pressure. I've played this game before so I shut it on down. I'm not as worried this time, everything on the bottom end is coated in assembly lube and I pushed oil through everything before I put it back together. I payed more attention to the lifters this time and they were definitely not full of oily goodness. That was the moment of faltering hope.
But then I heard a sound. Not a good sound, but a sound. What is this? Could it be? What's this stream of liquid, right here beside me?
Coolant. There was coolant coming out of the overflow. I popped the cap and gaw-lee gee, there was a lot of pressure in there. That was the moment of absolutely shattered hope.
To me that immediately says head gasket. But then I remembered I skipped a step. I wanted to pull the heat exchanger to see if it was blocked, but after seeing oil come out of the filter hole I boldly assumed that there was nothing blocking it. But my theory now is that there could be enough blocking it that a little oil gets by, but not enough to pressurize the rest of the engine. This means there is probably a lot of oil in the coolant somewhere, but I still don't see any in the reservoir. Maybe it didn't make it that far yet.
So, possibilities, to me anyway, are head gasket or heat exchanger. I'll pull the heat exchanger (like I should've done first) next and inspect the situation. If I find nothing, I guess the head gasket is blown and I'll just go ahead and roll the car into the nearest body of water. If there are any other possibilities for cranking an engine to cause significant coolant pressure, do tell. This is more of a progress post than a solution post, and I did indeed wait until the end to mention that. I'll update later this week.
Here's the summary of questions:
1. Does the theory make sense? Oil pushing past the heat exchanger o-ring and into the coolant, pressurizing it instead of the oil passages? I think this would push the rod bearing into the cause category rather than a symptom.
2. Any other way for the coolant to get pressurized?
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Autobreza (06-21-2022)
06-21-2022, 10:14 AM
#22
Cruisin'
Thread Starter
06-21-2022, 11:31 AM
#23
Three Wheelin'
Join Date: Oct 2021
Location: Southern WI - 89S2 Megasquirt PNP
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06-22-2022, 10:49 AM
#24
Addict
Rennlist Member
Rennlist Member
Given your location I recommend getting a running engine or parts car. A quick look is encouraging:
https://richmond.craigslist.org/pts/...487290662.html
https://richmond.craigslist.org/pts/...487290662.html
06-22-2022, 01:08 PM
#25
Drifting
Episode 4: A Faltering Hope
Okay, maybe its not that bad. But the problem is not resolved yet. So far I have reassembled the bottom end of the engine; bearings, oil pan, belts and whatnot, etc. I didn't get any pictures, it was getting late and I was trying to have the oil pan back in before bedtime. All the other bearing journals looked good, I never would've guessed anything had gone wrong if I hadn't seen number 2 and (maybe) number 3. Nothing looked out of place, all went smoothly. Well, as smoothly as that gosh darn oil pan (Upside down, in the gravel, and mostly working with one arm) can be. I spun the engine over by hand without the spark plugs out and oil came out of the filter hole. To me, this was good news. In response to that news, I may have jumped the gun and decided I should go ahead and crank the engine to see if I was building pressure. Not necessarily start it and go for a ride, just crank it.
I did the bare minimum to get the engine crankable, and gave her a whirl. I saw oil come out the filter hole again, so I tossed the filter back on there, and cranked a bit more. I didn't really see any pressure, but the gauge bounced a bit maybe? Looked fluttery to me. Worth trying to start it for a moment. Or so I thought. I was young then, stupid. A fool. I didn't know any better. Anyway, it fired up as it usually does, but dryer. No oil pressure. I've played this game before so I shut it on down. I'm not as worried this time, everything on the bottom end is coated in assembly lube and I pushed oil through everything before I put it back together. I payed more attention to the lifters this time and they were definitely not full of oily goodness. That was the moment of faltering hope.
But then I heard a sound. Not a good sound, but a sound. What is this? Could it be? What's this stream of liquid, right here beside me?
Coolant. There was coolant coming out of the overflow. I popped the cap and gaw-lee gee, there was a lot of pressure in there. That was the moment of absolutely shattered hope.
To me that immediately says head gasket. But then I remembered I skipped a step. I wanted to pull the heat exchanger to see if it was blocked, but after seeing oil come out of the filter hole I boldly assumed that there was nothing blocking it. But my theory now is that there could be enough blocking it that a little oil gets by, but not enough to pressurize the rest of the engine. This means there is probably a lot of oil in the coolant somewhere, but I still don't see any in the reservoir. Maybe it didn't make it that far yet.
So, possibilities, to me anyway, are head gasket or heat exchanger. I'll pull the heat exchanger (like I should've done first) next and inspect the situation. If I find nothing, I guess the head gasket is blown and I'll just go ahead and roll the car into the nearest body of water. If there are any other possibilities for cranking an engine to cause significant coolant pressure, do tell. This is more of a progress post than a solution post, and I did indeed wait until the end to mention that. I'll update later this week.
Here's the summary of questions:
1. Does the theory make sense? Oil pushing past the heat exchanger o-ring and into the coolant, pressurizing it instead of the oil passages? I think this would push the rod bearing into the cause category rather than a symptom.
2. Any other way for the coolant to get pressurized?
Okay, maybe its not that bad. But the problem is not resolved yet. So far I have reassembled the bottom end of the engine; bearings, oil pan, belts and whatnot, etc. I didn't get any pictures, it was getting late and I was trying to have the oil pan back in before bedtime. All the other bearing journals looked good, I never would've guessed anything had gone wrong if I hadn't seen number 2 and (maybe) number 3. Nothing looked out of place, all went smoothly. Well, as smoothly as that gosh darn oil pan (Upside down, in the gravel, and mostly working with one arm) can be. I spun the engine over by hand without the spark plugs out and oil came out of the filter hole. To me, this was good news. In response to that news, I may have jumped the gun and decided I should go ahead and crank the engine to see if I was building pressure. Not necessarily start it and go for a ride, just crank it.
I did the bare minimum to get the engine crankable, and gave her a whirl. I saw oil come out the filter hole again, so I tossed the filter back on there, and cranked a bit more. I didn't really see any pressure, but the gauge bounced a bit maybe? Looked fluttery to me. Worth trying to start it for a moment. Or so I thought. I was young then, stupid. A fool. I didn't know any better. Anyway, it fired up as it usually does, but dryer. No oil pressure. I've played this game before so I shut it on down. I'm not as worried this time, everything on the bottom end is coated in assembly lube and I pushed oil through everything before I put it back together. I payed more attention to the lifters this time and they were definitely not full of oily goodness. That was the moment of faltering hope.
But then I heard a sound. Not a good sound, but a sound. What is this? Could it be? What's this stream of liquid, right here beside me?
Coolant. There was coolant coming out of the overflow. I popped the cap and gaw-lee gee, there was a lot of pressure in there. That was the moment of absolutely shattered hope.
To me that immediately says head gasket. But then I remembered I skipped a step. I wanted to pull the heat exchanger to see if it was blocked, but after seeing oil come out of the filter hole I boldly assumed that there was nothing blocking it. But my theory now is that there could be enough blocking it that a little oil gets by, but not enough to pressurize the rest of the engine. This means there is probably a lot of oil in the coolant somewhere, but I still don't see any in the reservoir. Maybe it didn't make it that far yet.
So, possibilities, to me anyway, are head gasket or heat exchanger. I'll pull the heat exchanger (like I should've done first) next and inspect the situation. If I find nothing, I guess the head gasket is blown and I'll just go ahead and roll the car into the nearest body of water. If there are any other possibilities for cranking an engine to cause significant coolant pressure, do tell. This is more of a progress post than a solution post, and I did indeed wait until the end to mention that. I'll update later this week.
Here's the summary of questions:
1. Does the theory make sense? Oil pushing past the heat exchanger o-ring and into the coolant, pressurizing it instead of the oil passages? I think this would push the rod bearing into the cause category rather than a symptom.
2. Any other way for the coolant to get pressurized?
Did you find any oil in coolant if you drained the radiator?
The engine oil pressure was essentially zero.
If the head gasket is leaking, the rotation of the engine piston compresses the air in the cylinder and the air is relieved into the coolant system. Your description of the time it took to relieve the pressure sounds like a head gasket leak.
What to do???? Remove the oil filter. With a plastic house and funnel, add oil into the slotted hole to fill the oil pump cavity. Rotate the engine CCW help draw the oil into the discharge side of the pump. Button things up. Disconnect electrical fuel harness from each injector, remove spark plugs, crank engine with starter, might take several bumps to build oil pressure.
06-22-2022, 03:59 PM
#26
Rennlist Member
Pressurizing the crankcase through the dipstick tube and cranking it over worked really well to build oil pressure when I tried it. I hadn't tried to actually start it previously, but it wasn't building pressure just cranking alone after repairs.
06-23-2022, 09:05 AM
#27
Drifting
That is good idea, I did not menttion it because of OP working outside but if he as access to compressed air. go for it. I limit the pressure to 20 psig and plug the crankcase evacuation hose downstream of the AOS so can pressurize the crankcase. I use this process several times with great success.
06-23-2022, 09:40 AM
#28
Instructor
My turbo took ages to build pressure after I resealed the oil filter housing, I thought something was wrong but kept cranking it on the starter and eventually it started to build pressure.
Fingers crossed for you!
Fingers crossed for you!
06-24-2022, 05:58 AM
#29
Check the crank bolt the oil pump is friction driven not a direct drive from the crank
06-24-2022, 06:14 PM
#30
I ran into oil pressure issues on my 944 as well. Right before I bought it the previous owner changed the heat exchanger gaskets as preventative maintenance. A few weeks after I bought it, I went to start it for a drive and there was no oil pressure. I tried priming the pump in all sorts of ways and checked the torque on crank bolt. Eventually, I just decided to check the OPRV. It turns out the previous owner didn’t align the heat exchanger housing correctly and the OPRV was bound inside and broken. Replaced the broken oprv and correctly aligned the housing, primed the oil pump and just like oil pressure was back.
TLDR: check your OPRV/heat exchanger housing. It very well could be causing your oil pressure issues.
TLDR: check your OPRV/heat exchanger housing. It very well could be causing your oil pressure issues.
Last edited by Arty92; 06-24-2022 at 06:20 PM.