Overheating after WP replacement... Place your bets...
10-11-2010, 06:14 PM
#46
Team Owner
do this first..
Did you let the engine warm up with the cap off??No, I did not...
To fill the 928 coolant system, fill till the level reaches the seam then run the car with the heater on till the fans come on cap off,
then install the cap drive for about 5 miles with heater on then park it let it cool off then top up as necessary the system is a self bleeding system
Did you let the engine warm up with the cap off??No, I did not...
To fill the 928 coolant system, fill till the level reaches the seam then run the car with the heater on till the fans come on cap off,
then install the cap drive for about 5 miles with heater on then park it let it cool off then top up as necessary the system is a self bleeding system
10-11-2010, 07:41 PM
#48
Burning Brakes
Thread Starter
do this first..
Did you let the engine warm up with the cap off??No, I did not...
To fill the 928 coolant system, fill till the level reaches the seam then run the car with the heater on till the fans come on cap off,
then install the cap drive for about 5 miles with heater on then park it let it cool off then top up as necessary the system is a self bleeding system
Did you let the engine warm up with the cap off??No, I did not...
To fill the 928 coolant system, fill till the level reaches the seam then run the car with the heater on till the fans come on cap off,
then install the cap drive for about 5 miles with heater on then park it let it cool off then top up as necessary the system is a self bleeding system
I'm tempted to go back and try this before pulling the T-stat. Having to break into the fuel lines is not looking exciting at the moment.
10-11-2010, 08:53 PM
#49
Rennlist Member
no do NOT do that. by the time that the engine gets to temp, it will have localized boiling and expansion that air will be introduced to the system. once you burp the system, tighten the cap and then run it. it will take more water out of the expansion tank and re-fil to over the seam line when it cools. (i.e. no pressure in the system)
this stuff is not that complicated. you open the cap, squeaze the lines like you are milking a cow and the thats it. cap back on and go drive. if the fans dont go on, you have three issues possible. bad water pump, bad t-stat or bad radiator (clogged).
this stuff is not that complicated. you open the cap, squeaze the lines like you are milking a cow and the thats it. cap back on and go drive. if the fans dont go on, you have three issues possible. bad water pump, bad t-stat or bad radiator (clogged).
10-11-2010, 09:04 PM
#50
Rennlist Member
sqeezing the hoses proves nothing about the radiator, as all the "rails" are parrallel to the side tanks, so if half them are clogged,, then things will "appear" normal.
squeeze the hoses to push all the air in to the reservior. then release slowly, as it is pulling water from the reservior but air can enter the system if you release too fast. eventually, you will be squeezing the hoses and it will feel air free. you are done at this point.
overheating, and no fans, means the lower hose is cool to the touch, or not that hot. the radiator will be cool down low, if you can feel down there. this means its too cool for the fans to come on. when they come on, the system is very warm to the touch, both top and bottom hoses.
jamming the t-stat is the end all catch all test. (jamming it open and reassembling) there are two 10mm bolts, thats it! dont over tighten, and make sure you use a new o ring or one that is in good shape.
jamming the T-stat will force it into operating mode and just take forever for the engine to heat up. not a big deal, especailly on a hot day or racing. if it still overheats, you know the drill! water pump has failed or radiator is bad. test for circulation while you have the jammed t-stat in there. water flows out of the lower hose about a medium water hose flow from your garden. use a second lower hose (spare) to connect to the lower radiator hose connection point on the engine and feed water to it from the garden hose as you rev the engine. If it doesnt take water while its running, pump is bad or radiator is clogged. then, you can by pass the radiator to elimiate that, but generally, its probably the water pump.
squeeze the hoses to push all the air in to the reservior. then release slowly, as it is pulling water from the reservior but air can enter the system if you release too fast. eventually, you will be squeezing the hoses and it will feel air free. you are done at this point.
overheating, and no fans, means the lower hose is cool to the touch, or not that hot. the radiator will be cool down low, if you can feel down there. this means its too cool for the fans to come on. when they come on, the system is very warm to the touch, both top and bottom hoses.
jamming the t-stat is the end all catch all test. (jamming it open and reassembling) there are two 10mm bolts, thats it! dont over tighten, and make sure you use a new o ring or one that is in good shape.
jamming the T-stat will force it into operating mode and just take forever for the engine to heat up. not a big deal, especailly on a hot day or racing. if it still overheats, you know the drill! water pump has failed or radiator is bad. test for circulation while you have the jammed t-stat in there. water flows out of the lower hose about a medium water hose flow from your garden. use a second lower hose (spare) to connect to the lower radiator hose connection point on the engine and feed water to it from the garden hose as you rev the engine. If it doesnt take water while its running, pump is bad or radiator is clogged. then, you can by pass the radiator to elimiate that, but generally, its probably the water pump.
We'll it's time to start. And I've gotten a ton of feedback and great suggestions.
Formulating a plan of attack is pretty hard. I will add one more observation as it relates to flow through the radiator. I noted that squeezing either top hose or bottom hose had essentially the same effect on the reservoir with back-flow. I believe it is a fair assumption that overall, flow from the block through the radiator to the lower hose is unhindered.
But the unknowns are 1) is there an air pocket between the radiator and the t-stat, 2) is the water pump is moving water, or 3) is the t-stat opening.
Greg - I take your comments about "looking at what you did" pretty seriously. I suspect that I did do something wrong in my repair and that the right thing to do is to back-track.
But I'm hedging my bets (and trying to short-cut?). I'm going to try to bleed out the system first. Then pop out the T-stat first and see if it's working correctly. If that doesn't work, I'm going back in.
Along the way, I'm going to try to figure out if that radiator sensor is broken or not.
Formulating a plan of attack is pretty hard. I will add one more observation as it relates to flow through the radiator. I noted that squeezing either top hose or bottom hose had essentially the same effect on the reservoir with back-flow. I believe it is a fair assumption that overall, flow from the block through the radiator to the lower hose is unhindered.
But the unknowns are 1) is there an air pocket between the radiator and the t-stat, 2) is the water pump is moving water, or 3) is the t-stat opening.
Greg - I take your comments about "looking at what you did" pretty seriously. I suspect that I did do something wrong in my repair and that the right thing to do is to back-track.
But I'm hedging my bets (and trying to short-cut?). I'm going to try to bleed out the system first. Then pop out the T-stat first and see if it's working correctly. If that doesn't work, I'm going back in.
Along the way, I'm going to try to figure out if that radiator sensor is broken or not.
10-11-2010, 09:11 PM
#51
Burning Brakes
Thread Starter
Other than tearing it down, what's the fastest way to prove/disprove the water pump as the issue?
I've heard of folks disconnecting the top hose and pointing it out of the engine compartment....
I've heard of folks disconnecting the top hose and pointing it out of the engine compartment....
10-11-2010, 09:16 PM
#52
Three Wheelin'
Join Date: Feb 2009
Location: Washington "Dc"
Posts: 1,810
Likes: 0
Received 0 Likes
on
0 Posts
When in doubt, Do Over.
Why risk it? All you need is another gasket for the WP, and the second time is always faster than the first (With these types of things..)
Why risk it? All you need is another gasket for the WP, and the second time is always faster than the first (With these types of things..)
10-11-2010, 09:43 PM
#53
Rennlist Member
Join Date: Oct 2005
Location: Gatineau, Québec, Canada
Posts: 5,168
Received 1,289 Likes
on
490 Posts
As fare as I knowm, a good and easy way to know if there is flow or not is to put your heater to full warm with the car running. If you don't get heat, there is no flow.
If there is no air trapped inside the system and the thermostat is working properly, you probably have a bad pump or the system is cloged with something (like a rag maybe!).
Mark is right. If your pump is bad, you won't have any circulation and the upper hose will be quite warm and the lower one will be a lot cooler and both fans won't come on as the rad is too cool to triger the switch.
That is exactly what happend to me last spring.
And, if you have to go to the pump again, it is a lot faster and easier the second time!
Good luck.
If there is no air trapped inside the system and the thermostat is working properly, you probably have a bad pump or the system is cloged with something (like a rag maybe!).
Mark is right. If your pump is bad, you won't have any circulation and the upper hose will be quite warm and the lower one will be a lot cooler and both fans won't come on as the rad is too cool to triger the switch.
That is exactly what happend to me last spring.
And, if you have to go to the pump again, it is a lot faster and easier the second time!
Good luck.
10-11-2010, 09:47 PM
#54
Rennlist Member
thats what Ive described, but you need to short circuit the t-stat first.
it takes 10min, then pulling hoses and starting the car up takes another 5 min.
i used a spare lower radiator hose and connected it to the t-stat housing. you pour water in it as the engine starts. the "real" lower hose gets pointed over the fender or in a direction where you wont get the water where you dont want it. I have also made a clear pipe from home depot, to see the water movement before I figured out that the spare pipe was an easier way to confirm movement. it is a good way to isolate the radiator though.
it takes 10min, then pulling hoses and starting the car up takes another 5 min.
i used a spare lower radiator hose and connected it to the t-stat housing. you pour water in it as the engine starts. the "real" lower hose gets pointed over the fender or in a direction where you wont get the water where you dont want it. I have also made a clear pipe from home depot, to see the water movement before I figured out that the spare pipe was an easier way to confirm movement. it is a good way to isolate the radiator though.
10-11-2010, 10:11 PM
#55
Burning Brakes
Thread Starter
thats what Ive described, but you need to short circuit the t-stat first.
it takes 10min, then pulling hoses and starting the car up takes another 5 min.
i used a spare lower radiator hose and connected it to the t-stat housing. you pour water in it as the engine starts. the "real" lower hose gets pointed over the fender or in a direction where you wont get the water where you dont want it. I have also made a clear pipe from home depot, to see the water movement before I figured out that the spare pipe was an easier way to confirm movement. it is a good way to isolate the radiator though.
it takes 10min, then pulling hoses and starting the car up takes another 5 min.
i used a spare lower radiator hose and connected it to the t-stat housing. you pour water in it as the engine starts. the "real" lower hose gets pointed over the fender or in a direction where you wont get the water where you dont want it. I have also made a clear pipe from home depot, to see the water movement before I figured out that the spare pipe was an easier way to confirm movement. it is a good way to isolate the radiator though.
10-11-2010, 10:50 PM
#56
Team Owner
did you do this first???
if not,
please follow the instructions and see what happens you may just have air in the system and it is not full .....
To fill the 928 coolant system, fill till the level reaches the seam then run the car with the heater on till the fans come on cap off,
then install the cap drive for about 5 miles with heater on then park it let it cool off then top up as necessary the system is a self bleeding system
if not,
please follow the instructions and see what happens you may just have air in the system and it is not full .....
To fill the 928 coolant system, fill till the level reaches the seam then run the car with the heater on till the fans come on cap off,
then install the cap drive for about 5 miles with heater on then park it let it cool off then top up as necessary the system is a self bleeding system
10-12-2010, 03:15 AM
#57
Rennlist Member
mine was pretty straight forward. I dont know what yours exactly looks like. I have a lot of stuff missing due to it being mostly a race car.
can you get some small 10mm socket in there with an extension and swivel?
can you get some small 10mm socket in there with an extension and swivel?
10-12-2010, 10:05 PM
#58
Burning Brakes
Thread Starter
did you do this first???
if not, please follow the instructions and see what happens you may just have air in the system and it is not full .....
To fill the 928 coolant system, fill till the level reaches the seam then run the car with the heater on till the fans come on cap off,
then install the cap drive for about 5 miles with heater on then park it let it cool off then top up as necessary the system is a self bleeding system
if not, please follow the instructions and see what happens you may just have air in the system and it is not full .....
To fill the 928 coolant system, fill till the level reaches the seam then run the car with the heater on till the fans come on cap off,
then install the cap drive for about 5 miles with heater on then park it let it cool off then top up as necessary the system is a self bleeding system
10-13-2010, 12:17 AM
#60
Team Owner
there is a possibility that since the filling procedure wasnt followed the engine may have an airpocket . The heater needs to be opened and filled to assist with getting the air out of the cooling system.
Run the car with the cap off and the heater on,
keep an eye on the gauge if it gets close to the red line then shut it off.
Run the car with the cap off and the heater on,
keep an eye on the gauge if it gets close to the red line then shut it off.