Coolant temperature issues.. Advice?? Ideas??

Lee_MA61

Lee_MA61

Leon Wilson III
Jan 31, 2007
148
0
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37
Norwalk, IA
Hey thanks for taking the time to help me out.

Alright I have a 91' Supra Turbo, the car runs strong. Although the coolant temperature varies at times after ~45mins of driving..

So I always stop and check rad at it's pushing steam like a steam boat. So I'm thinking BHG.. I let it cool down and fill the system up with fresh coolant. I observed little bubbles coming out the filler neck when the car was running. Also I've tried to park it up hill to "burp" the system, hoping that it's just a cause of vapour lock..

Well after several attempts at trying to remove this imaginary vapour lock. I decided to give in and think it's a BHG.

So before tearing the head apart I decide to do a comperssion test. The test results were 150psi - 152 psi (@ 102 degrees (F) with above %50 humidity) across all cylinders. So... BHG seems to be ruled out at this point...

What I think might be the problem is.. My Turbocharger.. Well my intercooler piping is covered in oil on the inside (much more than normal). The turbo also has far more than "standard" shaft play both up down and in and out. So it is blown and needs to be replaced.

The question is.. Is it possible that the turbocharger is pressurising my coolant system due to bad seals and bearings?? The car doesn't smoke "anti-freeze" smoke and doesn't smoke at all. For that matter..

Anyways the above probably doesn't make sense at all the times. But the basic idea is.. Can a bad turbo cause my car to get close to overheating?

Alright, let me know.
Thanks guys!

Leon Wilson III
 
Bishop92t

Bishop92t

Supramania Contributor
Apr 18, 2005
773
0
0
USA
www.ma70.com
If the turbo was leaking coolant that could cause problems, otherwise no. With the car cold, fill the radiator to the top and put the cap on. Start the car and start squeezing and pushing on the various coolant hoses. Generally they spring leaks at the clamp, by squeezing near it you can make the leak much more apparent. Just be careful you don't burn yourself.

Is it the stock temperature gauge varying or an aftermarket?
 
Lee_MA61

Lee_MA61

Leon Wilson III
Jan 31, 2007
148
0
0
37
Norwalk, IA
Stock. But the coolant system has bubbles and becomes pressurized after awhile.

Today I removed the turbo from the car's coolant system. I placed it on it's own independent system. I then filled the radiator and left the cap off. After quite some time of running it still pushed bubbles.

So the turbo idea is blown out of the idea.

What next?

Bad seal around the water pump, sucking air?

Bad hoses that are some how sucking air but not leaking coolant?

I know the compression test doesn't mean much. But for it to be a BHG the variance between the cylinders would be much greater than 3 psi.

I'll check the hoses, and yes my turbo feed lines were rock hard. Maybe there is more..

Let me know what you guys think.

Thanks,
Leon Wilson III
 
I

IJ.

Grumpy Old Man
Mar 30, 2005
38,728
0
0
62
I come from a land down under
Leon: It could be leaking at high boost/temps then settle back down when it cools enough not to affect the comp test. (Sometimes a crack will exhibit this behaviour)

Grab a torque wrench and run the head bolts to see if there are any loose ones before tearing into it.
 
jetjock

jetjock

creepy-ass cracka
Jul 11, 2005
9,439
0
0
Redacted per Title 18 USC Section 798
Lee_MA61 said:
So before tearing the head apart I decide to do a comperssion test. The test results were 150psi - 152 psi (@ 102 degrees (F) with above %50 humidity) across all cylinders. So... BHG seems to be ruled out at this point."
Click to expand...

Bad news: A good compression test in no way rules out a BHG.

edit: IJ beat me ;)
 
CampbellsChunkySoupra

CampbellsChunkySoupra

best be eating your soup!
Jan 28, 2007
620
0
0
Norwalk, IA
www.dragsource.net
i have something to add as i am also helping Leon try to figure out the troubles with this car. it seems like it overheats when it is driven at cruising speeds and then when u go straight to city driving or to a stop with the car idling, it starts to shoot up temperature wise.

the tool that sold Leon the car had filled the ENTIRE motor with water before we trecked off on the 1.5 hour drive back home. i know we were stupid for not checking the coolant itself.. so when we were taking it home, i got a boost leak in my car so we pulled over and he popped his hood and thats when we seen that it was overheating terribly.

could a motor BHG due to running 100% water on a hot and humid day? the water in the radiator/overflow tank was steaming hot so that makes me think that it was boiling, duh... i dont know, just adding some thoughts if this helps at all.

-Tyler
 
Datsrboi

Datsrboi

Loud pipes Save Lives
Jul 31, 2007
797
0
0
Haltom Texas
www.cardomain.com
OMG SOUNDS JUST LIKE MY PROBLEM RIGHHHHHHHHHHTTTTTTTT NOW.


Still waiting for my coolant test stuff. in the mean time I am draining out my coolant tomorrow and sticking a pressure water hose through the hoses and see if theres some sort of blockade.

Try filling your car up and start the car. Do not rev it and just let it idle for 5 to 10 minutes and see if it starts shooting out of the resorvoir. If it does then we both have the same darn case.


My guess is that we both do not have BHG, It might be our water coolant flow is not flowing so the car heats up incorrectly and shoots the coolant out because its not cooling down.
 
Lee_MA61

Lee_MA61

Leon Wilson III
Jan 31, 2007
148
0
0
37
Norwalk, IA
I think we might have similair problems..

I re torqued the head bolts to 75 ft/lbs. as a member recommended. What is the re torque actually supposed to be??

Tomorrow I'm going to have the coolant system blasted out. Well flushed haha Hopefully that will blow out some crud and prove to me it's not a BHG.

Still I know it could be the start of one, although I've run many 5Ms that started to BHG. On those M series engines you can feel it start to go. And well this engine still runs to strong to be a BHG.

Also my turbo coolant lines were rock hard and where full of scale and deposits.. Hopefully it's just some crusties and not a BHG..

Any other words of advice??

Thanks,
 
WhtMa71

WhtMa71

D0 W3RK
Apr 24, 2007
1,813
0
36
Macon, GA
Get a radiator pressure test kit and use it. If it doesnt hold the pressure it says on the cap then you have a leak somewhere.
 
Datsrboi

Datsrboi

Loud pipes Save Lives
Jul 31, 2007
797
0
0
Haltom Texas
www.cardomain.com
Lee_MA61 said:
I think we might have similair problems..

I re torqued the head bolts to 75 ft/lbs. as a member recommended. What is the re torque actually supposed to be??

Tomorrow I'm going to have the coolant system blasted out. Well flushed haha Hopefully that will blow out some crud and prove to me it's not a BHG.

Still I know it could be the start of one, although I've run many 5Ms that started to BHG. On those M series engines you can feel it start to go. And well this engine still runs to strong to be a BHG.

Also my turbo coolant lines were rock hard and where full of scale and deposits.. Hopefully it's just some crusties and not a BHG..

Any other words of advice??

Thanks,
Click to expand...


Check your Water pump.. I do not know if this is the reason why but I think its shooting coolant out the reservoir because water is not circulating... I found this from mine today. NO idea if its the reason why but I did pressure water through the system and saw no resistances. But if anyone has advice let me know. The water pump SPINS freely.

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