1. Is it possible for the thermostat to be installed backwards? I believe I installed mine spring up (towards the water pump and engine), which makes sense to be correct.
2. When the engine is running at high RPMs (4000+), where does all that coolant go when the thermostat is still closed? I'm not sure I understand the coolant flow direction. I thought I did: Coolant is pushed through the engine from the water pump, exits the engine at the water outlet and goes into the radiator, while some goes through the 3/4" hose that leads to the heater core. Coolant from the heater core feeds into the water pump behind the engine. When the thermostat opens, coolant flows through the radiator and is sucked up from the lower pipe into the water pump which pushes it through the engine. So all that coolant flow when the thermostat is closed recirculates through the heater core? Seems like the only path of motion available when the thermostat is closed.
Reason I ask, I've been dealing with cooling system issues for a while. From a cracked plastic connector, bad water outlet o-ring, and deteriorated hose, I have everything seemingly sealed up (zero external leaks). Problem is when I am under heavy throttle, the car sometimes will get hot (220-240+), and then quickly cool down to normal temperatures and if I drive like a normal person it will stay perfectly normal (185-190 F) throughout the rest of my trip. It acts, to me, like it has a big air pocket trapped somewhere or something that gets "burped" out under throttle. Coolant comes out with this excess air pressure, unfortunately, as a high pressure stuff likes to go somewhere with low pressure. Last night I did a long WOT run on the highway and the car got hot and wouldn't return to normal, heater went cold, I pulled over and shut it off. My coolant got blown out through the overflow hose. Filled it up, took off, car got somewhere around 216 and then did it's "insta-drop" and quickly cooled down to normal and stayed there for the rest of my trip.
I ran the car this morning from cold with the cap off for about 45 minutes, revving and squeezing hoses and observing the temperature, attempting to "burp" it. Nothing came out, the car idled at 190 solid once it got there.
Suggestions? Replace the thermostat with an ACDelco one? Clogged radiator/heater core that can flow well at low RPM but overpressurizes at high RPM? That also seems to make good sense to me....
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
Weird, I had the same issue last year with coolant leaking out of my overflow only under boost, yet the car would not run hot.
Yes you can install the thermostat upside down, I always question myself after I installed mine because I was scared I did it wrong, but all is good with mine.
What degree thermostat do you have? I would recommend the 160* one, that is what I have and have had no problem since I installed that one, even with 8 hours on the dyno with no issues. I used to have the 180* one with issues.
~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ
how do you cool your turbo ? the
hose routing I mean
Location: Montreal, Quebec
The last three times i replaced a thermostat in a LD9 the thermostat would only go in one way due to how it fits in the black metal piece that wraps around the bottom of the oil pan. If put in upside down it will not seal.
maximus overdrive wrote:The last three times i replaced a thermostat in a LD9 the thermostat would only go in one way due to how it fits in the black metal piece that wraps around the bottom of the oil pan. If put in upside down it will not seal.
Thought so.
mcmoney wrote:how do you cool your turbo ? the
hose routing I mean
No splices to run to the turbo at the moment. It used to be hooked up, but I wanted to rule that heat generator out of the equation, so my hose routing is essentially stock. I'd rather kill the turbo than my engine.
WHITECAVY wrote:What degree thermostat do you have? I would recommend the 160* one, that is what I have and have had no problem since I installed that one, even with 8 hours on the dyno with no issues. I used to have the 180* one with issues.
I have a Duralast 180. If my car can stay under 196 the entire time I'm at the track, even after 5 runs, I think my cooling system should work when it works. Something else seems to be affecting it. Either the thermostat is stuck occasionally or something else. I thought about putting in a 160, but that would change the dynamics of how open it is and change the flow characteristics for sure. The problem I've had is the temps have gone way up there sometimes (240+) and even if I had a 160 thermostat, it's going to be full open at that point just like the 180, so the problem either lies with a faulty/sticky thermostat, air pocket, or a clog I assume. Easiest thing to do is the thermostat though, so either I'll get the ACDelco original, or a Duralast 160. Probably the 160 just for the hell of it to experience what the temps do with one that starts opening 20 degrees earlier.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
huh? how can you install it upside down? if you try it will not fit. you would physically have to smash it between the water pump and neck to do so.
If it takes forever.... I will die trying. Underdog Racing
Yup, we established that.
NEW INFO
I found another water outlet leak again, so that's probably where all my problems are stemming from. Stupid aftermarket plastic junk with @!#$ty o-rings. I'm going to have my friend make me a new one from stainless steel on Monday, so that should be cool (literally).
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
I always seal the outlet with RTV. Its a bad design with the little ass o-ring in there.
the o ring is fine its the housing that always cracks.
Ahh I didnt know you cant SEAL the thermostat upside down, I usually just just put it to the housing upside down, then realized it was wrong right away. Good thing I never tried to bolt it up like that lol
~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ
That leak is probably the main problem, but I would recommend getting a new expansion tank cap. I had an intermittent issue with my z that was similar and thats what it was. Being that its venting coolant and heating up excessively its definitely a possibility thats its going bad.
Already have a new ACDelco reservoir and cap, but if this doesn't fix it, that's my next choice.
Goodbye @!#$ty o-ring seal, hello big flat gasket sealing surface.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
I still need to visit him one of these days to discuss some ideas.
