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I had my engine/drivetrain/turbo kit in a G sedan and it ran just fine. Just finished swapping into my new Z body and now it runs hot. It doesn't overheat, but the coolant is always between 200-210 Fahrenheit cruising or driving hard or just idling. I noticed the radiator fans do not turn off once they turn on for the day.
Obviously I've spent the past few days bleeding the system, and even relocated my overflow to be sure this wasn't the issue.
I'm wondering if my new mishimoto dual pass oil cooler is a farce? There are no signs that the fluid is being forced to flow in a dual pass manor... (ie weld marks where a plate would be separating the chamber internally) I have a hunch that the fluid is just going straight from the inlet to the outlet of the cooler judging by the cool temperature on the outside of most of the cooler and the fact that the outlet temp seems to be about the same as the inlet temp.
So... Would a faulty oil cooler cause my symptoms? The oil cooler is all that has changed in this new vehicle. I had a smaller oil cooler in the G, but the entire thing was expelling heat. with this one the entire left side is hot, but the right side is ambient temp...
Is it air restriction? I am running the crash bar this time around. Any thoughts or ideas would help.
Here is the cooler I have. See how there are no weld marks like the one below it?
No, it's not common for them to fail or become stuck at 35k, but anything is possible, and because it's an easy part to replace and diagnose, I would eliminate that first.. To test, get the car up to operating temperature, and with the car running, feel both hoses(upper and lower). They should both be at similar temperatures and very warm to the touch. Another way, with the car still running. Squeeze the lower hose as if trying to flatten it. Upon releasing, you should 'feel' the surge of coolant running through as you release your grip.. A third way, with the car still running at operating temperature. Squeeze the lower hose. If it's very 'tight' and won't compress. That can also mean a stuck thermostat.
No, it's not common for them to fail or become stuck at 35k, but anything is possible, and because it's an easy part to replace and diagnose, I would eliminate that first.. To test, get the car up to operating temperature, and with the car running, feel both hoses(upper and lower). They should both be at similar temperatures and very warm to the touch. Another way, with the car still running. Squeeze the lower hose as if trying to flatten it. Upon releasing, you should 'feel' the surge of coolant running through as you release your grip.. A third way, with the car still running at operating temperature. Squeeze the lower hose. If it's very 'tight' and won't compress. That can also mean a stuck thermostat.
Thank you for the advice first off.
I actually have a spare on the second engine I have. Derp.
I can tell you right now that the top line was hot and the bottom line was cold last time I felt around. The top of the radiator was scalding at the time and the fans were on. Both lines were extremely firm and resisted flattening, I have a strong grip and they were not pinching any time soon. I will swap the thermostat after work.
I'm curious, does the thermostat control the fans or just coolant flow? I was under the impression that the thermostat was both a thermostat and a thermostatic switch; signaling the fans to kick on. Now I'm thinking the fans are triggered from the ECU/coolant temp sensor, so even though they are on coolant is not flowing thru the tstat/ radiator.
Not a problem, bro. And yeah, those symptoms lead me to believe that you're having a thermostat issue.
The thermostat controls coolant flow only. The fans are controlled by the ECU, and that decision is governed by the input the ECU receives by the coolant temperature sensor on the back of the engine. That sensor will ''tell'' the ECU to turn the fans on between 195 and 215 degrees, and will do so until the temperature drops to below that threshold.
I swapped the thermostat and I actually heard the fans kick off for once. I didn't get to really test it though, my overflow line is leaking which is probably adding to the problem. I'm getting a new one on Wednesday. Will update then.
the coolant is always between 200-210 Fahrenheit cruising or driving hard or just idling.
Isnt 205-ish normal??
Originally Posted by yosip1115
I'm wondering if my new mishimoto dual pass oil cooler is a farce? There are no signs that the fluid is being forced to flow in a dual pass manor... (ie weld marks where a plate would be separating the chamber internally) I have a hunch that the fluid is just going straight from the inlet to the outlet of the cooler judging by the cool temperature on the outside of most of the cooler and the fact that the outlet temp seems to be about the same as the inlet temp.
I would laugh my @$$ off ... although it wouldnt change my opinion of mishi bc I already think theyre a zero to start...my C&R is dual and weld marks are very apparent! Do investigate!!!
I would laugh my @$$ off ... although it wouldnt change my opinion of mishi bc I already think theyre a zero to start...my C&R is dual and weld marks are very apparent! Do investigate!!!
for some 205 is normal, but that would be in some high heat.
I've had a few of these vehicles, and always noted the radiator fans kicking on and off, not staying on constantly. That is what tells me something is up.
Regarding the oil cooler, I'm investigating a bit tomorrow night. I'm not 100% yet after feeling it yesterday again.
I swapped the thermostat and I actually heard the fans kick off for once. I didn't get to really test it though, my overflow line is leaking which is probably adding to the problem. I'm getting a new one on Wednesday. Will update then.
Good stuff.. And a leaking overflow line wouldn't add to this, but a blocked one will.
Have you tried going back to stock to use the process of elimination?
More air = more fuel
More fuel = more boom
More boom = more heat
But yea if you lose an oil cooler your oil will be hotter than when you had one.
I'm not sure that I'm about to rip my engine out again to to back to stock at this point, haha. And turbo cars are more fuel efficient than stock cars when you stay out of boost. They burn less fuel in those instances.
I'm fairly certain the problem is the surface finish on the lower seal inside the radiator cap cavity. I'm seeing it push fluid out of the overflow and if I squeeze the upper radiator hose it influences fluid motion in the overflow tank even though the upper and lower rad hoses are soft. This is with engine up to temp. I'll report back.
Oh yeah and the oil cooler is doing well, what I felt was heat transfer on the outside of the outlet hose from the inlet when the engine was really warm diagnosing cooling issues. The oil itself was cool from what I've been feeling. I'd like to verify one day with a gauge.
Edit:
Just fixed the surface finish but it's still acting the same with either cap.
Upper hose is warm and easy to flatten when car is running and hot
Lower hose is very cold and no longer hard to flatten when hot/running
heat works
Fans kick on and stay on, but car doesn't overheat
no rushing of fluid feeling when releasing hoses, but I have silicon hoses and they're sort of stiff so that could be why I don't feel the fluid.
System sucks water from overflow as it cools as it should
It's not normal for the fans to stay on at this ambient temp with this radiator, it's about 55 degrees out. I also think the hoses are too soft when at operating temp.
I would laugh my @$$ off ... although it wouldnt change my opinion of mishi bc I already think theyre a zero to start...my C&R is dual and weld marks are very apparent! Do investigate!!!
that would be a pretty bad oil cooler without a plate in the middle of the ports.
Shine a line in one port and see if you can see it from the other or even snake a zip tie or something to see if you can feel the barrier.
that would be a pretty bad oil cooler without a plate in the middle of the ports.
Shine a line in one port and see if you can see it from the other or even snake a zip tie or something to see if you can feel the barrier.
I'll definitely investigate this further one day and will post up about it, especially if I find a lack of flow diversion.
For the time being I just want to fix this coolant system issue so I can drive car I just dumped thousands into and spent 3 months straight working on after work 470 wheel hp!!!
I'm probably going to get into some sort of pressure testing this weekend
I took a sample by cracking a fitting on my oil cooler and draining some into a cup. The oil is a grayish brown and it's only 800 miles old and it's the good stuff, amsoil. It doesn't seem to have much to it when you rub it between your fingers. Thin, not slippery. Not like amsoil usually is... The milky color was just under the cap.
I also monitored coolant pressure when revving/idling but that actually held steady except a 1-2psi spike when I revved it. This is with a setup which eliminates the radiator cap's ability to vent. I figured a noticeable rise in pressure would be seen if exhaust/combustion gasses were entering the cooling system.
The coolant system does not leak at all at 15PSI for 10+ mins. But...
The coolant system doesn't build pressure on it's own though. It builds maybe 5psi idling even with the radiator fans on. I pumped it up to 5 psi cold, started it, and it did not build up any pressure as the engine warmed up for 3-5 minutes. Concerning...
I fill to the top, squeeze the hoses to work the bubbles out, fill expansion tank, idle it, crack bleeder. Air never stops coming out and it doesn't build much pressure. Can still squeeze hoses flat, unlike when I pumped it up to 15psi.
I figured the thermostat leak was it but now I'm thinking either boost in the other car got to it, or the stuck thermostat caused the engine to overheat without telling me on the gauge because the gauges are useless. It's not showing all of the signs of a head gasket which is odd though. I think that's just denial speaking...
10-09-2017, 05:46 AM
Swapped Bodies, Greddy TT Setup Now Runs Hot
470 wheel hp!!! 
