I haven’t checked for combustion gases, the aux pump is on the way, i ordered the wrong one first so that’s still coming.

 

Sounds like there's a way to check for a blown head gasket without pulling the heads (which is what I just did) to check for cracks as well....

 

Main thing is, am i not overheating? I don’t know what the deal is.

 

First things first, please watch this entire video:



It's a heartwarming compilation of kittens and puppies playing together. They're SO cute! Hopefully it will put you in a good mood and keep you from getting upset as we talk about your car.

Is your car overheating? Heck if any of us know!!! I'm a mechanic, not a psychic. We can't diagnose your car from a distance. You've got to do that. We've asked you to run some basic troubleshooting steps and report back. You really haven't done any of that, other than get an infrared thermometer. Even with that, you still haven't answered if any of those readings were taken at the thermostat housing. That's the only reading that matters.

I went out on a limb, extrapolating the tiny sliver of diagnostic information we do have. In your pics, the max value shown was 173F. Even if that was the thermostat housing (hint, hint, please specify), yet your dash gauge is pegged high, that's an indication problem. Is that the only problem? We do NOT know, as you haven't reported any other test results. But from Troubleshooting 101, fix the known the faults first before digging deeper elsewhere. You're probably looking at a new temperature sensor to fix the indication problem.

Besides this apparent indication issue, is your car actually overheating? You tell us! Correct me if I'm wrong, but I think the only physical sign you had of an actual overheat (not just an indication) was when your coolant cap spit out some coolant after shutdown. Yet your aux coolant pump was dead at the time, and one of its functions is to prevent overheating after the engine is shutdown. Everything is still hot, but there's no cooling action, so the coolant temps climbs for a little while. Could be that your coolant cap responded properly and vented this excess pressure due to the dead aux pump. We don't know! You have to run some tests and report back.

Some guys have suggested your car has a head gasket problem, or other issue letting combustion gasses into the cooling system. Heck if I know! If only there was a way to test for that...


No kittens or puppies, but still a good video. Note he's checking directly at the radiator neck, but on our cars, the only access is at the expansion tank, which will work just as well.

While you're at it, run a pressure test of the cooling system:



There, that should keep you busy for a while. In the meantime, maybe I should switch to decaf...

 

Okay bet, first of huge thank you for all of this , now the pressure test of the cooling system showed no signs of leaks , it held pressure, the temperature of the thermostat housing was 147°F and the temp of the head is 174°F. the line after the thermostat going to the radiator was around 130°. I should be getting the aux pump by next week, i think i’ve already said i ordered like two and they were the wrong ones. I think i have a leak at the pressure cap? I also have a slight leak on the Coolant resivour which really didn’t push in the test but i saw myself as coolant pushed through the seam of the coolant tank so my question would be can overheating be caused by a bad coolant resivour/cap? I really think my root cause is a bad ecm or bad wiring for the temp sensor but i’ll do a compression test and stuff starting next week, it just doesn’t look like combustion gasses getting in the cooling system, just don’t see it or have big signs of it. I put in a new temp sensor which changed nothing, i kept the old one with me, the new one shows the same reading and everything. Heat is hot, it was bled good. sometimes during the bleeding process the right charge cooler lines are colder than the left one, don’t know why. I’ve read and done up the bleeding procedures, if there is a better one, let me know. but i’m puzzled, just very confused. Compression test and another pressure test is next after i put the new aux water pump on. And we will go from there. But any suggestions based on the things so far?

 

If you have a leak it will show up in the pressure test!
If you have a leak, you will lose water and you will over heat.
If you cap is not good, you will leak water, and run a non pressurized cooling system, which at sea level will boil at 100 degrees, possibly causing the water pump to become inefficient, as it will try and pump gas, which it cannot!
If there is a leak on the expansion box, replace it immediately! And throw a good cap at it too.
The car is not worth risking for two silly leaks!

 

If you saw coolant escaping through a seam, just replace the tank. Don't mess around. It has failed. You have found a MAJOR fault.




Don't panic! I highly, highly doubt your computer is bad. With a leak from the coolant tank, the system was operating unpressurized. The cooling system has many passages all over the place. If the system won't hold pressure, coolant may not circulate properly everywhere. That could easily explain the temp reading.

Not sure how it held pressure with the tester, but maybe the seam somehow closed up well enough while cold. Regardless, replace that tank and see what happens.

 

Okay, huge thank you to both of y’all for this. I will be replacing the tank, anyone has a link or is it a better bet to just get from the dealership?

 

Part number for the expansion tank assembly is C2C41899.

 

we had a good run
i did the combustion test and it was a failure, so what’s next? i wanna fix the car

 

Well, that's not good. The only thing left I could suggest is to repeat the test on another car, just in case the test fluid was somehow contaminated and giving a false failure, or something like that. I doubt it, but it would only take a few minutes to be sure.

After that, you're probably looking at a head gasket. No guarantees, as you could also have a crack somewhere, but a head gasket is the more likely culprit.

 

Pull the plugs. Look for a plug or pair of plugs that are different than the others. Either white or off colored. Do a compression test. Post results.

 

+1 on removing the coil units and spark plugs to see their condition.

You won't really know the exact cause of the condition until the heads are removed and inspected for warpage along with the cylinder block. If the block is warped, the most cost effective method if you want to fix the vehicle is to find a used engine from a reputable supplier.

 

compression test is showing 90psi on all cylinders. car runs good and strong. i did the test for combustion gas again and found the color to not change. the first time i did it was wrong. i sucked coolant in and it read it bad.

 

If your compression test shows only 90 psi, you may want to try using a different tester as that's a very low reading.

 

I was wondering about the low readings, but would the presence of the supercharger skew the readings, perhaps giving misleading values? For a cranking compression test, the RPM is going to be lower than normal idle speed. That means the supercharger isn't up to normal speed, so perhaps it's causing an artificially low readings? I don't really know, as I've never run a compression test on a supercharged engine. Just thinking out loud...

 

That's great that you've run the test again, and found why it had previously given a bad indication. Good troubleshooting to go back and repeat stuff like that.

Now that you have replaced the coolant reservoir (and the aux coolant pump?), is the engine still overheating? Other than the seemingly low compression results (see my previous post, perhaps normal?), maybe everything is fixed now?

 

90 psi is way too low. was the engine cold or warm? How many cranks? Should go till it maxes- a few seconds. Warm engine. It shouldnt matter with the supercharger.

 

engine was cold, had oil down spark plug wells and smell like gasoline even though i cut off fuel. i found out the resivour cap is bad i ordered a new resivour. maybe that solves the issue. now just waiting

 

Agreed, but I think at this point, it would be best to put that on the back burner. There are so many variables with a cranking compression test, such as starter speed, throttle position, etc. Because of these variables, I was taught to never condemn an engine based solely on a cranking compression test.

For all we know, the test gauge could be defective, or it's not making a good seal at the spark plug hole. Maybe the starter speed is too low due to a rundown battery. Lots of possibilities. Rather than getting sidetracked trying to figure out why, I'd be inclined to replace the defective reservoir cap, fill and bleed the cooling system, and see what happens. If the problem continues, then sure, it's time to investigate further. But with any luck, the problem is already resolved. Remember my personal motto...