Lately my car has been running warmer than i like, it doesn't get into the red but its been running hotter than normal. My temp guage (which i know isn't accurate) will hover above 210* id say anywhere from 215-220 which i know isn't normal because its never ran that hot before. A few months ago my gf and I took a trip to mt. rainier and it overheated on those curvy mountain roads-it ended up puking coolant out of the overflow tank. Well I talked to Ellis about the issue and told me to get a new cap, so i did and bled the air out of the system. All was good I thought as I took the same trip again and the temp never went about 210 on the guage. Well fast forward to July as I took the Advanced driving course at pacific raceways and the car got hotter than normal again but I was pushing it pretty hard so I figured maybe it was normal. But now I have the issue again where its hovering about that 210 mark. This is everything I've done so far to try and fix this problem

Tried bleeding more air from the system
Cleaned outside of condenser with a power washer
Pressure tested the cooling system (which is strange because it looks like it holds pressure good but if you look at the guage closely it very very slowly goes back down and im not sure if this is suppose to be normal, I tested the cap and its the exact same way.

So now i feel a little bit stumped, am i not getting all the air out? is this pressure test normal? or do I have a messed up head gasket? whats a good way to tell if the thermostat is opening up because im not a 100% sure if mines opening up all the way. I'll take the cap off start the car and let it get up to temp and the coolant just stays at the neck, its not flowing-sorry for the noob questions-but the cooling system just confuses me a little bit, ive never been good with understanding the whole system.

 

How were you pressure testing the system? Did you remove the cap and put a hand pump device with a guage on it? The system should be 15-17 lbs.

I would look at changing the rad cap. When your car is hot, pop the hood and watch the lower hose when you rev it a few times. If you see the lower hose colapsing, a bad cap might be your issue. You may also be missing the spring in the lower hose to keep from colapsing. They can rust out.

 

I just put a new cap on there a couple months ago, right after it overheated the first time, and yes thats how i tested the system.

 

If you start the car with the radiator cap off, after the car warms up and the thermostat opens, you will definately begin to see the coolant flowing through the radiator. On my car its a pretty dang strong stream.

You might have air in the system, the fix is to open the radiator cap, fill the radiator almost to the top. Start the car with the cap off, and let it get up to temp. After the t-stat opens, the water will start to flow and slowly start to rise. You should see air bubbles and steam working their way out. When the coolant reachs the top, put the cap back on. You know the t-stat has opened when the coolant bipass starts to squirt, it goes in right near the radiator cap. Make sure to use dex cool.

If you dont see the flow, it might be time for a new water pump.

If thats not the case, try the lower temp t-stat.

If that doesn't work, lower the temp at which your fans kick on, any tuning software can do this. You can play with the low and high fan speeds until you get it right.

I had some of the same issues, and I still can't get the dam overflow to hold the correct amount of water, but after replacing everything, it doesn't over heat anymore.

Hope this helps

 

I think,after checking the service manual, that the pressure should hold all day on that pressure test.After all,you might drive 8 hrs straight on a cross country trip and it's supposed to maintain 15-17lbs.No directions came with the tester?

 

I didnt check for directions, but I'm pretty sure you're suppose to do it on a cold engine right? will that affect you're test results much? I didnt have time to wait for the engine to cool all the way down. Also, I don't have Dexcool in the system anymore, I flushed it all out when I did the H/C on my engine. I also have it programmed to have the fans come on at 180 I believe, or at least lower than factory settings I know.

 

The pressue will rise in a closed system if the temperature increases and vice versa, so doing the test on a completely cold engine is important. If the coolant was still hot and you pumped up the system, as the coolant cooled, the pressure would slowly drop, not significantly, but would still drop. Try it again when the car has been sitting overnight.

 

that would make sense, but I think I fixed the problem, changed out the t-stat today and its running much cooler now. I think it was opening up too late or not all the way-this morning i let the engine get up to operating temp and then felt the upper rad. hose and it was still cold so I knew what was up. thanx for all your help guys.