Engine Overheating Options

[Araykhel]

I have an ST204 that just crossed over 107k miles and I'm having some overheating issues after the car has had about twenty minutes of drive on it. When my car is driving at normal speeds my indicated temperature usually sits at half, great and normal . But once I let off the gas and decelerate the temperature climbs in no time. I find that idling is the worst and my temperature sits just below the red line when I do so.

I've used the great and nifty search feature to educate myself on all the issues to check/ possible fixes however I still have some questions. The first thing I want to check/ replace is my thermostat however I tried searching for a how-to assuming it wouldn't be a simple swap and found none. Do I need to drain fluids ( ) to do so?

[Araykhel]

the thermostat would be a good place to start. It would be advisable to change the coolant once you are there. If you don't drain the coolant before you start, a lot of it will come out when changing the thermostat. It's pretty easy to change the thermostat.

Find the lower radiator hose, and follow it to where it connects to the engine. Remove the hose from that end. Then, there are 2 10mm(i think) bolts that need to be removed and will lead right to the thermostat. Make note of the direction the thermostat sits. Change the gasket while in there as well!!

When putting the thermostat back, find the "jiggle valve" or "v notch" on the thermostat. Most come with a v-notch unless you get OEM. Hold the thermostat up to the light, and you will see the v notch. It MUST be aligned with the protrusion on the little metal neck!!!! Then put it all back together, refill with coolant, and you're done!! Make sure it is not overheating anymore.

Awesome, love 6GC and these kind of responses. Tackling the issue today after a nice meal and a cool head I drove her a few miles to warm up and took a look under the hood. Read this message literally after I found what I thought was the thermostat but when I first checked on the opposite side of the engine I found a valve that clearly needs to be replaced. Was hoping you could help me identify it.




Back on track, there was literally a minimal amount of coolant left. Soooo a quick fill-up later while running the engine things started to look a lot more amazing. The fan actually engaged after the new coolant was added and the engine temperature stayed at the cool middle.

I really hope for your sake it's not the case but...I bought and put in an engine last year and started having the same problem soon after. The first thing I was told to do after asking about it was let it sit idle for a while and check to make sure the radiator fans are kicking in when the temp starts to rise ( I guess you could check this also). What it ended up being was a small crack in the block( we thought it was a blown headgasket at first, until I dumped a few hundred into fixing it only to have the same problem). Basically what my mechanic told me was, when I was driving it's shooting coolant into the engine and keeping it around normal, when you idle, it stops and the temp starts to rise because it's not getting any coolant. It did this for a few days before I noticed any smoke. Once you see smoke it's definite. I had to replace it right after I tried letting it idle to check the fans because doing that allowed it to get hotter and hotter and expanded the crack. When I drove it next the temp immediately shot up and smoke billowed out. good luck man.

This is exactly what I am facing now, this car has been mine for 6K miles out of her 107K, so I can assume that the previous owner was an idiot or that I have an internal leak. Lets hope...