I have searched and searched and searched and cannot find anything to help. I have replaced thermostat, coolant temp sensor (ecu 2 prong), replaced the radiator cap, done a compression test to rule out headgasket, fan works properly and everything in between but the problem still continues. I recently did headstuds with the one-by-one method so I thought it might have been the headgasket but no. I have a mini radiator mod with a slimline and ran it all last summer with no problems whatsoever. At idle, temp gauge climbs to about 3/4. I don't have a coolant temp gauge so the stock one is what I'm going off of. While driving the temps go back down so it's mainly at idle. I just can't rule out anything else as to why the sudden change in temps. Any help would be greatly appreciated and I'm sorry if this is a repost but I can't find "the" thread anywhere.

 

Hmm are there any coolant leaks that you have seen? If you have replaced all of what you said, theres not much more to rule out, but the water pump. But if its not leaking id say dont worry about it then. I would do a pressure test on your coolant system just to see if anything pops up. Or the next time the temp rises when your sitting at idle, turn on the A/C and see if your temps go down. Both fans should cool it down, maybe the main fan is not doing its job too well. Good luck.

 

I haven't seen any leaks anywhere but then again, I haven't checked the water pump side yet. I will be doing a leakdown test as soon as a friend of mine gets some free time and we will hopefully find out the problem. If I had A/C I would but my condenser took a crap on me and now I'm waiting on a new one to come in the mail. With the mini radiator, there is only one fan for it.

 

Bump. Still having this problem... Replaced everything except for the water pump and head gasket. I did a coolant system pressure test today and I pressurized it to 17 psi. It held so I cranked it up and it stayed at 17 psi until the thermostat opened. Once it opened, it raised to about 20 psi. Slowly raising the rpms, it started dropping and eventually settled at around 15 psi. Gave it a few quick revs and it didn't jump up as if it were the cylinder pressure affecting the coolant. Also today I completely flushed the system and put in a brand new thermostat rather than my friends old one. It ran fine all day long but tonight I decided to do a quick pull and see if everything was still in check. It started to sputter as if the plugs were bad. I then checked the plugs (bpr7es gapped to .25) and the barbs were white as if it's running lean. AFR's are a contant 11.6 through the rpm range. If anyone knows anything please help out. I have a new head gasket, timing belt, balance shaft belt, and timing belt tensioner ready to go on. I just need to know what everyone else thinks...

 

Bump. Nothing at all? Come on people...

 

ttt. This must really be a hard subject for everyone...

 

Bump?

 

id buy a water pump if youre gonna be replacing the timing belt. that will rule that out at the same time.

 

Can I borrow $150 then? haha I just don't have the funds right now to buy anything else for it at this time. I can do the head gasket and timing belt, tensioner, and balance shaft belt but that's it for right now. Water pump will have to wait until after I get paid.

 

i just noticed that you are in pcola, lol. navy? ill be there in a month, but i wont be in an evo anymore . Ill be in an 04 cobra Id wait til next payday then, trust me, its worth the wait.

 

I am navy but Im stationed in Gulfport, MS. My family lives in Pcola. There's lots of cobras around so you'll make friends quick lol.

 

you may have a blown head gasket. also when you change your timing belt make sure you include the water pump as well.

 

Check your grounds. If the car does it at idle, it is most likely due to a bad ground, when the fans come on, and current is drawn, the stock gaige goes mad. Do a quick DIY ground from the neg battery pole to the same spot the fan grounds, near the driver side headlight. It can't hurt and may solve your problem.

 

I'll try that! Thanks man!