B16AJDM

I can not for the life of me figure out why this thing is over heating, I have replaced the thermostat, checked the water pump(seemed to be fine), checked all coolant hosing for leaks, could it be a headgasket starting to go bad? Any other suggestions on what to check? and the fan does kick on.

cm8719500

Hey I have the same problem...

I have a b16a/turbo and I cant seem to find out why its over heating... I've tried everything..

It will ride good for a while and then the check engine light comes on..... after about 20 min of normal driving....

did you bleed your water system?

B16AJDM

Yes i bleed it several times several different ways too. And yes, mine starts to over heat after about 20min or 15miles of normally driving? It just makes no sense to me

slimjimming6688

check the radiator cap....

B16AJDM

I replaced it with and OEM one from the delearship because I thought that the system may not be building pressure because of a bad cap. But now its building pressure but still overheating.

slimjimming6688

leak test with a coolant leak tester. the one with the pump and pressure guage, look for a drop, and you might want to do this thing called a block test. tests for head gasket or blowby gasses in the coolant

nothing_shocking

it could be a clogged heater core or more likely the head gasket. try a leak down test, or if you can't get a tester, just do a compression test. if you get a low number in one cylinder, there's your problem.

B16AJDM

ok ima have to try that in the morning thanks for the help...ill post back with results

turbo97coupe

do a leak down test on the engine , and do a pressure test on the coolant system . one of those two test wll give you your answer if you have replaced all the parts you said and blead it good , this isnt on a boosted motor or any high performance build is it ?

raidacaipo

I just finished figuring out my problem similar to yours..
First take off your oem thermostat and put it in boiling water from the stove. You will see it slowly opening up. If it doesnt open up then its bad which means you need to get a new one.

Check to see if the fan is spinning. Remove the fan plug from the fan sensor and use a paper clip to jump the 2 pins. Then turn the car on the on position. It should turn on if it doesnt then you need to check your relay or the fuse under your interior dash labeled heater a/c relay. Its a 7.5 fuse.

Lastly if its still overheating, just make sure you bleed the system out correctly. If theres a bleeder bolt, untighten it and remove it. Fill it up with radiator fluid until you see fluid come out of the bleeder hole. After it comes out put the bleeder bolt back on and tighten. Then refill and follow the proper procedures by sliding your heater core all the way to the red. Then cap your radiator until its half tighten, not all the way. Then start the car for a bit.

Thats how I fixed my over heating problem.

B16AJDM

Turbo97coup: No, its not on a boosted motor and I have already pressure checked the coolant system.

raidacaipo: I'v already replaced the thermostate with an oem one so im sure thats not the problem, the fan kicks on when it should, and i did bleed the system properly. But im more then likely going to do it again tomorow but thanks for all the info.

raidacaipo

hrmm... that is very very strange... so your looking at the cluster and the meter is over H? have you check your radiator reserve tank when this happens? it should be shooting very hot radiator fluid back into your reservoir if it over heats. Are you able to touch the radiator hoses when it over heats? or is it too hot? is the top hotter than the bottom when it over heats? does your fan turn on when it over heats?

B16AJDM

The meter is goes inbetween half way and the H. The reserve tank is full when its happening and it is putting hot coolant back into the reserve. the upper hose gets way to hott to touch and the bottom one is fine and yes the fan does turn on...

shytdoode

bad waterpump? LOL

raidacaipo

Do you have an aftermarket radiator? if so the fan might be installed on backwards. Check to make sure its installed properly.

If your fan turns on then it should be cooling the coolant down... I would definitely look into the thermostat one more time new or not.. take a pan and boil water over your stove.. then put the thermostat in it while its boiling to see if it opens or not.. find some pliers to hold it with..

I purchased a motor and had the same problems as you.. I even tried installing a new thermostat but same thing keeps happening so I returned my recently purchase thermostat thinking that it wasnt the problem. So I took the old one and put it in boiling water. Then it start to open up slowly. I guess years of not driving must have made the thermostat stuck shut.. It only took some boiling water and time to reopen it. After I installed it back on it solved my problem.

Your reservoir is getting filled with hot coolant because your thermostat isnt working.. its not opening up to let the cool coolant get through and recycle the hot coolant to let the fan cool it off.. thats why your bottom hose is not as hot as the top.

B16AJDM

Ok, thanks for the info. I'm go check that right now.

supersteven

This actually happened on my buddy's turbo GSR with an aftermarket fan. We tried EVERYTHING then decided to do the paper test with the fan and lo and behold it was spinning backwards. We reversed the wires and now it doesn't get close to hot.