OK so a little while ago my car started overheating at idle, going back to normal when I give it gas. I checked my coolant overflow tank and there was some oil spots in it. hmmmmm. I let someone else drive it and there's a little bit of white smoke comming from the exhaust. It's a turbo D, so I'm thinking what you're thinking. Head lifting. So I got a new OEM head gasket in and arp head studs. Flushed and filled coolant.

So a couple days go by and everything is going good, no oil in coolant, no smoke, but it overheated a couple times again. WTF. So I let it run for a couple minutes at idle and felt upper hose, HOT, lower hose was warm. Ah hah, thermostat is stuck closed. Quick fix. I get a new one and throw it in. Next day going to work at drive thru, car overheated slightly again. Dammit. What the hell could it be. It only does it at idle. Fans are comming on but only for a couple seconds. What could be causeing that? What should I replace/look at???? I didn't think it was fan switch or relay, cause the fan's still comming on, but only for a short period. Well any help would be awesome.

 

my eg would get hot some times because the fan would not come on long enough so i just wired it to a switch and i havent had a problem since

 

That's fine. But I wanna fix it, not rig it

 

it could be your fan relay but im really not sure

 

if the fan relay was stuck or bad, wouldn't it not work at all, or be constantly on?

 

anybody?

 

What Year ?

 

it's a 99 d16y8 turbo. My coolant level is good. Only overheats sometimes at idle

 

Have you tried replacing your coolant temp snsr?

 

thermostat or the radiator..?

 

Air bubbles in your coolent lines will make your fan not come on. Try running a lower rating thermostat like 180 instead of the 190. Coolent leaks? Oil in the coolent would be blown headgasket. Any coolent in oil? Try checking the fan relay. Since your boosted, hook up the fan to a switch and keep it on all the time. It's great when cooling off the engine after a sprited run. Leave the fan on for a an extra 5min or something.

 

what kind of thermostat are you using? cause that will play a big roll in your temperature. here is some info on Thermostats.

Ok ive had several problems with my car overheating so i decided to do a test on thermostats. all thermostats where tested individually starting out with cold tap water. thermostat was hung from a wooden spoon into boiling water. used a digital thermometer to see when the thermostat was full open. hope it helps some of you
I went and bought a thermostat from the following stores
1. advanced auto
2. napa
3. auto zone
4. pep boys
5 Honda
and the results were
1.the advanced auto one was rated at 180 degree's i did a test on it and it did not open til 211 degrees. so that went back in the box $ 8.79

2. Napa rated at 160 opened up at 185 $ 9.35

3 auto zone rated at 180 and opened at 190 $6.45

4 pep boys rated at 160 and opened at 171 and the 2nd time around it didnt open til 197( it was sticking 7.84

5 honda it was rated at 178 and opened at 176. $18.92.

So its true u get what you payed for. the honda has been in for 3 days and i have yet to turn on my fan

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDMlyfestyle &raquo;</TD></TR><TR><TD CLASS="quote">what kind of thermostat are you using? cause that will play a big roll in your temperature. here is some info on Thermostats.

Ok ive had several problems with my car overheating so i decided to do a test on thermostats. all thermostats where tested individually starting out with cold tap water. thermostat was hung from a wooden spoon into boiling water. used a digital thermometer to see when the thermostat was full open. hope it helps some of you
I went and bought a thermostat from the following stores
1. advanced auto
2. napa
3. auto zone
4. pep boys
5 Honda
and the results were
1.the advanced auto one was rated at 180 degree's i did a test on it and it did not open til 211 degrees. so that went back in the box $ 8.79

2. Napa rated at 160 opened up at 185 $ 9.35

3 auto zone rated at 180 and opened at 190 $6.45

4 pep boys rated at 160 and opened at 171 and the 2nd time around it didnt open til 197( it was sticking 7.84

5 honda it was rated at 178 and opened at 176. $18.92.

So its true u get what you payed for. the honda has been in for 3 days and i have yet to turn on my fan
</TD></TR></TABLE>

Good info, but one thing. The rating can be for different points. Some rate when it starts to open and some fully open. A thermostat for civics is suppost to start opening at around 170-180 and be fully open at 190. I have one rated at 180 and it runs no cooler then the 190 rated honda one. Also remember that a thermostat also operates on pressure from the cooling system aswell.

 

well it's not the head gasket as someone asked. That's brand new with arp's. the thermostat is a 170. I don't think that's a prob cause that's new too. I guess I'll change the thermo switch. Does that seem to be the way to go? Coolant was bled IAW helms, so I don't think that's an issue.

 

what kind of thermostat is it?

 

it's from autozone, but it's rated at 170, not 180

 

autozone thermostats are complete ****! sorry to say. but OEM ones are the best.

 

yeah that's what I figured, but this one works better than my old OEM one and I don't have time to wait for one to be shipped

 

bro str8 up if ur car is overheating ur fan should remain on if the fan is not stayin on then thats ur problem right there stop looking for anything else

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Slammed92hbonN20 &raquo;</TD></TR><TR><TD CLASS="quote">bro str8 up if ur car is overheating ur fan should remain on if the fan is not stayin on then thats ur problem right there stop looking for anything else </TD></TR></TABLE>

I agree, sounds like the thermostat is doing it's job just fine. You only overheat at idle right? If so check your fan's electrical connections, relay, etc. I think it is why you are over heating.

 

If you are overheating ONLY at idle, then that means you are not getting enough air-flow at idle. This would point to the radiator fan not turning on or not staying on long enough. If you dont want to rig up a switch then spend the time to figure out why it's not coming on and fix it.

Open your hood with the car in idle and SEE if the radiator fan kicks on. It takes all of 5 minutes and that will tell you if the fan is the problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hatchy-Ownzjo0 &raquo;</TD></TR><TR><TD CLASS="quote">If you are overheating ONLY at idle, then that means you are not getting enough air-flow at idle. This would point to the radiator fan not turning on or not staying on long enough. If you dont want to rig up a switch then spend the time to figure out why it's not coming on and fix it.

Open your hood with the car in idle and SEE if the radiator fan kicks on. It takes all of 5 minutes and that will tell you if the fan is the problem.</TD></TR></TABLE>

Agreed. Also, if you turn your AC on the radiator fan should automatically come on, so check that. Overheating at idle or in traffic is a huge problem for turbo cars because you have a huge source of heat soaking the **** out of the radiator and - I'm willing to bet - you're using the dinky stock unit that barely has enough cooling capacity to keep the bone-OEM powerplant from kerploding.

Ideas? Make a heat shield, hard-wire your fan to a switch (nothing ghetto about a car that doesn't overheat) or get a bigger radiator.

 

and if you need info on a bigger radiator, and want to keep it stock, the del sol radiator is 1in thick instead of .5 i think for all civics, when i boost my d, im going to try to use an integra radiator........fluidyne or koyo, hell maybe ebay with like 2in. thickness, and make brackets so i can put the rad at a slight slant, so it doesnt get obstructed with the turbo/t manifold

 

OK I went out to car this morning and let it heat up to temp. Kicked on A/C and only the heater core fan turned on. The radiator fan was off. So I swapped relays and still the same thing. So I tried to get the radiator fan to come on. It kicked on, spun around once, then turned off. HMMMMM. A couple more minutes went by and it came on again, only this time it stayed on for like 15 seconds then turned back off. So it's not the relay, what else could it be. Would the thermo switch have anything to do with it not turning on when the A/C is on. I really need some help here guys cause I'm sick of overheating. I'm getting a new radiator soon, but I wanna fix this fan thing 1st. There anything else I can check besides the thermo switch?

 

God, I have just been through this. You have the same symptoms as I did.

You may want to search through old post. I did a writeup on this.

Just a summary though. Did you do a leak down test? This was my sure tale sign I had a head gasket leak. Did you have a head shop check the head before puttting it back on? Just because you put in a new head gasket doesnt mean it will fix it. I had mine milled straight and true. Before I mounted the head, I made sure the block was straight and true as well.

Before I replaced my head gasket though, I replaced most components which included a new and better radiator, and fan switch ($30 not connected to radiator).

I havent had a problem since. Oh, make sure you put the timing belt on correctly or you will have sh__tty performance and you idle will be horrible. Dont forget to align the camshaft with the oil mark on the block, not just the crankshaft "up".

Good luck.