Honda Civic 1.6 Turbo Random Overheating

[Ahmadi6490]

Bought a 98 civic 1.6 a few weeks ago. Noticed the other day the temp went rising almost to the redline and I shut the ignition off to let it cool. This has been happening at random...I can drive 50 miles and it'll stay at operating temp and next thing you know it starts rising after another 50 miles. Coolant is topped off and i'm not losing any fluid. I can't figure out what might be the culprit.

 

With buying the car the previous owner gave me it's service records. At 111,000 miles the car had a new head gasket set, waterpump, radiator hoses, coolant flush, and the head machined. It currentally has 123,000 miles on it so I ruled out the waterpump and head gasket leaking. I also checked the radiator and all the internal fins are clean with no gunk or corrosion...coolant jug was clean it just had a few very very tiny specs of oil floating on top of the coolant prob from when they changed the waterpump 10k miles ago. Previous owner said it got hot and he replaced the thermostat as well.

 

I'm thinking it's air in the system that needs bled out, a faulty wire to the fan or a faulty fan sensor. Haven't checked if the fan kicks on yet because I have a hard time getting it to act up when I want it too...most of the time it does not overheat. Any ideas, thoughts, or suggestions?

 

 

Thanks for your help much appreciated. Btw it has a greddy turbo, front mount intercooler, and running on 7psi low setting.

[Not Brian]

Dumb question but is the coolant 50/50 with water

[greg1647545532]

When it overheats is there coolant/steam coming out of anywhere? Overflow or radiator cap?

 

Could be air, could be the thermostat, could be the head gasket. Turbo d-series can have problems with the heads lifting. Stock head studs? Try the simple stuff and if it doesn't fix it I'd pull the head and check everything out. May just need a new HG and a proper torqueing.

[Comebackkid]

I would replace the t-stat and maybe a new radiator cap. Also when the car starts to heat up feel the radiator to see if the whole thing is hot and no cold spots.

[stangsn95gt]

Agree with t-stat

[Ahmadi6490]

Thanks for all the input. It overheated today and I happened to be close to my buddy's shop who is a honda fan. We bleed the air from the system and the temps started going down! The fan was kicking in and all but the bottom coolant hose was not getting hot at all. It hasen't overheated since...his hypthosis was that there was a shit load of air in the system. The bottom hose now gets hot like it's suppose to and he said if it does it again were going to have to check the block. But after 10 miles on hard driving and excessive ideling it stayed at operating temp.

 

Sooo hopefully there was just a lot of air...i'll keep you guys posted thanks again. Cap and t stat have been replaced recently as well

[Comebackkid]

I would get a rad cap with the pressure release. Just if it overheats again just release the lever.

[Ahmadi6490]

Good idea anyone know where I can get one?

[Comebackkid]

Any autozone should have them

[TurboGoKart]

I would fix the problem instead of putting a band-aid on it.

 

 

You did the right thing by bleeding the air. That was my first suggestion. I usually start with the cheapest first if I'm unsure, but usually you can pinpoint what the problem is. What radiator do you have in there now? Stock single core? Or the Del Sol half size (width), but still dual core?

[Ahmadi6490]

Drove it all day and no problems temps were below halfway. On my was home at night it heated up to a tad over halfway and then proceeded to a quarter way above....I heard the fans kick on and it slowly dropped to staying just above the halfway mark. Weird.

 

Yeah i'd like to fix the problem myself because I don't trust band-aids for very long lol. I think it's the stock single core radiator. I was thinking of getting an aftermarket fan and/or radiator if the turbo setup is producing too much unwanted heat? I don't know much about turbos but maybe the stock cooling system isn't good enough?

[Miller]

From the behavior of the spike up than dropping down you almost certainly have airbubbles. Top it off again.

[TurboGoKart]

Yeah. I would re-bleed again. I also had problems with my stock single core and it starting to overheat a little. I switched to just the dual core 94-97 Del Sol radiator, and it fixed it. So if you were to go to an aftermarket thick racing style radiator you'd be supa fine lol. Stock radiator on a turbo D-series is a bit small.

[Das Borgen]

thermostat and radiator cap

if problem persists, time for a new headgasket and machining of the head

[Ahmadi6490]

Yeah i'm thinkin more air bubbles...where's the bleeder valve located on these things? i tired looking but couldn't find it. I'll most likely go with the dual core del sol radiator...those aftermarket ones are $200 lol.

 

Head was machined 10k ago I hope I don't have to do it again.

[greg1647545532]

I think you're being overly optimistic about the condition of the head gasket.

[Ahmadi6490]

Only because it was replaced last year and they charged $1700 to do it

 

Thanks for the help guys...i'll start lookin around for the dual core radiators.

[Browning]

t/stat

air bubble

head gasket

[mjrsplat]

A simple compression test would tell if the head gasket needs replaced. I'd check the compression.

[Das Borgen]

A simple compression test would tell if the head gasket needs replaced. I'd check the compression.

compression test won t tell you of a bad headgasket.........it can however tell you if you have bad valve seals or burnt valves or bad piston rings

 

a compression leakdown will tell you if you have a bad HG

[DaddyBuiltRacing]

Bad tune could cause over heating issues, too much taken off the head could throw the timing off and cause overheating. Like Scott said single core radiator could also be the issue (ebay $40 dollar radiators work just fine)

 

Overheating issues suck ass since there is usually about 10 things that could be the issue lol.

[Ahmadi6490]

I'm gunna try and bleed the air out one more time. Would a spike in the temp like I described be a head gasket problem? What Miller said makes really good sense to me. I would think if the HG was bad it would just heat up and stay like that instead of dropping and rising?

 

If it overheats again after I bleed it out i'm gunna get a compression leakdown test over the weekend. I'll keep my eye out for a larger ccm radiator too. Maybe if I swap radiators it'll bring the overall temp down. Overheating sucks lol what a headache...could be worse I suppose...thanks again guys

[Ahmadi6490]

Bad tune could cause over heating issues, too much taken off the head could throw the timing off and cause overheating. Like Scott said single core radiator could also be the issue (ebay $40 dollar radiators work just fine)

 

Overheating issues suck ass since there is usually about 10 things that could be the issue lol.

 

Ebay FTW i'm gunna buy one asap

[DaddyBuiltRacing]

I used an ebay radiator on a turbo b20 and didn't have any issues. I have a C&R in my car right now which is like 4-5 times the price of a ebay one and I don't see any difference to be honest, only reason I have the C&R is because I got it cheap.

[TurboGoKart]

Screw the stock Honda bleeder screws. They're a bunch of shit. Not even located at the top of the coolant system. Warm the car up to operating temp. CAREFULLY and with a rag, take the radiator cap off. Start squeezing the upper and lower radiator hoses. Sometimes the bubbles will get 'stuck' in those hoses, and it also helps to move the fluid around. Keep doing this and topping it off when it sucks the coolant back in. Repeat, repeat, repeat. With a stock single core radiator, there's seriously not that much coolant in that motor/hoses/radiator.

 

I ran one of those eGay knockoff racing radiators in my built D16. Even at 24psi, I had no issues with cooling.