Overheating issues


nwr161282

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Jun 26, 2011
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119
I have tried to search but can't find any symptoms which match mine.

I have a ek9 engine in my civic Jordan rally car. On my last rally I had overheating issues. So during the rally we removed the thermostat (which did look a bit past it) but still it overheated. We then noticed the top hose from the radiator had collapsed. So we bled the system and this did seem to help a little for the last stage we did.

So after the rally I replaced the water pump the thermostat and the water temp sender.


Today I was at a track day to see if I had cured my problem but sadly not. After 3 laps the temp was on the rise then at end of 4th lap was nearly at top of the Gauge so I pulled in and bled the system again. Out we went but same issues again. So back in and I removed the new thermostat. Back out but same overheating again after 4 laps. So I then decided to try bypassing the heater matrix but still the result was the same. The coolant looks nice and clean and the fan does come on as its set with hondata. The radiator is a quite new.

Anyone able to help as I'm not sure what to try next.
 
Sorry I also for got to add that the temperature slowly returns to normal if I leave the car idling long enough.
 
Has it only had the overheating issue after the new radiator? Is the rad oem? Also does it overflow the expansion tank when it overheats?

Sounds like the coolant system could be air locking somewhere if the top hose is collapsing
 
Come to think on it yes it has only started doing this since I fitted the new radiator after a accident. No the rad is not oem. Yes some coolant does flow into the expansion tank.

Yes I kept thinking it was just an air lock but it no matter how much I try bleed it my problems are still there.
 
I'd say either the radiator is partially blocked internally causing the overheating once you've given the engine some beans on track, this also might be creating air pockets as the coolant circulates causing the air locking too

Or I've had a problem of overheating before on a previous car that was fine on light road driving but as soon as I gave it some stick on track it would overheat and boil it's coolant out of the expansion tank after just a couple of laps, this turned out to be the radiator cap being weak on the spring part and not quite sealing the radiator so it wouldn't hold the pressure as it got hot so was boiling the coolant,

Might be an idea to try another radiator if that's an easy option,
 
Yeah I think changing the radiator is gonna be my next port of call. I have a couple of old radiators I could try they have a few bumps and bruises so might try one then get it recored if I solve the issue.

I previously had the larger integra radiator with twin fans fitted but my tuner said he was struggling to get a high enough temp to set the car up so I swapped it for the standard smaller radiator. Anyone been told the larger radiator is keeping the car too cold?
 
cant say as ive ever heard that one before, if its running too cold then the thermostat is sticking open, new thermostat should regulate the flow to the rad keeping the engine running at desired temp on either half or full width rad, would only be an issue the opposite way if the rad cant keep the engine cool enough
 
Yeah I think I'll try the bigger radiator as at the moment I'd much rather have too much cooling than none at all.
 
Had one recently that the impeller had sheared off the water pump just another suggestion if the radiator doesn't cure it
 
Thanks but I fitted a new water pump last week and today was its first real drive in anger so I recon the pump is ok but will check.
 
It's looking like it was the radiator. Tonight I've fitted the larger integra twin fan radiator. Not mounted it but plumbed it up to test. I appears to be working better. The fans will kick in for a couple minutes then they go off. When I think back when the other rad was fitted the fan would come on and stay on it would not go off. I put this down to being something in the map.

Obviously I have not driven this in anger yet as I need to mount the larger rad but it looks like we might be heading in the right direction.

Thank you for all the words of advice.
 
Update

Was out on a small test today and it seems my car is still over heating but it's taken longer to over heat now the larger radiator is in.

Previously I was over heating after 5 mins of hard driving but now it's taking 20 - 30 mins before over heating.

So far I have fitted a new water pump, temperature sensor, thermostat and a larger radiator but still I have an issue.

On my first run today I turned off the radiator fan override so it was only the temp switch and not the Ecu telling the fan when to come on. After 15-20mins of hard driving up went the heat. So pulled in, reset the Ecu to override the temp switch at 199F and 30mph. This did seem to help as next time it took 30 mins before it started to over heat.

I have performed a leak down test and the results were good pressure only dropped to 95psi from starting pressure of 100psi.

I am now wondering if the head has a hair line crack in it and it opens up as the temperature goes up.

So think I'm gonna pull the head and fit another good head which I have unless anyone has any other ideas.
 
I once had an Boosted integra with similar issues. Fine at idle and cruising, but on track days and heavy highway pulls it would over heat. We found that reinstalling the lower "splash shield" allowed for better air flow through the radiator and not around/under it. This had a drastic improvement on cooling. So we went with if a little is good, more is better, and continued to build fins and ducts that helped concentrate the air flow where it needs to be. Never had the problem since on the 500 hp B18C. Since this started after the accident, was the lower splash shield reinstalled? My eye would be on what ever changed after the accident since that's when it all started.
The collapsed radiator hose is an odd one- I have seen a failed radiator cap do this- if you haven't already, a new OEM cap wouldn't be a bad idea. But I also believe blockage in the coolant passages can also cause this. Rare but possible.
If you remove the rad cap , can you see fluid flowing in the top portion? Especially when your play with the throttle? Should see flow.
Last thought would be to allow you car to get up to operating temp from stone cold, and monitor the temps of all the accessible coolant hoses. With out a thermostat they should all slowly , but equally get warmer until hot. If you find a below temp hose, then blockage would be suspected in that area.

Good luck, you'll find it.
 
I don't run with the splash guard as I have a sump guard fitted to protect under neath. I have never had an issue with over heating till after my accident. That's the head off its been heated a couple times so I guess no harm in changing it for another. Just gotta wait for a head gasket to arrive. Is there any way to test all the ports are clear?
 
As in the cooling ports? Perhaps with compressed air? Or the warm up cycle to see if you have hot and cold spots. Maby you popped the head gasket after the first overheating, and only shows it self when the engine get warm?
Do you have a single, or dual fan set up with the Integra radiator?
You mentioned your car ran cooler with the Hondata over riding the cooling fans at 199- correct me if I am wrong, but shouldn't the factory "Fan Switch" at the thermostat housing be turning on those fans by then anyways? I always thought the over ride was there in case the fan switch failed...
 
Hi guys, im new in this forum and i joined because i want to know mora about civics or honda related cars.

I have an issue with my cooling system and cant find the cause why my engine temp goes up(middle) when in trapik. Just recently bought new radiator,replace yhe thermoswitch and upper and lower rad hose. Just want to kow if its normal when the temp rise to middle when idling and goes back to normal when driving? Thanks
 
Sure the temperature will always rise when in traffic - right until the fan kicks in. The airflow needs to be there through the radiator for it to do much at all. The rise should be slow however, if it was shooting up that might suggest issues - low coolant level, stuck thermostat or a blown head gasket since i've not noticed bleeding problems on Civics generally.
 
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