B18c running hot

[ringo]

Hi all,

I'm having some cooling issues with my EK which we recently swapped a B18c into. It's a bit long, but I wanted to include all details.

If I show it some brief VTEC love (1st through 3rd gear), the temp guage will rise quite quickly above normal. I can keep it under control by putting the heater on full (comes back down to normal eventually). It does the same thing during highway driving (100km/h) in 5th gear, but it doesn't do it so much during city driving.

When it gets hot, I pull over and notice that the bottom hose is cold (so thermostat is closed) and the fan is not on. The bottom hose is also hard to press, like its full of air. So I replaced the thermostat, but it didn't fix it. Then I thought maybe it was just a dodgy signal from the ECT sender. I swapped that with my old D series one, but it does the same thing.

I fitted an EK9 cluster with the swap (about 5000km ago), so I put my old cxi cluster back in, thinking the gauge itself was possibly shot. Again, no joy.

Here are some other relevant details:

Radiator - brand new aluminium twin core job - doesn't leak, not blocked, with new CPC cap. The radiator gets plenty of fresh air too (not obstructed at all).
Water pump - brand new Honda pump
Thermostat - replaced. The thermostat does open up eventually
Fan switch - turns itself on and off
Cooling system - no leaks. Have flushed several times (twice with a trade strength flush). Water flows in and out through the head. Have tried bleeding several times.
No ECU codes
No milky oil

Does anyone have any ideas? I'd really appreciate anything, coz I'm all out. My next step is to get a water temp gauge, which should tell me if I actually have a problem, or if the car is playing tricks on me.

Thanks for listening.

Joel

[Super-DA9]

What sort of coolant are you running?

[ringo]

None right now, I gave up using coolant. Flushing $38 bottles of Redline Water Wetter gets expensive. I won't be running coolant until it's sorted out.

Cheers

[Super-DA9]

haha i know EXACTLY what you mean. I'm trying to fix these bloody leaks in my cooling system and every time I gotta buy a whole 5L of performance 100 coolant, fkn expensive, annoying and repetitive ay?

what about the raiator? is it a full size like what the DC2 runs, or a half size? because I rememeber someone on the forums here was having overheating issues with his integra because the radiatior was too small.

just brainstorming here :P

[bennjamin]

if the bottom hose is cold- there is no coolant circluating from the thermostat and to the radiator. The thermostat opens automatically when it reaches a certain tempreture - in no way linked to anything electrical in the car. There is a chance you have replaced it with another dodgy one ? The size of a radiator , within reason - should no way alter how cool a engine is kept. The thermostat opens when it needs to , which when it does the thermo fan goes on as well as it circulates coolant thru the radiator and back into the head.If the radiator is slightly smaller then this happens more often. bigger it happens less often etc

[ringo]

Super-DA9 - radiator is half size, but dual core, so it should be good enough. That's what EK4s run anyways.

Bennjamin - I understand. The way I see it is either (a) you're right, and it's a mechanical fault (e.g thermostat), or (b) there is no problem at all, but my gauge is trying to trick me. It's unlikely that it is the thermostat, since it's the second brand new one. I can't rule it out though. But that doesn't explain why the fan isn't on. The bottom hose eventually gets warm, and the fan cuts in soon after.

Thanks for both your help.

Joel

[bennjamin]

couple of things - have you bleed all air from the system ? And , are you using the correct radiator cap ? (correct psi) ?

[ringo]

These are 2 things I'm unsure of. I've have 'tried' bleeding the system several times, following the procedure in my DC2 manual: fill 'er up, crack bleed bolt until steady stream of water comes out, cap at half mast etc. Are there any special tricks here?

The cap I'm running is a CPC 560-90 13psi. I just checked the DC2 radiator, and that has a 16psi cap I believe. I pretty much just matched up a cap to the radiator, since the one is came with was rubbish, and that was the closest I could find.

[Glocker]

take cap off, start engine, turn on heater on full blast, then wait for the fan to come on at least TWICE before putting radiator cap on. this will flush away the bubbles in your system.

[string]

Surely the bottom hose being cold simply means that the radiator is just doing it's job properly? You did say that it's a fancy aluminium job and that you've tried a couple of thermostats. The coolant flows from the head, to the top of the radiator, then out through the lower hose after being cooled.

If you want to know for sure, take out your thermostat. It'll take ages to heat up but you'll quickly find out whether or not you have a far more serious problem. I hope that you don't have what happened to me a long time ago: a cracked sleeve which leaked combustion gasses into the cooling system and heated it up like crazy.

[ringo]

Yeah, fingers crossed. Actually I think the thermostat lets water out of the motor (not in), so water flows from the radiator to the head, then back out through the t/stat and through the bottom hose.

I must confess, the radiator is a cheap ebay one

Cheers

[Bludger]

coolant flows into the radiator via top hose and out via bottom.