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EP3 Overheating/Coolant issue

B

blackbeast

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8
Hi, just bought myself an EP3 facelift, on the test drive and the long drive home there were no issues, the following morning managed to get 2 miles before the temp gauge shot up. Turned the heaters on full blast and nothing but cold air came out, turned the engine off as soon as I could and left it cool down before restarting and coasting it as much as possible home. I don't remember the rad fan coming on at any point. I don't have a code reader to hand, but no EML came up on the dash.

Car is now up on axle stands, oil cap and dipstick is clear of mayo, found a coolant leak on the weep hole on the rad (just below a yellow drain plug), the radiator has very recently been changed im guessing for a cheapy as apparently the last one (original?) was cracked, can't see any other coolant leaks, nothing in the footwells or waterpump area, obviously had to top up the rad to get the coolant level back up. Leaving the engine warm up today, the radiator is stone cold to the touch including the lower and upper radiator pipes.

Not sure what to do and what I need to replace!?! Firstly, why is the rad leaking from the weep hole? Could it be that this is the issue i.e the system isn't pressurising? Is the thermostat stuck closed?
 
Answering my own questions, the o-ring was knackered on the drain plug, will have to get a new one from somewhere? Removed the thermostat, tested it in a bowl of 100deg water and absolutely no movement whatsoever so will need to replace that. I might as well replace the temp sensor on the rad at the same time. Have to wait until Tuesday to order the parts, hopefully the main dealer in Swansea either has them in stock or can get them same day. Will see if that lot sorts it, otherwise the only things left are a knackered waterpump and/or headgasket :(
 
I have had coolant issues too so I know your pain. I had to have a new radiator, thermostat, fan switch, hoses and clamps in the end

Its unlikely to be the headgasket as they are pretty strong on these. A full compression test should reveal more.

A coolant leak on a K20 can come from the water pump yes - but its usually just the bearing.
 
Given that you've tested the thermostat and found it's not opening I think that'll be the main cause of your problems there. Plus get the leak in the rad sorted and I think you'll be back on the road.
 
Cheers guys. Checked the waterpump area and that's bone dry. Collecting a thermostat with new bolts tomorrow and got a selection of orings from halfrauds.

Out of interest, does the EP3 have a fanswitch in the rad and a temp sensor in the side of the head? The guy in the parts department quoted £88 for the sensor in the rad, if that's just a fan switch, that's a bloody expensive switch!
 
What typically happens is that when the thermostat sticks shut, the fans don't kick in. Replace that first and I'm willing to bet that once the whole system is up to temperature as normal the fan will kick in as you'd expect.

It's because the water in the radiator doesn't get hot enough, because it's trapped by the thermostat.
 
Krzys said:
What typically happens is that when the thermostat sticks shut, the fans don't kick in. Replace that first and I'm willing to bet that once the whole system is up to temperature as normal the fan will kick in as you'd expect.

It's because the water in the radiator doesn't get hot enough, because it's trapped by the thermostat.
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Everything now gets up to temperature nicely following the thermostat change, but the fan doesn't kick in at all. It isn't seized so looks like it's the fan switch at fault? Im loathed to pay £88 for a fan switch from Honda, ordered this one instead - https://japserviceparts.co.uk/produ...em/radiator-fan-switch-oem-made-in-japan.html
 
No, temp on the dash seems bang on, once up to temperature the needle hasn’t moved. Eps light does come on when sat stationary for a while. Don’t have my code reader to hand but I’m hoping it’s logging a code for the high temps due to the fan not coming on.
 
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When my rad went (and it went in a major way, dropping literally everything including part of the rad out the bottom) the temps climbed rapidly and the needle was very obviously way above the 2/5ths mark it normally sits at.

If temp on the dash rises to the standard mid-point and doesn't move then I'd leave it a fair while until the fan eventually kicks in. EPS light is electrical power steering, nothing to do with check-engine.
 
mike.h said:
When my rad went (and it went in a major way, dropping literally everything including part of the rad out the bottom) the temps climbed rapidly and the needle was very obviously way above the 2/5ths mark it normally sits at.

If temp on the dash rises to the standard mid-point and doesn't move then I'd leave it a fair while until the fan eventually kicks in. EPS light is electrical power steering, nothing to do with check-engine.
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Doh, what an idiot! I was running it with the front wheels off the ground, hope the EPS light is due to that!?!

Anyway, I gave it a good run out today, should definitely be enough to get the fan on even in these colder temps as after the run I left it sat there with an increased idle of 4k for a good few minutes. Temp gauge didn't fluctuate from the 2/5ths mark at any point.
 
blackbeast said:
Doh, what an idiot! I was running it with the front wheels off the ground, hope the EPS light is due to that!?!

Anyway, I gave it a good run out today, should definitely be enough to get the fan on even in these colder temps as after the run I left it sat there with an increased idle of 4k for a good few minutes. Temp gauge didn't fluctuate from the 2/5ths mark at any point.
Click to expand...

EPS shouldn't be affected by that I'd have thought. I'd get it checked either way (see what the code was).

As for the fan, leave it running until it does turn on (and it should, eventually). You should know whether it works or not to be safe, better to know when it's somewhere you have control over, rather than out in the middle of nowhere.
 
Just to put this to bed, replaced the fan switch, replaced the coolant with Honda coolant and the job is done. Fan now turns on as it should.

Read the engine codes and no codes were shown, which is good to know.
 
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