2003 Cupra R overheating on idle, however fans kick in some of the time

[warond]

Good Evening,

After leaving the car on idle for around 20 minutes, I found that it started overheating.

The fans kicked in once, and the temperature stayed at about 90 (after going slightly over). After this, 5 minutes later, the temperature started to rise to about 110. After switching the engine off, I turned the ignition back on, and found the fans started to go after about a minute.

Now, I have taken the cap off of the coolant tank, and checked that water is squirting out of the top pipe, as I believe this is the test to see if the water pump is working. Water seems to be spraying out when I rev the engine.

I am hoping this is just a coolant temperature sensor (although I changed the previous one along with the thermostat about a year ago). Could this still be a water pump related issue? Are there anything other checks I should do, or is there another way to find the culprit?

I would like to add - the revs seem to fluctuate slightly - especially when the temperature reading starts increasing. The revs seem to increase and idle just under 1000 when the temperature is above 90.

As I say, the fans kick in the first time, and then after a further 5-10 minutes the temperature starts to creep up.

Any ideas?

Thanks in advance.

 

[Fmxvxx]

First check is coolant strength if you have a mix that is to weak the water will start to boil and not cool the engine.

Next plug the car in and read the codes if it is indeed a sensor it will register a fault code if it is failing.

Water pump may still be working but only partially, broken fins in the water pump could cause a lack of coolant circulation which would induce an overheat condition.

 

[mattyholmz89]

Slow speed fan issue would be first guess... very common problem there's a fix here. http://www.seatcupra.net/forums/showthread.php?t=331943 other than that it's about £400 (if it is slow speed fan) but follow what that says you'll find out =D

 

[mattyholmz89]

Mine does it still... I don't think it causes damage as it's not overheating excessively only to 105degrees then the fans kick in and drop it to 90 again I need to get it fixed but I barely let it idle for that long as I don't ever usually get in traffic

 

[warond]

Thanks for the replies.

I'll check all of those things. Ive had the car for a while now - I've never had any problem of overheating at all in the past. Usually the fans would kick in before the temperature rises over 90 - now they seem to kick in whenever they want.

When they do kick in, they are very loud and both activate, and continue to do so until the temperature is back at 90 degrees.

There is some water coming out of the top tube, however i'm not sure how much there is meant to be! Still possible to be a water pump then I guess, although i'm hoping its not!

Thanks

 

[mattyholmz89]

I don't think it is the pump if they only come on loud and fast I'm 99% it's the slow speed fan have a little read you can test it tells you how to on the link I posted

 

[AshBoy]

put your heater on high temp and it doesnt over heat lol i have same thing lol

 

[warond]

Hi Guys,

So i've just been sitting in my car for about 45 minutes with the car on. Checked the water pump - there is great flow.

The fans have kicked in 4 times over this period - the temperature needle has not moved from 90 degrees. I have also checked this on the climate control - it was reading 90 degrees the whole time.

What I have noticed is slightly fluctuating revs - sitting slightly higher than usual. The revs fall and drop slightly at around 800 RPM. I find that when restarting the car when hot, the revs sit at around 1,000 for a bit, before dropping slightly. I'm thinking faulty CTS? Will get it scanned tomorrow regardless.

I have turned on the heating and A/C - neither of which start rotating the fans. Seems as though I will need to fix the low speed fans using that website! - Thanks.

Either way, for some reason a session of idling for 45 minutes did not make it overheat - fans kicked in every time.

Thoughts?

Thanks!

 

[jt20vt]

I had a problem with the fans not kicking in a couple of years back. I changed the fans instead of doing the fan mod. I purchased the fans from ECP (Euro Car Parts) cost under £200 fitted them myself as its all plug and play. There is a thread on here somewhere with the part numbers listed.

 

[warond]

Thanks for all of the information guys.

I managed to fit the resistors over the weekend - £25 in parts, slow speed fans are now fixed!!

Hasn't fixed the slightly hunting idle though (only every so often). Not sure what this could be, got the car scanned however no fault codes came up.

 

[mattyholmz89]

Get it on vcds and monitor the idle mine dips between 760rpm and 720rpm every so often you can feel it in the car and the needle dips a little but I took injectors out and cleaned crap off the seals and that seems to have helped the idle a bit stil does it every now and again but not so often check out the injector seals bud... how long did it take you to fit them as I want to do it but usually break everything I touch =)

 

[warond]

Back again!

And the Cupra R is now stage 2.

However, the intermittent overheating is still present. Slow speed fans work when the A/C is on, and they also work 90% of the time on idle to stop the car rising above 90 degrees.

However, very occasionally the needle is able to creep up to around 110 before the slow speed fans kick in.

Any thoughts on why this would be? As I say, most of the time the temperature isn't able to get above 90 degrees before the fans activate, why would this sometimes not happen?

I think my secondary water pump isn't working as I can't hear it when I turn the car off.. could this have anything to do with intermittent overheating?

Thanks!

 

[Mark One]

I would fix your electric water pump very soon. I remember looking at the water route and I think it's the only thing providing water to the turbo. I doubt the flow through it will be great even when running.

I believe the coolant temp sensor has two sensors in it (4 pins). One for the dash and one for the ECU. If the ECU doesn't see the temperature it won't kick in the fans. Could check with any OBD diagnostic tool.

The final remaining thing is the relay box that controls the fans. This is a bit more than just a relay box really - it notices if ignition is turned off and won't run the fans at high speed, it also drives the electric water run pump and has a timer to control the after-run. Problems with these boxes are rare i think - but maybe worth a shot?