Coolant temp problem. Thermostat?

BakPak

BakPak

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Hello everyone,
I've been very lucky with my Audi, having read the nightmare problems that can and often do crop up.
On my way to work this morning at 05-00 so I had some warm air on tap (I have had warm air set on recent mornings), 18 degrees just to try and pretend it is summer. Anyway after 20 miles I see the coolant symbol flashing and the pointless / annoying bleeping going off and then I saw the temp gauge at 110 and the air coming in had gone cold.
I got to work and back home by driving like daisy, it was quite surreal being overtaken!
I think it's likely to be the thermostat?
Any thoughts please, Mark.
 
If your temp indicator went up to 110 and the heater blew out cold air I would imagine you've lost coolant somewhere... hence the coolant symbol on the dash check your level and look for leaks
 
Oh I should mention that for some insane reason I chose to fit a new header tank cap yesterday.
I assume the increased pressure has shown me where the leak is likely to be!
 
Or was the new cap not on correctly ? or not the right type ??.... if it was me I would refill and put the old cap back on and see how it goes ...don't know what K-seal is but if it's one of those addatives I would say no way... track down the the leak and fix it properly... must say though it all points to the new cap you added
 
if it keeps letting down like this you'll be buying another Toyota then soon lol
 
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I think it's the expansion tank. The overflow is weeping and with the engine turned off I can hear it hissing.
Ordered a new tank from ECP £14.
 
Sorted, for now at least! I think the pin hole leak in the rad might go soon.
I notice ECP do 2 rads at £60 & £95. The specs are the same, does anyone know where the price difference comes from?
WP 20150826 002
 
One is made in India and the other Hong Kong
 
Audi built a better car then a gt4 they built the rs4
 
Oh dear! Not fixed. Got home just after 300 mile round trip, mostly motorways putting my foot down blah blah. I don't hang about.
Checked the coolant and the level was just below min and I could see that coolant had been coming from the overflow port under the expansion tank. The hoses were firm but not rock hard.
I guess something is causing the system to over pressurize.
I have noticed some residue in the old expansion tank and it looks like flecks of copper, similar to copper grease.
 
The copper residue is probably from the K-Seal I put in two years ago to fix a pin hole leak in the rad.
I'm leaning towards a blocked system causing over pressuring and once the coolant has been forced out, then naturally over heating.
I'll try flushing the system first, can anyone recommend a method or product to do this effectively?
Also are the cheap radiators from ECP any good? TPS quoted me £140 for genuine where ECP £60 and £95.
 
BakPak said:
The copper residue is probably from the K-Seal I put in two years ago to fix a pin hole leak in the rad.
I'm leaning towards a blocked system causing over pressuring and once the coolant has been forced out, then naturally over heating.
I'll try flushing the system first, can anyone recommend a method or product to do this effectively?
Also are the cheap radiators from ECP any good? TPS quoted me £140 for genuine where ECP £60 and £95.
Click to expand...
Undo the bottom hose on your rad and run a hose at the top end that should get some of the crap out
 
Just done that mate, no crap came out that I noticed. Re-filled the system and ran it for ten minutes at 3000 rpm (brick on the accelerator). The temp quickly reached 90 degrees but even after ten minutes the hose coming from the thermostat is cold so now I'm going to change the thermostat.
 
I was just gonna say thermostat might not be working that would build up pressure if it didn't open
 
I hope it is that mate, I'll replace it this afternoon. Don't want the scary head gasket scenario!
 
john777w said:


Worth a look at this.............
Click to expand...

Lucky for me I know where the coolant is being lost (expansion bottle over flow).
It could be the head gasket causing the excess pressure but I don't think so, something else. I changed the thermostat earlier ....
 
Right fitted the new thermostat from ECP (£3) and after a bit of running the thermostat was definitely opening as the hose is now warm. The old thermostat was a genuine one from TPS and cost £20 from memory and was only a year old!
 
Still not sorted so left it with my local garage. I am suspecting head gasket, boo boo!
On the bright side I get to drive the Celica to work!
 
Right cars been looked at my local garage today. Thermostat checked and it opens, he also felt the water pump vanes and said he couldn't turn the pump. I had thought possibly the impeller wasn't being driven!
I'm now thinking fit a new radiator, in case it's blocked?
Would a blocked oil cooler cause problems?
At my wits end guys! As fun as Alicia is to drive, not suitable for commuting!
 
Hmmm didn't I say head gasket a few days ago ???
 
What I could really do with is some expert input from adams24. I wish his garage was around the corner!
If you read this Chris I'd appreciate your input. Thanks.
 
Well, I had the same scary (head gasket?) scenario and water loss a while back. Changed the cap and then the header tank and eventually found another culprit. That being the temp sender at the back of the engine - the O-ring had gone. That didn't cure it but the flange was then found to be cracked and changing that finally sorted it. There was also a likelihood that the system was air-locked at some point - this was all after a belt and pump change, with fresh coolant. Mine is a 2.0 FSI but I believe the diesels also suffer the same O-ring / flange problems.
 
Mike_B said:
Well, I had the same scary (head gasket?) scenario and water loss a while back. Changed the cap and then the header tank and eventually found another culprit. That being the temp sender at the back of the engine - the O-ring had gone. That didn't cure it but the flange was then found to be cracked and changing that finally sorted it. There was also a likelihood that the system was air-locked at some point - this was all after a belt and pump change, with fresh coolant. Mine is a 2.0 FSI but I believe the diesels also suffer the same O-ring / flange problems.
Click to expand...
Thanks for that Mike, I'll be investigating more this weekend. Mark.
 
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