Overheating TDI 90 (ATL)

I wouldn't be too concerned about the EGR cooler. For a start it's manufactured from stainless steel and the exhaust pressure within it will be considerably less than that in the cylinder head, possibly less than the pressure on the (hot) water side.

RAB
 
So assuming that the mechanics have done a good job so far and I see no reason to think they haven't and that the water pump is working and that a diesel doesn't generally generate a lot of heat and the fan would never be running at motorway speeds, then I think it most likely that you have a head gasket problem. So that should be fairly easy to prove with the kits people have directed you towards so far, also any garage would normally have a tester for that. As a secondary check, is there any sign of water going into the oil, e.g. white goop on the underside of the oil filler cap?
 
Thanks all. I have measured the coolant expansion tank ‘hole’; it is 37mm
I will order a kit off eBay; the one recommended covers 35mm-41mm
 
Egr coolers can fail with exhaust gases pressuring the cooling system, without the engine overheating, no something i would dismiss in this situation
 
I have now ordered the head gasket test kit.

It may be worth mentioning that when I had the bonnet off, in good light, I could see traces of coolant (presumably sprayed) in various places around and beneath the expan

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I hope to get back in a day or two after using the test kit.

Thanks again, Andrew
 
Is your car vibrating when accelerating? Your engine/gearbox mount seems to almost be touching frame (not centered)?

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Howey said:
Egr coolers can fail with exhaust gases pressuring the cooling system, without the engine overheating, no something i would dismiss in this situation
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Caused by what?

RAB
 
It may be worth seeing if all the pink is just beneath the expansion vessel. My car had a leak from the coolant sensor on the back of the block and it was quite impressive how far it seemed to spray over the hoses and components of the car but when I cleaned and dried everything and ran the car up to temperature I managed to trace all the pink but up to the highest point.

In another car a coolant leak turned out to be a spring clip on a coolant hose which had snapped on the back face so it looked okay but once the coolant was up to pressure it skooshed out all over the thermostat housing. Took me ages to work out it was coming from the hose not the housing itself.

Good luck.


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Oh. And the relevance here is that I thought it was my expansion vessel leaking because there was pink on its waist - turns out I had just been a bit careless in my filling and the spill was dripping down from the edge of the cap - not leaking from there.


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Pinkythelabrat said:
It may be worth seeing if all the pink is just beneath the expansion vessel. My car had a leak from the coolant sensor on the back of the block and it was quite impressive how far it seemed to spray over the hoses and components of the car but when I cleaned and dried everything and ran the car up to temperature I managed to trace all the pink but up to the highest point.

In another car a coolant leak turned out to be a spring clip on a coolant hose which had snapped on the back face so it looked okay but once the coolant was up to pressure it skooshed out all over the thermostat housing. Took me ages to work out it was coming from the hose not the housing itself.

Good luck.


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Click to expand...
Thank you @Pinkythelabrat. When I took the photos yesterday afternoon the daylight was good: I saw the spray residue on the various bolts for the first time. They were all in the vicinity of the expansion tank, but then that’s where I think the issue is, so perhaps I’m biased.
I will try to clean the under-bonnet/engine-bay area today. It is unlikely I will get it dry but at least I would like to remove those pink splodges. I’m hoping tomorrow to visit my elderly mother who has off-road parking: I can then leave the engine running for a couple of hours with the bonnet off and see what happens.
I think the head gasket test kit should be with me by Saturday.

PS unfortunately @mrbroons hasn’t yet posted a YouTube about cleaning the engine-bay :(

PPS I’m going to trust this video by AutoGlym
 
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I didn’t wash my engine bay! Although Chrisfix has a good video about that...

I just gave it a rinse and a dry with some paper towel. Coolant being very pink is handy and dabbing at each area with a clean bit of white paper towel quickly showed the highest coolant (on the back of the engine block - right at the coolant sensor)


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The weather is fine this afternoon. I have given (parts of) the engine-bay a clean, and then gone for a drive, leaving the bonnet off, to my nearest TPS to buy a bottle of coolant. Despite the clean, using diluted traffic film remover and a brush, left to dwell for a few minutes, then thoroughly rinsed-off using a hosepipe, there are still traces of pink around the bolts beneath and around the coolant expansion tank.
I am hoping that new spray may be easier to spot.
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