200 TDI overheat

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ER1C

Well-Known Member
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Cheshire
So it was running a little hot which it NEVER does.

Top and bottom hoses were hot which was odd but on a whim I popped out the thermostat and tested it, it didn't work. so I removed temporarily, and drove and it seemed better but still past midway on the temp gauge. I only drove a few miles.

I flushed the radiator and now I come to replace the thermostat after 3 days standing (i.e put one in) as soon as I released the bolts water pushed up from the engine for about 30 seconds.

So there is pressure in there somewhere, any ideas ?

Radiator is 5 years old.
 
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It sounds as though you might have a head gasket failure.

Are you able to run a pressure test on both the cylinders and the coolant? (Cylinders approx 350+ psi and around 25psi for the coolant)

Have you any discolouration in the oil to indicate a leak through?

It is possible that the hasket might have blown between a cyinder and the coolant hole, so you might not have any oil discolouration!

If you leaave the coolant filler cap off and then run the engine, you might get 'puffinf' back.

Hope this helps.
 
Thanks chap !.

No discolouration. Alas I was getting ready for a week camping :( So I have just backed it back into its hole and will do some further analysis following your suggestions. I did note the power steering felt odd when backing it back in so I will check that also I cant see how water pump/belt issues would cause the pressure :(

The odd thing is I am losing NO water and oil is fine.
 
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I checked the stat by popping it into boiling water.
Its taking a while to get a little too hot i.e 15-20 mins.

I originally towed a trailer about 20 miles which is why I thought it was the extra load but the same occurred on the same run without the trailer which is what started me pondering the issue.
 
For my sanity, I have taken off the pipe from the radiator to the stat (North of the waterpump) and the one from the waterpump to the expansion tank.i.e (south of the waterpump)...I don't understand why I would get pressure in one area of the coolant system only, there wasn't any pressure in the expansion tank ? Could this more indicate a blockage as I had the expansion tank lid off at the point in time when I had the pressure from under the stat.
 
The tdi engine is real cool running, I once fitted a new stat drove 12 miles to work and thought thats a little warm the new stat was u/s and didnt open, most engines would have been scrapped with that treatment, naturally I drove it 12 miles back home before swapping the stat!

Putting a stat into a cup of hot water isnt a good enough test, the water loses to much heat way to quickly, dangling it on a bit of wire in a kettle is much better, the cheap stats are wnak, waxstat is the make you need.
 
[QUOTE="lynall, post: 3800220Putting a stat into a cup of hot water isnt a good enough test, the water loses to much heat way to quickly, dangling it on a bit of wire in a kettle is much better, the cheap stats are wnak, waxstat is the make you need.[/QUOTE]
as I said it went into BOILING water.
 
Ah sorry I see where you wrote it now!

Strangely enough I was thrashing mine today and noticed under load its running at 92 degc which is 5/6 degc higher than normal, buy it was quite hot today, theres no viscous on mine and I was working it hard down the motorway for a few miles.
 
[update]
New Radiator, new thermostat, all is well........ Towing trailer tonight 12 miles in low box 60 bales, temp was fine..

Not sure how to end this one other than

Thermostat was definitely duff.
Radiator was definitely below par.
 
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