Strange Problem With Tdi - Coolant

[neilb]

1.9 TDi engine. Had new rad and water pump and coolant thermostat. VAG shows no problems.

 

After about 40 mins of driving, particularly on Motorway or under load, oil temp gradually rises and coolant leeks out of the small hole at the base of the neck of the header tank.

 

Any ideas most welcome.

Edited November 11, 2009 by neilb

[jkspoff]

This post needs to be in the MkII section, anyway here goes, I had a similar problem and it turned out to be the header tank expansion cap not sealing properly, new cap improved the problem.

[RADIOTWO]

1.9 TDi engine. Had new rad and water pump and coolant thermostat. VAG shows no problems.

 

After about 40 mins of driving, particularly on Motorway or under load, oil temp gradually rises and coolant leeks out of the small hole at the base of the neck of the header tank.

 

Any ideas most welcome.

 

First question, why did you change Rad,Pump,and Thermostat ?

 

second question, are you getting water in the oil ?

 

Sounds to me as if it has over heated and warped the head(or alike) and pressurizing the water system !

 

Radiotwo

[neilb]

1.9 TDi engine. Had new rad and water pump and coolant thermostat. VAG shows no problems.

 

After about 40 mins of driving, particularly on Motorway or under load, oil temp gradually rises and coolant leeks out of the small hole at the base of the neck of the header tank.

 

Any ideas most welcome.

 

First question, why did you change Rad,Pump,and Thermostat ?

 

second question, are you getting water in the oil ?

 

Sounds to me as if it has over heated and warped the head(or alike) and pressurizing the water system !

 

Radiotwo

 

 

Hi

 

 

items changed because pump impeller was loose on spindle and radiator was blocked.

 

I have had a sniff test done on coolant, all OK. No suggestion of gasket leak.No sign of water in oil, no brown residue etc

Edited November 12, 2009 by neilb

[Saif Rehman]

I assume that the impeller was whole and not shattered leaving debris in the system or you could have an airlock in the coolant system. It has been known that the system does take a while to settle after a coolant change.

[neilb]

The impeller was complete, no broken bits.

 

This has been doing this for about 4 months now.

 

Strange that the engine temp is normal but the oil temp indicator goes up to about 110 deg and coolant pukes out the overflow.

 

A sniff test would rule out a gasket/head problem, would it not?

 

Thanks all

[big_kev]

Could be knackered head gasket and air leaking into the water system.

 

Is the water actually boiling hot or is it just warm ?

Edited November 12, 2009 by big_kev

[neilb]

The coolant is hot and the pipes to and from the header are hot to the touch.

 

How much would a gasket job be?

 

 

many thanks again

[randsy]

The coolant is hot and the pipes to and from the header are hot to the touch.

 

How much would a gasket job be?

 

 

many thanks again

 

make sure the aux water pump is working, its located behind the expansion bottle you should hear it buzzing after you switch the ignition off

[Saif Rehman]

Also check to see if the radiator is hot at the top and bottom - if not, the blockage is suspect.

[Willie Krashitt]

Hi,

Might be worth checking that the water hose going from the radiator to the thermostat on the front of the block hasn't delaminated and the inner layer isn't sucking in on itself. Had this occur on a Golf I once had with similar symptoms occurring when i was thrashing it. It looked perfect on the outside, but inside the pipe was another story.

 

Another point to check is whether the thermostat is in the correct way round - My understanding is that it is possible to do so. If it is, then it won't open as the 'bulb' will be in the cooler water coming from the radiator.

 

Hope that this helps,

 

George.