Hi all, 

 

A few eagle eye'd posters may have noticed that I had started a thread about a leaking tandem pump gasket a few weeks back....That was fixed and has been fine....

 

A few days after i sorted the leak, some more oil started appearing ontop of the gearbox and dripping down onto the drive. This time is almost looked like a watery oil.

 

Anyway, I took the airbox and housing out of the car and managed to get my head and an inspection mirror underneath and traced the leak to the Coolant temp sensor housing. Its actually coolant dripping out from between the seal and the side of the head (just below the tandem pump) which is why it looked like watered down oil as it was dripping down and dragging any crud and oil with it along the way!

 

Anyway, I have looked and only found posts about changing the temp sensor on the 1.4 petrol but not on the diesel VRS, and not even the Haynes manual has a section about removing the housing all together.

 

I spoke to TPS today who advised that they had a similar leak with a golf and the plastic housing had cracked as oposed to the seal giving up so I bought the housing as a full unit with the seal already in place as it was 5 quid more expensive for the full thing. However I now have to undo 3 coolant lines and a coolant temp sensor.

 

Could anyone instruct tell me if they have removed the whole housing before, and is it absolutely necessary to drain the whole system. If I dont drain it, and put up with coolant going everywhere and topping up later will this cause any air locks in the system. 

 

Any help is much appreciated, and I have attatched a pic of the offending part, held on by 2x10mm bolts which attach it onto the side of the head just under where the tandem pump is.

 

Cheers all....

 

Edited 5 January, 20179 yr by floydboy1

Drain the coolant from the tap on the bottom hose into a container, do the work, then just pour it back in again.

 

You're making it sound way harder than it really is. Airlocks are mostly mythology unless you have a French car, I've had brutal airlocks on Peugeot and Citroen engines which often require cunning techniques to bleed effectively but never really on VAG engines.

Drain the coolant from the tap on the bottom hose into a container, do the work, then just pour it back in again.

 

You're making it sound way harder than it really is. Airlocks are mostly mythology unless you have a French car, I've had brutal airlocks on Peugeot and Citroen engines which often require cunning techniques to bleed effectively but never really on VAG engines.

 

Drain the whole system or can i just get a few pints out to lower it half way on the radiator seeing as it wont be as high as the housing then which should allow me to change it with no leak?

 

Cheers for reply

When was the coolant last changed?

If you don't know I would empty the system and replace it.

The hardest part of the job you've got to do will probably be removing the pipes from the housing without damaging them as if they haven't been removed before they get a corrosion on them which acts like an adhesive.

Also the stupid standard VAG Spring hose clamps can be very awkward to remove and refit if you haven't got the special tool :)

When was the coolant last changed?

If you don't know I would empty the system and replace it.

The hardest part of the job you've got to do will probably be removing the pipes from the housing without damaging them as if they haven't been removed before they get a corrosion on them which acts like an adhesive.

Also the stupid standard VAG Spring hose clamps can be very awkward to remove and refit if you haven't got the special tool :)

 

 

The coolant was replaced just before buying the car around 4 months ago. They replaced it due to replacing the coolant reservoir as it was split and black.

In regards to the pipes, i bet they have never been replaced, although the housing does look very clean and new and you can still make out the writing on the side of the housing, so for a 160k car perhaps they have been changed as i wouldnt have thought it would look that clean if they hadnt from new! lol

 

Any idea where I can buy the tool and how much roughly as I did have trouble removing those spring clips on the fuel lines going into the tandem pump.

 

Cheers for response :)

 ive always used pliers on the clips for the fuel lines.

I too use pliers on fuel ones as they are small enough.

The coolant ones are more of a hassle,I use plumbers pliers on them,but it is a struggle tbh .

Search eBay for the proper spring clip pliers,loads on there.

It's a bit concerning to read the header tank was changed as it was black,as usually a black header tank on a derv means the head gasket is leaking and the tank goes black due to the combustion gasses escaping into the coolant system :(

And also the header tank cracking is another sign of possible head gasket failure,as the system gets highly pressurised with a leaking gasket and the tank can crack.