Water Leak

[dave1981]

My mrs has mk2 51 plate galaxy 1.9tdi ghia manual. It loses water when running but no signs of head gasket going and can't find any leaks. I was told today that a retorque of the head bolts cured exactly the same problem on others so does anyone know the torque settings for the head bolts or have any other suggestions as to where its losing water from? Thanks

[chrispb123456]

Hi Dave

Further to what I said yesterday about pressure, on any vehicle with no problems as the engine heats up to normal operating temperature the pressure rises steadily but stays below the maximum pressure cap setting this is due to expansion, as the engine cools down and after standing overnight when you remove the cap there would be no pressure, this is normal..

 

In your case you said there was pressure there when cold, this is not expansion pressure that's still present but combustion pressure that's been forced into the water jacket.

The commonest cause of this is head gasket failure and if left to long like this will require the head to be refaced.

Now it's possible there may be a couple of things that haven't helped the situation.

The early PD engines suffered with the water pump impeller breaking up and for low speed driving around town you wouldn't even notice anything is wrong, the problem usually shows itself when you take it out on a motorway and drive it hard then the temperature can suddenly shot up with a loss of coolant through the cap.

 

The other possibility is the auxiliary coolant pump (run on pump) has packed up, this should run all the time engines running and carry on for 3 minutes after switch off, it's to stop hot spots building up in cylinder head and provide circulation through the rear heater and the diesel fired booster heater under the car.

 

You can also suffer with heater blowing cold when it should be hot, fluctuating temperature gauge and erratic coolant levels

 

Re torquing of the head bolts is something we used to do years ago on cast iron cylinder heads with high tensile bolt or studs with nuts and washers.

These days they use aluminium heads and stretch bolts which you are advised not to re use, you also tighten in four or five stages, first two stages are usually using a torque wrench in the normal manner but the last two or three stages are by angle tightening and that's it no further tightening..

 

By further tightening you run the risk of distortion, or worse snapping a bolt off in the block 

[dave1981]

Oh no!!!! Was dreading it being the head gasket. Dont suppose id get much change out of

[insanitybeard]

Another thing to bear in mind- I'm not sure if the unit injectors may have to be removed in order to skim the head, if they do, care will be required to set them back up correctly a) so that they seal properly, especially with all of the o-rings fitted to them for low pressure fuel supply, and 2) so that they are orientated correctly- though I'm not quite sure how you are supposed to be able to set them in position with accuracy to tenths of a millimetre as per the procedure in Ford's technical data! 

 

To be honest, I'd be impressed if you could get all that work done by somebody else including parts for

Edited March 26, 2014 by insanitybeard

[xavier]

Check the rad fine is working. Mine overheated today when towing a caravan, when I checked under the bonnet no fan running. Wouldn't have noticed under normal driving I think, just happened after barrelling up an incline on the m-way with the van on the back.

[xavier]

That should be fan, not fine!

[xavier]

Update on this, have replaced the sensor but no joy. Plus point is I've discovered the hose from the thermostat to rad isn't the one I thought it was and remains cold once engine is to temperature. Looking over the history of the car I believe the thermostat has never been replaced so I figured I'd try that this evening. But how are you meant to get the bolts off?! Firstly, can anyone confirm if they're a 10mm outer, or hex (or torx) inner as I can't get anything to fit as solidly as I'd like. And how are you meant to get them off (and back in again!) once you get said socket on the things? I'm thinking remove the alternator but looking at it the aircon pump might need to move too.