Headgasket Gone?

[Guest stevesxantia]

HI and this is my first topic.

 

I hoped that my topic was less critical as I fear my car has an expensive bill looming.

 

My 1.9 td Xantia had been losing about a kettle of water a week ( 700 miles average) and I kept topping up half suspecting what was happening.

 

Now the car is very hard to start first thing and when I try to 'pinch ' the top rubber coolant hose it is hard as rock. ( in fact when I took the filler cap off it flew 5 feet into the air!)

 

Is this the dreaded head gasket gone?

[Guest Xantia Pilot]

It does indeed sound like the head gasket. But what was once true of headgaskets is no longer to be taken on trust. The petrol-engined Xantias have a "plastic" composite head gasket, which is susceptible to burning through.

Burning through is entirely different from when the headgasket develops a leak after the engine has been overheated. That leak is due to the head warping, caused by a metallurgical process call stress-relieving. If the head did get that hot, even briefly, then it is indeed an expensive repair.

However, If there has been no extreme temperature event, then there is a good chance that a new head gasket can be slid in to replace the cactus one. I have done this on my 1994 Xantia without fully removing the head - without even removing the exhaust manifold. I did fit new headbolts, because I had already re-torqued them several years earlier to silence an earlier gasket leak (the modern system takes the bolts int plastic deformation, of which they can accommodate only so much).

The main concern would be whether corrosion has dug a shallow channel along the path of the leak. There was none on my block or head when the engine was 13 years old, so I cleaned the surfaces, slid in a new gasket, and torqued to specification ... no further problem, despite the cynicism of some armchair experts.

[Guest fs2811]

Head gaskets on Xantia turbo diesels seem to fail earlier than on the non-turbo models. Some sealant can be added to the coolant in early days of water loss. When the head gasket is replaced, it is essential that the coolant is drained and the engine flushed, at least every two years; and the strongest solution of anti-corrosive antifreeze is added. Looking after your cooling system in this way will extend the life expectancy of the head gasket. Finally, remember to bleed the system of air pockets from both the engine and the radiator bleed valves.