C5 2.2HDi Facelift Head Gaskets & Coolant Bleeding

[skycat61]

Oh, woe is me!

When I started the car this morning from cold I got huge clouds of white smoke and the car missed a bit. I got out and checked and smoke did not smell of oil. I drove it for a mile and the smoke went but after 10 miles it overheated as I got to work. I let it cool down then topped up the water (perhaps 1 litre). It drove back home fine and I picked up some Steel Seal head gasket sealant.

I got home drained some of the coolant and put in SS, topped up with anti freeze, and ran the thing on tickover as per the instructions and then went for a drive where it overheated almost immediately. Topped up with a further two litres ow water but its still overheating.

I think I've got air trapped in the system because the heater won't warm up.

Does anybody know where the bleed valves are on this car?

[white exec]

If the clouds of white smoke (more when accelerating) smell faintly "sweet", then it's likely to be ethylene glycol (coolant) getting into a combustion chamber and burning, along with the fuel. Points to head gasket gone, which might also explain the overheating (hot combustion gases getting into the coolant, again via HG leak). If the latter, the coolant will start to small of exhaust; insert nose into expansion tank filler.

Ethylene glycol burning was a basis for Stage Smoke. Dramatic stuff.

Good idea to check everything is bled properly. If you get rid of the 'air', and the HG's gone, you can expect it to return - hot exhaust gases.

[Stickyfinger]

Errr.....fix the leak ?......................sealants are rubbish, damage or block the heater matrix and oil coolers.

[Peter.N.]

Strangely enough the same thing happened to me with my 2.0. Hdi C5, a few days before we were supposed to be going on holiday. I got a few miles along the lanes and was suddenly surrounded by what looked like a 1950s smog, I stopped the car but couldn't even see to turn round until it had cleared, as it was accompanied by a bit of diesel knock I suspected an injector and what was coming out of the exhaust was unburnt fuel - not so, got home, no water. The car is now sitting with a row of XMs at the top of our field.

The only thing I did find was that it stopped doing it if you left the filler cap undone.

Peter

[white exec]

The only thing I did find was that it stopped doing it if you left the filler cap undone.

Definitely HG, and a leak between a waterway and a combustion chamber. Removing the pressure from the cooling system (cap off) reduces the amount of coolant that gets injected into the bore, and lets injected exhaust gases escape from the coolant.

Our BX did all this big-time. It could create clouds big enough to white-out an entire street!

[Peter.N.]

Yes, it was only when the water got hot and the pressure rose it got forced past the gasket. I had a 2.1 XM estate with a leaky gasket which I ran for years with the cap loose, it eventually succumbed to rust, but of course it depends how bad the leak is, and remember it lowers the boiling point of the water.

Peter

[skycat61]

I managed to find the engine bleed cap and vented the air. No over heat now but still runs a bit warm. Vented some more air when got home this evening. I still can't find the bleed for the heater matrix - does anybody know where this is?