Radiator Caps

[Chlorate]

Whilst I was mucking around with the alternator today I noticed that the expansion bottle cap on my Xant HDi wasn't sealing anymore (the rubber gasket in the cap has gone funny). Conveniently I had a spare cap in my toolbox - a leftover cap from my ZX TD. It's a bit old but it seals.

The springs feel about the same but I haven't had my thumbs calibrated recently

Anyone know if the coolant system pressure is similar between the 1.9TD and 110HDi engines?

Alex

[CitroJim]

Same as makes no odds as far as I know Alex..

[Chlorate]

I suspected so, thanks Jim. Always worth checking.

[Old-Guy]

For the last 3 or 4 years, since the heater matrix started weeping, our Xantia 1.9TD has been running around with the radiator cap not tightened down properly so that the cooling system isn't pressurised. No problems even on long and (more or less legally) fast journeys.

[Chlorate]

That makes sense.
I guess you could say is that the rad cap blow off valve is only really necessary if the coolant is overpressurising. As far as I can tell the head gasket in my car is healthy, so no worries needed then.