97 Avensis Air Con And Temperature Guage Problem

[clairesimpson]

Hello

I wondering if anyone can help me with this one.... Recemtly my air con and temperature guage has gone a bit wacky. I'm fairly sure that before when I turned on the air con to warm it warmed up fairly instantaneously, however, recently its taking up to 10 mins+ to get warm. When it does get there it then is intermittent and goes cold again very quickly. I have noticed that this happens mainly when I'm stuck in slow moving traffic and is very worryingly accompanied by the needle on my temperature guage shooting up from mid guage to the red area in a second or two, then the needle drops down when I move just as quickly and the air con gets warmer.

I've taken it to the garage once and they couldn't find anything wrong.

Has anyone got any ideas?

[Penfold]

Sounds like it might be an air lock in the cooling circuit. It goes away when the engine is revving higher under load and hence the water pump is circulating the restricted flow with more pressure.

Questions for you. If sitting in traffic with the needle in the red;

1. Does the cooling fan kick in

2. If you bring the engine revs up for a while does the problem go away (ok so you're gonna **** off the people around you but it has to be tested)

Assuming of course that the coolant levels are OK, pipes aren't leaking and screw cap seals are not perished.

The cure for an air lock is to drain/refill the system and re-test. Good Luck.

If this doesn't fix it then take it to another garage for a second opinion as running it in the red for too long will ruin the head gasket and subsequently the engine.

[clairesimpson]

Thank you very much.

I'll give your advice a shot

Much appreciated!!

:)