2001 Astra 1.7 Dti coolant level drop - billy the fish
After changing the engine oil I performed the usual checks and noticed that the coolant level had dropped by 1.5 inches below the COLD level on the coolant reservoir. I topped it up to the correct level and two days later it has fallen again by about 1 inch.
Please, has anyone got any ideas as to why this might happened?

Many thanks



2001 Astra 1.7 Dti coolant level drop - Ralph Bayley
I assume you've checked for leaks if this is the case you may have a head gasket problem or posibly a cracked cylinder head.
2001 Astra 1.7 Dti coolant level drop - billy the fish
Thanks for your reply Ralph.

The hoses that attach to the reservoir itself are sound. Where else should I check? The radiator and ...?
My Dad suggested a similar cause to you.
He also suggested holding my hand 2-3 inches from the exhaust when the engine is warmed up to see if there is any water vapour in the emissions. I did this when I got to work this morning after an 11 mile run ? nothing, bone dry.
So what is the next test after checking for obvious leaks? Pressure testing the coolant system at a garage?

If it is a head gasket problem or a cracked cylinder head, does this mean the engine is knackered?

Billy
2001 Astra 1.7 Dti coolant level drop - John S
You won't pick up any vapour in the exhaust unless the water leakage rate is really high, much higher than your car - and anyway it's all confused by the fact that one of the products of combustion of petrol is water vapour, so you'd always expect some visible water vapour on a cold start.

Certainly a pressure test should show internal gasket defects, but it could be a hose or hose joint leak. Carefuly check all around looking for antifreeze stains on the hose joints and on the radiator. Not easy, though in a packed engine bay.

The other thing worth trying is to look at the spark plugs. If a substantial amount of water is going onto one cylinder it tends to clean the plug up and it'll look different to the others.

JS
2001 Astra 1.7 Dti coolant level drop - John S
Must read the post! It's a diesel isn't it?

Shambles off, muttering.........

JS

2001 Astra 1.7 Dti coolant level drop - billy the fish
No worries John.

I'll check the hoses etc after my run home tonight.

Thanks for your reply.

Billy
2001 Astra 1.7 Dti coolant level drop - mountainkat
another good possibility is Core plugs leaking - had the very same thing on my Ford Puma last year, unfortunately I'm not familiar with the Astra engine so can't tell you where to look, core plugs are pretty obvious though.
2001 Astra 1.7 Dti coolant level drop - Ralph Bayley
My astra 1.7 dti was loosing coolant and I couldn't see where it was going.In 3 days and less than 150 miles I had to top it up with 7 Litres and I still could not find a leak.

The car went back to the garage where eventually they discovered that the head had a tiny crack in it. The head was replaced and all is now well (appart from Kangaroo Juice! [see my thread])

Is your engine an Isuzu 16 valve or a vauxhall engine (the isuzu engine has the code Y17DT) as I believe the Isuzu is more prone to this failing and yes mine is an Isuzu engined version! As for cost I'm sorry I can't say as the repair to my engine was carried out under warranty but I have a feeling a recon head is about £400 (expensive because of the 16 Valves so I'm told)