Vauxhall Astra G Petrol 1.6 - 'Using' coolant... normal?

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Sat 29 Jan 2011 00:04
Vauxhall Astra G Petrol 1.6 - 'Using' coolant... normal? - cosmicjazzer

I've been looking to purchase a reasonable estate car for under £1,000 and today viewed a very nice Astra 1.6. (16 valve ecotec engine). It seemed to tick all the right boxes: FSH including cambelt, good body, 120k, newish brakes and tyres, drives and sounds just like new, £900. So far so good. But the very decent seeming seller volunteered that the car 'uses' a little coolant (but with no sign of any leak) but that his mechanic had told him this was normal for an Astra.

I'm just slightly worried about this water 'use'. Perhaps I'm barking entirely up the wrong tree here (I really know very little about cars...) but I'm wondering if the head gasket could be just starting to fail? Is there any way that I (or someone more in the know) could properly check this?

Difficult to say but I thought the exhaust perhaps looked a little on the 'steamy' side... but it must be said I'm not really sure what i should be looking for here... Oil on dipstick and around filler cap was nice brown colour, no mayo, and engine was very nippy and purred like new.

Thoughts anyone?! Am I worrying unduly?

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Sat 29 Jan 2011 01:00
Vauxhall Astra G Petrol 1.6 - 'Using' coolant... normal? - unthrottled
It's honest of the seller, but I'd walk away-there are lots of 1.6 Astras around. For a £1000 you can't expect, nearly new condition, but I'd stay clear of known unknown problems (if that makes sense!)

A head gasket is a cheap fix for a competent DIY enthusiast but, it's a big step up from changing oil and plugs. Now, most cars will have a 'steamy' exhaust when idling in cold weather and differentiating between normal exhaust condensation and escaped coolant isn't easy. In general, normal exhaust vapour should be 'light' and 'fluffy', and have a tendency to rise upwards from the exhaust. A blown gasket tends to produce 'heavier' steam which has a tendency to hug the ground like fog. If there is sufficient antifreeze (a big IF!) then the exhaust might smell sweet. Sometimes a failed head gasket manifests itself as oil in the coolant. A bit of scum in the header tank is normal, but an oily sheen is not. Alternatively, there may be coolant in the oil. Looking for mayonaise on the oil filler cap is a good start. but it only really works if the engine is cool. It can also be a false positive-Ive got a bit of emulsion on the filler cap but I'm confident that the h/g is fine. Take the dipstick out, and press the oily part against the HOT exhaust manifold (not the heat shield). It should burn with an acrid smell. If it snaps, crackles and pops, there's water in the oil! Other signs? Having left the engine to stand overnight, remove the spark plugs, then crank the engine. It's common for water to slowly seep into the cylinder where the breach is. Upon cranking, it'll be ejected from the spark plug hole. Head gasket failure doesn't always involve coolant and smoke. If the h/g is breached between cylinders, there are no symptoms until the combustion gases from one cylinder cross over into an adjacent one and ignite it prematurely, creating an unmistakable knocking sound . Compression testing will reveal two adjacent cylinders to have low compression.

Finally, head gaskets seldom fail without an underlying reason. The most common one is overheating which causes the cylinder head to expand, crushing the head gasket. Overheating can warp or even crack heads. That's probably more than you wanted to know about h/g!

Edited by unthrottled on 29/01/2011 at 01:03

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Sat 29 Jan 2011 11:23
Vauxhall Astra G Petrol 1.6 - 'Using' coolant... normal? - cosmicjazzer
unthrottled: Thanks for your very helpful reply. All very interesting!

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Sun 30 Jan 2011 15:39
Vauxhall Astra G Petrol 1.6 - 'Using' coolant... normal? - cosmicjazzer
Must say I remain a bit tempted by this car... Seemed, overall, much better than others I've seen at the price... Just thinking about worse case scenario and wondering what the going rate is for a garage to change head gasket... Guess I'd best ring a couple of garages but any ballpark figures would be of interest!
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Sun 30 Jan 2011 18:09
Vauxhall Astra G Petrol 1.6 - 'Using' coolant... normal? - unthrottled
Ooh-£300 ish from an indie. The scrappage scheme pulled a lot of perfectly good older cars off the road-which provided independant garages with a lot of their business, so you should get a good price. Since the head has to come off, it's as well to bite the bullet and get them to throw on a new timing belt and water pump while they're at it. (hopefully) you should get a lot more miles from it. I have a soft spot for those astras, generally reliable, great cruisers, cheap parts, and decent to drive-if you get a good one, the actual cost per mile will make a lot of TD drivers weep ;)
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Sun 30 Jan 2011 23:01
Vauxhall Astra G Petrol 1.6 - 'Using' coolant... normal? - clewsy01

These are generally sound cars when looked after, I would be tempted if your still interested to go back and have another good luck, see if the coolant level has gone down since you last looked and then if you wanted make him an a fair offer, one that would compensate paritly for some work to be done,

If you make a crazy low offer and he accepts, maybe just maybe he knows more about the car than letting on and something is wrong and he want shot ASAP.

£300 seems a nice fair HG change to me, not too hard a job in all honesty, and pretty much straight forward to do for a garage, but defo get a new belt and pump on. With all that done the engine should be sound untill 160k when a new timing belt would be due. (40k intervals)

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