Hi, need a little help here from someone with a brain, I've disqualified myself.

Me old '79 244 with the Stromberg won't run with the crankcase ventilation hoses in place, just seems to have too much gas coming from the engine.

I've checked the compression, 90-92 and even across all four. I've also done a 'tune-up' and oil change(s). One of the side effects of this is that the oil goes black real quick after a change. Tried the old 'squirt the oil and recheck the compression', same results.

Oh, car is real low mileage, about 130k kilometers or 80k miles, had a cam belt at 70k miles.

Anyone run into this before?

Thanks heaps.

Compression is low. Should be around 150 psi +/-20. The book lists the minimum as 128 psi.

Probably should have a leak-down test performed. May need a valve job.

Check and see you have a working air filter element? Check ALL inlet hoses by removal and examination for wear & cracks-replace all old hard lines. Your symptoms indicate serious piston(?)/ head seal /valve gear failure. The fact that all 4 are equally bad indicates ring failure-perhaps caused by foreign paticles-hence above check, as valve gear isn't usually on all 4, neither is head seal failure. Check valve clearances-if all cylinders have one much too tight, then that's probably it, but it doesn't explain the blowby. Low mileage-perhaps it's been stored (salt air?) and corroded the bores? Or lots of very short runs-that'll do it too. If short runs-expect statrter motor wear to be considerable-check it. Is your cooling system ok, any obvious new parts there? Might indicate a cooked motor - cheaply patched and sold off as too hard/expensive to fix. There should be wet oil residue in the exhaust tailpipe, check sump oil for water contamination-milky, radiator for oil contamination-slick/scummy. Post again pls.

Q.
Compression check is done with warm motor and FULL throttle!!! Did you do this?

Thanks heaps for your replies guys. If the compression is really supposed to be that high then I think you've hit the nail. I ran the check warm but maybe not fully(?). And I've never heard that about keeping the throttle flap open but I suppose it makes sense. Gives the max air in to 'be' compressed.

Doesn't really act like a blown gasket, no water contamination and doesn't make that 'farting' sound. But if it was a cylinder to oil passage breach, and wasn't getting worse, then might not be obvious. Should still show as different compression on that cylinder though. Sounds like rings, but on a Volvo with that low Ks? I'm surprised. Exhaust is a clean as can be, that's one of the things that's throwing me. Would expect visible smoke if it was rings. Did I mention the Stromberg? I also can't get that set up. It either won't run (too lean) or semi-floods at idle until warm. I've been treating that as a symptom.

I expect you're right about the 'short runs', it was a granny car before we got it. Though I hate to even admit in this auspicious forum that I'm considering it, I wonder what would happen if I threw in a set of standard rings and took my chances? The car's a daily runner so taking it off the road for any length of time is going to be interesting, that and parts are getting hard to come by down here (Auckland, NZ).

I suppose for sanity’s sake I'll run the compression check again.

Doh! After writing all that, I realised I didn't really know what a leak-down test was. Sorry! I just sort of skipped over that. Now that I know what one is, I expect I'll have to get me one. Will post results.

Big thanks again for your consideration!

I doubt if it's rings. But I guess it's possible. Normally when you squirt oil in the cylinders, re-check the compression, and the compression doesn't change, that means either valves or head gasket. With bad rings the reading will normally come up.

A leak-down test should help narrow it down. If the shop doesn't know what a leak-down test is, or if they don't have the equipment for it, find another shop. It's not a DIY job unless you have air and gauges.

One thing for sure: less than about 130 psi compression and it's running very inefficiently.

Post back.

my concern is that it's all 4 cylinders together and even. It's hard to imagine a 4 cylinder head or valve problem that will do that-unless it's loose!!!!!!!!! It's why I thought 'rings'. A cheap re-ring is not going to earn my contempt, rather my pity that you haven't any alternative to do a 'proper' job. I fear you'll have to bore it tho' if it's as bad as I think it is. I hear NZ parts etc are worse than here in Oz. The strombergs won't let you get full air on crankover if they're like a Solex (CV/vacuum carb).-but the reading you get will just have to do. It would be lower than for EFI tho'. Grannies destroy cars, I've observed-they drive them to death without maintenance. Not a recommendation for anything.

BTW 90-92 WHAT? elephants per tonne?? what are the units-atmospheres/10 is abt right!!!

this is NZ so sheep/gumboot

seriuosly, check the diaphrams in Strombergs as that perish and have big holes in them and car she no go