Practically Classics Forum

Hi,
Managed to prise the Alpine out of the garage yesterday after a long lay up - after priming all started a treat. Blasted the cob-webs out a little - well at least as many as I could without an MOT (i.e. on the drive). However, I noticed that there was back pressure from the oil filler cap and potentially blow back, with some fumes? It was not there before lay-up.
I did a compression test and compressions were 12.1, 11.1, 12.1, 12.1 bar (if that was the units?). Nonetheless, within tolerance. Oil pressure was good. 50-75 psi, depending on revs. Its possible that it sounds a little "tappety", although again was good at lay-up. I am suspecting a sticking valve, but was wondering whether anyone else may have suggestions?
Cheers!
Andy

That's 175psi x 3 and 1 at 160psi so nothing too worrying there, though the 15psi difference between the low one and the others might be a sign of a slightly sticking valve or a tight clearance. ISTR that these engines tend to be heavy breathing things even at low mileage and when otherwise perfectly fit so unless it's filling the entire engine bay with oil mist and leaving huge clouds everywhere I'd try a good blast out first and see what that low figure looks like afterwards, though even it is within acceptable distance of the other three figures. Tell us what effect this has and report back please.

AlpineAndy wrote: after a long lay up

I think that's the telling phrase, get some miles on it before starting to panic.

harvey wrote:

AlpineAndy wrote: after a long lay up

I think that's the telling phrase, get some miles on it before starting to panic.

Sticky rings needing a bit of exercise and some oil flow around the engine to free them off?

Thanks for the suggestions - I will treat it to some Red X and give it a bit of a thrash and get the cobwebs blown away.

Cheers!

Andy

I believe that is called an "Italian tuneup". All cars need one every so often

TerryG wrote:I believe that is called an "Italian tuneup". All cars need one every so often

Also applies to Swedish cars - my Volvo V70 diesel failed MOT on emissions so the tester filled it full of something and took it for a blast down the A52 from Derby to M1 and back and then tested it again when it rather warm - result - a pass !!

You do not mention the system used when doing your compression test. The correct method, known as ' wet and dry' allows testing the rings and valves separately. Firstly, the dry run, which I suspect you did, tests the total cylinder compression. For the second, the wet, 2 or 3 squirts from an oil can is injected into a cylinder and the reading noted again. This has the effect of temporarily sealing the top compression ring, with any lowering of a cylinder's reading, compared to its dry one, indicating a leaking valve.

Pavel

Thanks Pavel - I had done the dry compression test. I will also go back and retest with the wet Method - funnily enough I was just thinking today I should try that; if nothing else just to gain some information on the general internal condition.

Cheers,
Andy

Has your Alpine got a hose from the rocker cover to the air cleaner? If it has check that it is not blocked. I had a Fiat 127 which had a similar problem and cured it by removing the spark arrester ( looked like a piece of bottle brush ) from the hose which was completely gummed up and replaced it with a piece of loosely rolled wire wool. I had replaced 2 rocker gaskets to try to cure oil leaks before finding the blockage, the reason for the leaks.