Poor compression in 3 cylinders.

[avant-garde]

Hi, I need some good advice on what I should do about my 1970cc Aircooled engine. I've read the post regarding poor compression, but I still need help.

I took my '82 T25 to be tuned-up the other day and when I picked it up (after hitting one of the customers cars there prior to the tune-up), the mechanic told me that there was poor compression in 3 of the cylinders. He mentioned that 3 of the cylinders had around 80psi and the other had 150psi. It cost me £135 for him to tell me that!
£85 +VAT for the Rover tail-light and £35 for the non existent tune-up -

Thinking out loud...and typing it down now...

What I need to get my head around is can I repair the engine or do I need to replace it ? I would rather replace the parts that need replacing as opposed to buying a recon engine - advice needed please.

elitevw up in Essex do a recon engine for around £950...

Could I replace the parts that cause bad compression for less than that ?

...and because I know next to nothing about engines what parts normally cause poor compression ?

I thank you in advance.
Kevin.

[ghost123uk]

£135 for a quick compression test !!!!

The first thing you need is a friendly local VW Aircooled experienced mechanic

I bet someone will be along soon to recommend one in your area - or you could have a look in our "wiki" up there ^^^ under the "Garages" section to see if a decent mechanic is listed near to you.

It might just need the tappets doing (or it might be a cracked head(s) = less good )

elitevw up in Essex do a recon engine for around £950... Could I replace the parts that cause bad compression for less than that ?

Almost certainly

...and because I know next to nothing about engines what parts normally cause poor compression ?

Worn piston rings (and possibly pistons and liners as well) - any of which should make it use oil and make blue smoke when accelerating.

Tappets set too tight - easy fix (but bad for your engine if run like that for long).

Head to liner joint leaking (often due to head bolts being wrongly tightened)

Cracked heads - worst case really as they are easy to fit but quite expensive.

If it runs OK doesn't make nasty knocking noises (other than perhaps tappets "tapping") and doesn't use oil or blow blue smoke, then a re-con engine is most likely NOT needed !

Keep in touch re this

OH and Hi by the way

[avant-garde]

Many thanks ghost123uk for that info and advice

I will go down to my local garage - (not the one that charged me £135 for one hrs work) with this info and see what they say.

I'll let you know what happens when I know.

Thanks again,
Kevin.

[ghost123uk]

Many thanks ghost123uk for that info and advice

I will go down to my local garage - (not the one that charged me £135 for one hrs work) with this info and see what they say.

I'll let you know what happens when I know.

Thanks again,
Kevin.

If you can hang, on I bet someone near you that is on here will offer to help either directly or by advising a known good VW place. (it is one of the many things this forum is good at - wait until they all get home from work, eat there dinner and then log on )

[jason k]

as lomg as the rest is ok , whack a set of pistons and barrels on it.

hell even a 2.1 kit is cheap enough!

[toomanytoys]

How does it drive? does it get along alright (no they are not fast) does it smoke?

compression test is often a red hearring as the hydraulic lifters are not being "pounded" hard enough.. the only way to do a propper compression test is to winf the tappets out so they are either just touching or a tiny amount of clearance at each cyls TDC, then perform the test..

Oh.. have you got a haynes manual for it? if not get one.. at least then you can give the correct info to whoever will be "tuning it up"

[Wolfsburg Willy]

Hi Avant-garde and welcome. This whole thing smells a bit fishy to me. Usually, the results of a compression test will show one cylinder down, it's quite unusual to have three down and no noticeable loss in power. As suggested, find yourself a good mechanic who knows his air-cooled 'dubs and have the test repeated. The test itself can be done either the 'traditional' way using a hand-held compression tester or by using an expensive gizmo that uses other engine parameters to arrive at compression figures. I have in the past found that figures from the gizmo were way out (worse) when compared with the hand-held tester. So a second, basic, test might show things in a better light. If all else fails, do as Ghost says and get new barrels and pistons.

[avant-garde]

Thanks for that. I think 'not fast' is an understatement of the year - 10mph to 15mph up any type of incline and 40mph with the wind behind me on the flat. That's the reason why I took it into the garage for a tune up in the first place.

I can't see any smoke...but the thing that worries me is the over excessive distance cars leave behind me. I'm not that bad a driver !!!

I've contacted a VW specialist at http://50-67.com/index.php" onclick="window.open(this.href);return false;
so fingers crossed they will know exactly what to do - worse case scenario etc.

I'll let you know how I get on.

Many thanks to you all for the advice.

Kevin.

[orangebooboobearcrew]

Where can you get a 2.1 set of barrels and pistons from as mentioned by jason k above?

Got our 2.0l Aircooled out and stripped at the moment and looking at doing a top end rebuild...

[avant-garde]

Okay...took my bus to the VW specialists over in Chacewater and the results of the compression test are: No 1-85, No 4-80, N0 3-55 and No 2-75.
No 3 plug found to be oiled up and No 3 cylinder not firing. Engine has bottom end rattle. Would recommend engine is replaced.

So there we have it. I am now looking for a 2nd hand 2ltr Aircooled engine for a 1982 Type 25. I don't really want to spend anymore than say £500 on a good 2nd hand engine. If anyone knows of anyone selling one please let me know. Thanks.

To make it even worse the VW people said that they had a 2ltr Aircooled engine 4 weeks ago which was in perfect working order - they sold it for £150.

[ghost123uk]

the VW people said that they had a 2ltr Aircooled engine 4 weeks ago which was in perfect working order - they sold it for £150.

The first thing that occurred to me on reading that is they are either fools, or are lying about it !! - therefore beware of them !

.

[jason k]

Where can you get a 2.1 set of barrels and pistons from as mentioned by jason k above?

Got our 2.0l Aircooled out and stripped at the moment and looking at doing a top end rebuild...

speak to jh engines and iirc cool air sell em too

[avant-garde]

I also wondered why the guy would say that about the engine after it had been sold - what was the point in doing that other than to pis*s me off (on my birthday of all days).

After extensive research and phone calls etc, looking for a 2ltr Type 4 engine to put into my Type 25 camper...bottom line is that unless I spend £1k upwards I'm not going to be able to get one. One VW company told me that I could use a Type2 2litre with some modifications. Any views on that would be welcome.

Some VW specialists say no point reconditioning your knackered Type 4 engine while some say that it would be easier and cheaper to do so. I think I have contacted too many people and it's the case of too much information - my head is going to explode

While I'm here, can anyone tell me if the elitevw.com recon engines are any good - does anyone know what they do to them before they sell them on and are ancillaries included ?

For example Vege and TES; crack tested crankcase, reground crankshaft, new main bearings, new big end bearings, new camshaft bearings, new camshaft, new cam followers, new barrels, new piston with rings, new gudgeon pins, new flywheel oil seal, refaced flywheel, new cylinder heads, new valves, new spark plugs, fitting gaskets, built to run on unleaded fuel etc

Cheers,
Kevin.