Losing Compression

CrunchyAdams82 · Post by **CrunchyAdams82** » Wed Oct 02, 2013 7:04 am

Alright peeps,

I think I'm losing compression in my B20 engine.

Symptoms are;

- Feels laboured
- Has a bit of a stutter under throttle occasionally
- Idles rough
- Two of the spark plugs had oil around them

I'm changing the engine in my car to a 2.2 early next year, so don't want to spend any money on this one really. So my questions are;

1. If it is compression, how expensive is such a fix?
2. If I drive it carefully will it be ok, or is it likely to get progressively worse?
3. Could it just be the rocker cover gasket?

Any input would be appreciated.

Cheers, Andy

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Wed Oct 02, 2013 8:08 am

Laboured running, stuttering and rough idling could be caused by plug electrodes being contaminated by oil, but could also be caused by numerous other problems on the ignition/injection side.

Since you say you've already found the plugs to be oiled up once, best thing to do I suggest is take the plugs out and re-check them for contamination and while you're there, do a compression test. Compression testers don't cost much these days and the test is easy enough to do. That would confirm/put to bed that theory.

EDIT: if it is compression you'd be best off just bringing forward the h22 swap because it means taking your existing engine out or apart in situ anyway...

bristol_bb4 · Post by **bristol_bb4** » Wed Oct 02, 2013 8:14 am

Worth taking the valve cover off and checking the spark plug seals, had symptoms like this a while ago and ted found the cause when he went to change my plug wires for me

CrunchyAdams82 · Post by **CrunchyAdams82** » Wed Oct 02, 2013 9:39 am

Cheers guys. Changed the plugs & there was no difference at the time. But since then the problem has got slightly worse.

Haven't tried changing the leads though, but I doubt it's that. Must be related to the oil around the plugs me thinks.

I'll do a compression test & remove the rocker cover to inspect the gasket and spark plug seals to start with, then see where we are.

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Wed Oct 02, 2013 9:54 am

Did it get instantly worse when you changed the plugs?

CrunchyAdams82 · Post by **CrunchyAdams82** » Wed Oct 02, 2013 9:56 am

No. It's been about 2/3 weeks since I changed them.

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Wed Oct 02, 2013 9:57 am

Ok - not a problem with gapping of the plugs etc then.

bristol_bb4 · Post by **bristol_bb4** » Wed Oct 02, 2013 10:05 am

Haven't tried changing the leads though, but I doubt it's that. Must be related to the oil around the plugs me thinks.

Yeah what I'm sayin is, he took the leads out and they were caked in oil, changed the valve cover gasket and spark plug gaskets and problem fixed lol

CrunchyAdams82 · Post by **CrunchyAdams82** » Wed Oct 02, 2013 11:24 am

Nice one. Hopefully it's something that simple.

Lude Generation

Losing Compression

Losing Compression

Re: Losing Compression