I had a compression test done on my 2000 S40 (115,000 miles) and it cameup with low compression on only one cylinder (cylinder 1); 70 PSI. My mechanic (Volvo shop, non-dealer) said it was a "burnt"exhaust valve and gave me a quote of $1,600 to fix. I've also noticed that I've been burning oilrecently and I keepgettinga #P0014check engine code, which I understand can also be related to low compression with cylinder 1. I also recently had to replace the spark plug for cylinder 1 after themisfire code (#P0301) was tripped.

So my question: Based on what I've described, does it sound like a bad exhaust valve? In reviewing the posts, I couldn't find a lot of issues with valves in the S40, so I thought I'd see if anyone had a similar repair or has other ideas as to the cause.

Thank you!

 

One way to tell if it's a valve or rings is to put air pressure into the spark plug hole with the engine at TDC for the cylinder in question. Then listen for where the air is escaping. Is it coming out of the oil fill hole? Then rings. Is it coming out of the throttle body? Then intake valve. Out the exhaust port? Then the exhaust valve.

$1600 is quite expensive. You could get a whole engine for that amount. You could save a bunch of money removing the head yourself and taking it to a machine shop for the valve work.

 

Usually a burn't Valve will be 0 compression. But it might only be slightly burn't.
$1600.00 is about the going rate. The Valves them selves are like $50.00 or more each.