2003 V70 low compression

[SuperHerman]

I noticed your engine is an LPG conversion. LPG conversions are known to burn valves and/or ruin valve seats. This could be the cause of your compression issues. Although you have the BRC Valve Saver a valve and/or valve seat issue is probable and one of the first things to look into.

With a camera scope you can eliminate this problem by taking out the spark plugs and putting the camera into the spark plug holes. USB cameras that connect to a laptop can be found for $10 or so on eBay.

Here is a video of a tech using a camera to inspect valves with the head in the car.


If a bad valve and/or valve seat is confirmed repair requires pulling the head and fixing the issues. Other than removing the LPG system, there is a huge number of posts on this forum on the actual repair. All of the Volvo 5 cylinder engines are pretty much the same. A few things change, but the procedure is not too different.

Here is a write up on changing a head gasket on a Volvo 850. How to replace the head gasket on a volvo 850

Another write up is here: viewtopic.php?f=1&t=26864

Do some more looking on the site, but basically, like all cylinder head removals, you have to pull the intake and exhaust manifolds and then remove the head. Volvos differ from some cars as the top cover is also part of the head - so pay attention to removal or you may damage the cams or top valve cover. In addition the VVT set up for timing can be a bit tricky. Marking and proper tools is a must.