Low Compression 2nd Cylinder - Serious?

[bertnuggit]

My camper has compression of 80 in the 2nd Cylinder, others are around 130 ... according to mechanic ....

Internet mentions problem could be a bad exhaust valve?
There's nothing much about exhaust valves in my Haynes, big job to check out???

Just wondering if 80 is very low, bad enough to worry about?

[Aidan]

you need to check the valve clearances first in case you have a lifter too far open first, that's in the haynes; if that's ok then normal check is oil in compression test to check the rings but if flat4 this doesn't work well
valve lapping is a head off job,
my lowest cyl is 7 bar which is just under 100 the rest 125+, number 1 is normally lowest on wbx, runs ok so it's staying in

[bertnuggit]

Thanks Aiden,

I'll check Haynes & see if it's something I can attempt (I'm a learner...).

Otherwise, I'll drive it for a while (recently bought it) before getting anything major done.