I got a misfire in cylinder one and two. I took it to get a compression test and they told me it had low compression in cylinder one. I don't believe he tested the other cylinders. What could be the causes of low compression? Ive read it could be piston rings damage to cylinder wall crack to a head gasket. Any one to determine what it could be without removing the head? I've never removed a DOHC engine and I hate to start taking it apart and it be an engine block problem.

u can borescope it, if u have one, altho that may or maynot help u find the issue

depending on what kinda car it is and the over all condition, most likely not worth fucking with

it's a 15' range rover evoque with the 2.0. I was going to check auto zone to see if they have one to rent.

yeah in that case it would be good to check. if its not milking the oil or burning/using water id have a hard time thinking it was a gasket/crack in the block

Pretty sure its a ford engine, so start by doing a decarbon

carbon build up very common issue on those gdi engine which cause misfire, low compression, valve bending and a bunch of fun problem

This post was edited by Subban3gr0 on Aug 19 2019 02:43pm

That's what I was thinking. It's not burning oil or milky or anything.



I actually used the crc gdi carbon cleaner last night. It did seem to smooth out the idle a bit but it is still rough. Would it hurt to maybe run another one?

If you really want to decarbon you should pull off the intake. A good soak overnight does wonders.

How many miles do you have?

74k

Well you might need more than a cleaner then
Anyways 99% of those low compression/ idle complain ive been through have been fixed with carbon removal manually or with stuff like you used
For my part i use wynns decarbon on my client cars, it the best one ive found so far
You have to use it right tho