Low compression all four cylinders

E

Eldin

Greenie N00B Member
Really wierd one here.

Long story short, put a cx7 engine into a blown ms3.

Pulling the valve cover found after install that the oil is a bit milky. All four cylinders show about 30psi cold for compression. For reference, my ms6 cold shows about 150.

Any idea what the FUCK is going on Figure it's a head gasket, but I thought that was typically limited to one or two cylinders?
 
It's possible your timing chain is stretched or VVT is sticky and your valves are slightly open. Also, throttle has to blocked wide open or it cant get proper air. Might have to do a leakdown test to know for sure.
 
Sounds like you got a dud and need a refund. Leak down test + teardown will yell you what's going on sure could be a failed head gaskets but only one way to know
 
Every time a CX-7 valve cover has been removed that I have seen, it is sludged up to Hell because the owner was a no-maintenance type of person. It's like getting a "JDM" engine that 99% are completely shot.
 
Raider said:
Every time a CX-7 valve cover has been removed that I have seen, it is sludged up to Hell because the owner was a no-maintenance type of person. It's like getting a "JDM" engine that 99% are completely shot.
Click to expand...
Definitely keeping this in mind going forward, might buy a scope and just check the engines more before purchase

Leakdown was bad across the board, compression was also poor. At this point I was planning on pulling the timing and then checking compression. If that's fine I'll just do a vvt job, otherwise I'll rebuild the original engine as it just had a bad rod bearing.
 
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