[TC.Barky]

Hey all,

As per title, got some oil on the spark plugs (1-3, 4 looks ok) and layering the intake and using oil with no leaks. No noteworthy smoke. Thinking PCV, just replace? Any suggested tests to prove? Anything else I should look for or be doing?

TIA

[Gwagensteve]

Think through this logically. If the PCV was the fault, all plugs would be fouled equally.

If it doesn't smoke on startup it's likely rings. If it smokes on startup, it's likely valve stem seals.

Disconnect the rocker cover breather with the car at temperature and you'll soon know - if it's pumping out air/vapour it's rings, and that oil vapour is what's being drawn into the intake. The residual vapour is what's on #4, 1-3 have ring/bore wear and thats what your seeing on them.

If there's not all that much blow-by, it could be valve stem seals, but you'll normally get smoke on startup and overrun.

[TC.Barky]

Yeah thanks I thought that may be the case given 4 looked different but was hopeful it could still be pcv. So I followed it in another car and although no visible smoke can definitely smell it. Not super strong but it's there. I've had Mitsubishi 6Gs with their usual knackered valve stem seals so I'm familiar with the symptoms of that don't think that's what's going on.

What's the next step, compression test for prognosis and run thicker oil til I can fix it? Still had plenty of poke, very lively little engine. Or is it 13bb time?

[Gwagensteve]

Compression test, but really, just check for blow by out of the rocker cover breather. That's all you need to know.

[TC.Barky]

Nothing visible coming out of the rocker cover breather at idle or revving. Have ordered a PCV valve for good measure as who knows when it was last changed if ever and might do the compression test anyway. Gonna give it a good flush and put some new oil through it and keep an eye on it. Did do a head not long before I bought it.

[TC.Barky]

OK got some time to do the compression test. As below. Thoughts? 330,000kms so definitely expected that it would be getting tired. Guess rings but not crazy bad yet? Still drives very well.

1 2 3 4
D 150 155 170 165
W 180 180 190 190