cylinder pressure

[smegman]

Could anyone help please#? I am trying to find the cylinder pressures for a 2000 2.7 engine. Also can you renew the valve seat/seals on one cylinder only?

 

[Motorhead]

Phillip,

The theoretical value will be atmospheric pressure (14.7psi) x compression ratio (11:1) ~ 160psi. Depending upon mileage, I would think that 130-140psi would be about right. If you're really looking to save costs then I can't think that refacing valves, renewing valve seats, seals and possibly guides on one (offending?) cylinder would be a problem, but it might prove to be a false economy.

Jeff

 

[smegman]

Thanks for that Motorhead. The engine has done 137000 miles with 5 cylinders registering 150 and only number 6 registering 138. I will carry one running it until that fateful day arrives when it has to be done.

 

[Motorhead]

Those values sound pretty solid for a car with that mileage Phil. I think cylinder #6 is one where bore scoring is most prevalent on these engines, so maybe that accounts for the slightly lower pressure value.

I don't know how you conducted the test (hot, cold, looking at pressure drops over time, etc.) but if you inject a little bit of oil into #6 cylinder and run the test again and the pressure increases then that would indicate some bore wear.

Alternatively, as you say you can just forget about what's causing the pressure difference and carry on driving as normal.

Good luck!

Jeff