howdie all, i just got back from doing a compression test with scotty (zweet) and we found some interesting figures... on the drivers side, listed from front of the car to the firewall, we got 180psi, 172psi, 180psi on the passenger side we got 140psi, 165psi and 160psi now this is significantly lower than expected. the engine was rebuild about 3000km ago and there was some talk that i would need to retighten the head bolts (after a rebuild) is this true? the car is also blowing white smoke, its not oil or fuel, so we are presuming coolant..... any ideas? do i need to replace the head gasket? cheers
The passenger side gasket on 2 4 6 cylinders, is down on comp, number 2 is real low and possibly where the gasket is damaged. theres no point in retensioning it now, but i would check the tension on the studs just to see if that was the problem, before i pulled the head. Retensioning the heads after a rebuild is the norm, or it used be, but i wounder how many would do that on a Zed.
Pinging? Coolant leaking into the cylinders can cause the engine to ping. So, if your car is pinging, good chance you have blown a head gasket. Lance
Re: The passenger side gasket on ACL swears against retensioning head bolts.. i do it anyway.. i had one fail without retensioning
just don't jump in til you're confident of what it is.. head gasket's tend to show low compression on 2 adjacent cylinders. How did your plugs look? What were your numbers after adding some oil? Did you get a hydrocarbon test? are you seeing bubbles in the radiator or any coolant in the oil? Is it only blowing smoke from the low compression side? If you have an X or H pipe, maybe drop the exhaust after the cats to check. I'd try a leak down test too.
Re: just don't jump in im about to do a coolant system pressure test and a leak down test, the coolant looks normal and the oil is normal, after i get these things done, ill figure out whether its gasket only or also valves and or rings, lets just pray for the best..... plugs were replaced with NGKs and they are normal after about 500kms and its not pinging if it is heads, ill do a tech article for it as there doesnt seem to be one yet cheers
