Valve clearance - all but 2 valves too tight!
Posted: Mon Jul 15, 2013 10:40 am
I just got through with a valve clearance check.
On the intake side, valves in cylinders 1 and 3 were all too tight to measure (less than 0.0015" - my smallest feeler gauge). Cylinders 2 and 4 each had one intake valve at between 0.004" and 0.005", while the other intake valve in each of those cylinders was again tighter than my smallest feeler gauge.
On the exhaust side, both valves in cylinders 1, 2, and 3 were right around 0.005". In cylinder 4, both exhaust valves were right around 0.007".
I checked compression on 1 and 2 earlier today, and got 58psi and 54psi respectively. I squirted about 1ml of oil (using a syringe) in cylinder 1, and got an increase to about 88psi. In cylinder 2, I tried a bit less oil (about 0.5ml) and saw a jump to about 64psi. I didn't bother checking 3 and 4 at that point, and just got started checking the valves. So much for the previous owner's claim that valve clearance had been checked recently. On to the questions:
1. Can anyone tell me if the extremely tight valve clearances are likely to be the main cause of the low compression? Or, am I likely seeing some cylinder blow-by as well? I've read a few conflicting opinions about using the oil in the cylinders trick to check the rings. I wonder if I put enough oil in cylinder 1 to actually help seal up the valves, while putting a smaller amount in cylinder 2 had less of an impact.
2. Are these obviously neglected valves likely to be totally shot, or is it worth experimenting with changing shims (might have to try a few given that 6 of the intake valves were too tight to measure).
On the intake side, valves in cylinders 1 and 3 were all too tight to measure (less than 0.0015" - my smallest feeler gauge). Cylinders 2 and 4 each had one intake valve at between 0.004" and 0.005", while the other intake valve in each of those cylinders was again tighter than my smallest feeler gauge.
On the exhaust side, both valves in cylinders 1, 2, and 3 were right around 0.005". In cylinder 4, both exhaust valves were right around 0.007".
I checked compression on 1 and 2 earlier today, and got 58psi and 54psi respectively. I squirted about 1ml of oil (using a syringe) in cylinder 1, and got an increase to about 88psi. In cylinder 2, I tried a bit less oil (about 0.5ml) and saw a jump to about 64psi. I didn't bother checking 3 and 4 at that point, and just got started checking the valves. So much for the previous owner's claim that valve clearance had been checked recently. On to the questions:
1. Can anyone tell me if the extremely tight valve clearances are likely to be the main cause of the low compression? Or, am I likely seeing some cylinder blow-by as well? I've read a few conflicting opinions about using the oil in the cylinders trick to check the rings. I wonder if I put enough oil in cylinder 1 to actually help seal up the valves, while putting a smaller amount in cylinder 2 had less of an impact.
2. Are these obviously neglected valves likely to be totally shot, or is it worth experimenting with changing shims (might have to try a few given that 6 of the intake valves were too tight to measure).