ozh_hawaiian

how do you know if the valve guides are bad? got a z6 head, and my friend says that I might either have bad valve stem seals, or bad valve guides, but I dont know how to tell if the guides are bad

Corksil

bad valve stem seals or bad valve guides will leak compression out of the compression chamber.

have you done a compression test?

your numbers for each cylinder should be pretty close (within 10%) of eachother for every cylinder.

do compression test, then post up the numbers.

if they are low, try putting a CAP full of motor oil in the sparkplug hole before doing the compression test for that cylinder.

ONLY A CAPFUL. IF YOU DUMP TOO MUCH IN YOU CAN BLOW YOUR HEADGASKET AND THAT'S A MASSIVE JOB. my buddy blew a headgasket like that, and had to work for about 8 hours free and pay for parts out of his own pocket for a customer. not fun.

and if your z6 head is off the block take it to a machine shop and they can pressure test it and check it for warp. Both are smart and easy if the head is just sitting in the garage or somethin.

i'm on maui, reppin Hawaii FTW

if you're on maui, take it to Seki's machine shop on mill st in wailuku (lulz ahahaha it's a machine shop and the street name is MILL st AHAHAHAH)

Corksil

oh minor detail - the reason you put a cap full of motor oil in the sparkplug hole is cuz if your piston rings are worn the oil will act as a seal and raise your compression numbers.

if your compression numbers stay low even with the oil in there- your valvestuffs are probably leaking