Hiya, I'm advising this guy with a newly rebuilt engine that suddenly started running like crap after 10k miles. I believe it's a '75 bus.
He tells me that #3 valve is un-adjustable - he is unable to tighten down the set screw enough to make contact with the valve.
I am guessing a mushroomed adjuster head, a sunken valve seat, or rocker issues. Lifter maybe? You guys have any advice?
Valve Adjustment - Type 4
- hambone
- Post-Industrial Non-Secular Mennonite
- Location: Portland, Ore.
- Status: Offline
Valve Adjustment - Type 4
http://greencascadia.blogspot.com
http://pdxvolksfolks.blogspot.com
it balances on your head just like a mattress balances on a bottle of wine
your brand new leopard skin pillbox hat
http://pdxvolksfolks.blogspot.com
it balances on your head just like a mattress balances on a bottle of wine
your brand new leopard skin pillbox hat
- SlowLane
- IAC Addict!
- Location: Livermore, CA
- Status: Offline
Re: Valve Adjustment - Type 4
My guess: something blocking the valve open. Possibly (probably) a dropped valve seat.
Get in there with a good light and inspect/compare the installed heights of all the valves on that head. See if the culprit valve is further in (less height) than the other three. Remove rocker arms if necessary to get a clearer picture.
If that's the problem, shine a light down the spark plug hole and see if you can spot what's holding the valve open.
Free advice: worth every penny.
Get in there with a good light and inspect/compare the installed heights of all the valves on that head. See if the culprit valve is further in (less height) than the other three. Remove rocker arms if necessary to get a clearer picture.
If that's the problem, shine a light down the spark plug hole and see if you can spot what's holding the valve open.
Free advice: worth every penny.
'81 Canadian Westfalia (2.0L, manual), now Californiated
"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett
"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett
- Amskeptic
- IAC "Help Desk"
- Status: Offline
Re: Valve Adjustment - Type 4
Call the rebuilder.hambone wrote:Hiya, I'm advising this guy with a newly rebuilt engine that suddenly started running like crap after 10k miles. You guys have any advice?
Follow slowlane's advice. Do not crank the engine. Do not start the engine. A valve adjuster that cannot reach the valve stem is much less likely to be the usual litany of overheat symptoms that cause recession where you cannot back out the adjuster far enough to get clearance.
Do not rotate the engine into any resistance!
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles
- hambone
- Post-Industrial Non-Secular Mennonite
- Location: Portland, Ore.
- Status: Offline
Re: Valve Adjustment - Type 4
Thanks guys.
http://greencascadia.blogspot.com
http://pdxvolksfolks.blogspot.com
it balances on your head just like a mattress balances on a bottle of wine
your brand new leopard skin pillbox hat
http://pdxvolksfolks.blogspot.com
it balances on your head just like a mattress balances on a bottle of wine
your brand new leopard skin pillbox hat