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Sticking Valve

bettley91

bettley91

Messages
18
Any body have any experience with valves sticking?

i have done a compression test and one cylinder is down on pressure, i know it isnt the piston rings so i can only assume its a valve sticking open. Does anybody know of any ways of treating this as i really don't want to take the head off?

Many thanks
 
You need to do a leakdown test to establish if it's sticking or just not seating correctly.

How do you know the rings/bores are OK?
 
put oil down the bores and did it again and no change in the compression. Also if there was pressure in the crankcase it would surely throw a oil pressure warning of some sort?
 
What values did you see? How much lower was cylinder 1?

You're right, it would if it was really bad. It'd also be burning a lot of oil if the rings weren't sealing correctly, is this the case? I'd expect a lumpy idle & power delivery from a sticking valve.

What symptoms did you get to prompt a compression test?
 
i cant remember the exact pressure but it was half of the first cylinder. not burning any oil at all,

the engine management light came on and threw up a low compression in cylinder No2 fault code,

i then changed all the plugs put some injector cleaner and changed the coil packs around to try and budge it but t o no avail.

yes the idle is lumpy but the power delivery is fine.

Cheers
 
The engine has no compression sensor so you got the code wrong.


Time to rip the rocker off and inspect the valve train and then the head if need be .

I'd say it's not stuck it's burnt .
 
Get the head off and go from there mate. It's going to be one of those things that you don't know until you can look at it and asses the situation. You could suggest a few things but until the heads off you just don't know. How do you know it's not the piston rings causing low compression?
 
Not yet as it drives okay but I think the head will be coming off over the next fortnight, I will keep you posted
 
I've got the same as this
came up with misfire code on cylinder 3 and 4 just had compression test and all cylinders read 150 apart from number 3 which is reading 90.going to try some flush next weekend.
so interested to see what you find .
 
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