valve stems

[Karan]

mods please move this to the tech section if this is the wrong place...

my 2.7 smokes on high rpm gear changes and ive been reliably informed the valve stem seals are buggered! prob due to the aggressive cam, and she's eating a litre every 1000mls.

i'll prob do it myself, but does anyone have any idea how much this would cost to get done by a good garage... as i guess they would take less time than i would to do it!

also if someone could give me an idea of the parts cost for headsets and stem seals that would be great.

If i do ot myself and strip the head.. is the standard procedure to get it checked by a machine shop and skimmed if necessary??

cheers
Karan

[Turbo-Brown]

Not sure that an agressive cam would accelerate the wear in the oil seals TBH, but they do wear out in time.

No idea how much it'd cost to get done, although it's a head off job

My 325i didn't smoke too badly, but when I took the head off, all the valves were a bit wobbly in the guides so that's probably worth checking.

Definately worth having the head checked for flatness etc and having a skim taken off if necessary.

It's actually quite a pleasant job taking these heads apart compared to some, why pay someone else to do what you can probably make a better job of yourself!

[Jimbob]

Hiya Karan, can't help on the labour costs but my head set which included everything you'll need cost me Ԛ£40.

[Karan]

cheers

yeh id rather do it myself...

jim does that include all gaskets like inlet/manifold/headgasket--thought it would be more than that-i was sure it was over Ԛ£100, or maybe thats from the dealer???

cheers
Karan

[Toby_Unna]

Karan, only my opinion and i'm not saying the guy who told you is wrong...

but i would be surprised if valve stem seals alone could cause oil consumption that high. i've had cars with buggered valve stem seals (eg my old 528i by the time i'd finished with it ) and the sympton is lots of smoke but little actual oil usage. I'd say your oil usage is more the general state/design of the engine, and not necessarily a bad thing, if oil's being used then it's doing its job in protecting the engine!

buggered stem seals typically cause smoke first thing when you start the car from cold, and also on the overrun - drive at high rpm in 3rd or 4th on a dual carrigeway, then back off and let the car slow down a bit with the throttle closed, then come back on the gas and look for smoke.

[Jhonno]

she's eating a litre every 1000mls

im pretty sure Renault call that normal oil usage...

[Karan]

Karan, only my opinion and i'm not saying the guy who told you is wrong...

but i would be surprised if valve stem seals alone could cause oil consumption that high. i've had cars with buggered valve stem seals (eg my old 528i by the time i'd finished with it ) and the sympton is lots of smoke but little actual oil usage. I'd say your oil usage is more the general state/design of the engine, and not necessarily a bad thing, if oil's being used then it's doing its job in protecting the engine!

buggered stem seals typically cause smoke first thing when you start the car from cold, and also on the overrun - drive at high rpm in 3rd or 4th on a dual carrigeway, then back off and let the car slow down a bit with the throttle closed, then come back on the gas and look for smoke.

cheers toby...

its eating about .8litres every 1000mls mainly mway driving at over 4k rpm

it only ever smokes on overrun as u describe im pretty sure its valve stem seals, although i do know the m20s tend to eat a bit of oil , however my engine has done 80k miles-i change oil every 3k miles, but it has been driven hard with track days

i suspect if i rebuild the head the oil consumption will reduce, its just the smoke that pisses me off on the overrun above 5.5k rpm that pisses me off to be honest, i dont expect oil consumption to disappear just reduce. oh and the compression is fine as i had it tested, so its defo the stem seals. i get what u mean though regarding consumption

cheers mate

Karan

[Jimbob]

Yea that set I bought included everything accompanying the head, I didn't pay VAT and in weighed in at Ԛ£40.

[Zerotonine]

A litre every 1000 miles.... My old Cavalier burned 5 litres every 300 miles! and it wasn't dropping any...