valves,,how many

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sillysport
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Post Sat Apr 22, 2006 12:16 am

left my car in to get valves set,,came out worse than it went in,,,,dude said could only do six,,,some were to tight to adjust,,,so i want to order adjuster,s for each rocher but dont know how many to order,,she,s going back in to get done again ,want to have new adjusters there for him,,any info would be sound,,cheers
Zayyan
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Post Sat Apr 22, 2006 12:23 am

8. Or 12. Or 16.
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gareth
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Post Sat Apr 22, 2006 12:27 am

too tight to adjust? sounds iffy if you ask me...

does your mechanic know what he's doing? they're really simple when you follow the right procedure. may be worth printing the article in the tech section and taking it for your mechanic to see...

it's also likely you have a worn cam and the valve clearances have been set too close in the past in an attempt to quieten it for resale. you can check this yourself in about an hour with minimal tools required.
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sillysport
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Post Sat Apr 22, 2006 12:28 am

gave him the book,,wit all details on it ,,said that on some of the valves he couldnt get feeler gauge in under ,,,,hard to know,,was going to order new adjusters,,would it even make any odds,,how many would i need to order,,,,325i m20
Last edited by sillysport on Sat Apr 22, 2006 12:35 am, edited 1 time in total.
Zayyan
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Post Sat Apr 22, 2006 12:28 am

sillysport wrote:she,s 325i sport 89 m20,,i believe
That'd be 12 then :)
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sillysport
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Post Sat Apr 22, 2006 12:36 am

nice one,,, cheers mate ,, :D
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Post Sat Apr 22, 2006 12:48 am

you should have another mechanic look at it he mite be trying to make some money out of you, but if you decide to get new rockers you should get 2 rocker shafts aswell because they would of worn with the rockers and also make it noisey
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Post Sat Apr 22, 2006 10:31 am

removing the rocker shafts from the head will be a real pain in the arse unless the head is off. if he couldn't get a feeler gauge in then the gap has been set too tight, probably to quieten a worn valvetrain / cam.

this exploded diagram shows the parts. check the right part numbers before you order anything though as i don't know if they change with the year.
http://www.realoem.com/bmw/showparts.do ... g=11&fg=25

if the cam is worn (1) (likely on a M20) then you'll need a new cam, 12 new rockers (7) and (depending on condition) 2 new rocker shafts (4). if the problem he has is with the actual adjusting mechanism then you can change these easily as they come off the rocker in-situ (8,9,10,11). item 9 is the part of the adjuster mechanism that wears, the others may be needed if they get trashed freeing them up.

one last point, if the cam is worn then change the spraybar (3) as these can block and the cam wears due to lack of oil.

most of these bits are available from gsf.
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Post Sat Apr 22, 2006 2:54 pm

gareth wrote:if the cam is worn (1) (likely on a M20) then you'll need a new cam, 12 new rockers (7) and (depending on condition) 2 new rocker shafts (4). if the problem he has is with the actual adjusting mechanism then you can change these easily as they come off the rocker in-situ (8,9,10,11). item 9 is the part of the adjuster mechanism that wears, the others may be needed if they get trashed freeing them up.
Do you know how much a new head is - and good sources?
My head is a little tappety, if I take it off to replace a few bits one day
I was thinking it might be a lot easier to put a new head on... depending
on cost..
If the cam etc. need changing does the head have to come off?
I'm guessing a new head comes with a cam fitted?
Where is a good source (new) for standard and warmer cams?
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Post Sat Apr 22, 2006 7:54 pm

a new head is silly money and most exchange recon heads are cracked heads that have been welded. if i were you, i'd take the head off and rebuild it as in the guide on this very site.

the M20B25 heads carry a premium as they all crack! i was desperate when mine went (8 month pregnant wife at the time!!!) so i bit the bullet and bought a good used head from a specialist. cost me £200 + vat and i then rebuilt it (takes a sunny afternoon if you have the tools) to make sure all was well. in my case the cam etc was fine.

to FULLY rebuild your head (Assuming the valve gear is all totally shot) with bits from from GSF (all + vat)
head gasket set £43
head bolts £13
cam £70
rockers £8 x 12 = £96
rocker shaft £15 x 2 = £30
rocker adjuster set £3 x 12 = £36
that's £288 + vat. A GSF exchange head is £470 + vat exchange and i don't know if this is fully built and with new valve gear or not...

if you're lucky you won't need more than the cam and a few rockers, that'll only set you back about £160 in bits.

if you do it, you shoud replace the cambelt, idler pully and water pump as they're cheap enough for it to be really daft if you don't!
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Brianmoooore
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Post Sun Apr 23, 2006 11:04 am

Before anyone starts ordering anything, I think we need to find out exactly what the problem is, as the OP is a little vague to say the least.
Martinaston
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Post Sun Apr 23, 2006 11:15 am

If the valves have been re-seated, or are just badly worn the stem's will be longer than when new. when you have them re-seated the stem should have a fraction taken off the top, so if it's not been done correctly it may explain why they are so tight.

If the rockers are worn then it would be easier to get a feeler guage under them, not tighter :?
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sillysport
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Post Mon Apr 24, 2006 1:40 am

well lads this is the story as i was told by the mechanic,,,he done 6 of the tappets,,,there was 1 under inlet manifold he could not get at,,the rest he said were too tight to adjust as he tought he might damage them,,,tight being nut on adjuster was sowed home,,so i ordered new adjusters and bolt,nuts,,,,,,,,,mate is mechanic,,think i will nail him to do the job,,