Hi my valve guides are worn want to order correct ones. to do it in one evening

the engine codes aau its a 1993 motronic

the valves have an outer of 6.9-7mm

I know the length needs to be 36.5

need internal and external dia.

any help would be great cheers

Edited 9 September, 201412 yr by memadjoe90

First Welcome to the forum.

The only dimension given in the dealers manual is to ream the new guides to 7mm

The test to check for wear is to insert a new inlet valve so the end of the valve is flush with the top of the guide and then rock the valve in any direction and the limit is:- Inlet 1.0mm & exh 1.3mm

Thank you for the info thats basicly how I cheaked them when i did head gasket and lapped the valves in.

The valve seats keep wearing out and causing it to misfire on no.3. This cyl was the one with the worst valve guide wear. They are worn however i dont know what size to order and cant take one out to messure as cars on road all time.

Aparently suppliers say theres a few diff sizes on external dia of the guides and the can pin it down.

my other option is to get a second hand aau 1.05 head and recon that then do a swap over but currently cant find a second hand head.

The guides are not listed in the parts listing

Ok thanks for looking any way

South wales pistons are pretty good look them up online. Give them a call and I'm sure they can supply you with info and parts.

Mate, have you tried looking on vagcat as it often has details of minor part number differences and you may be able to get an exact valve guide part# from looking at your engine/chassis number?

Off the top of my head I found this a while back (I'm taking apart a spare AAV head from a scrappy and was considering putting new guides/seals/tappets in if needed):

http://www.bgautomotive.co.uk/bgacat/partsrch.asp?buyerguide=true&manuid=216&manudesc=Volkswagen&modeldesc=Polo&modelseriesid=338&vehicleui=19314&engine=AAU&enginesize=1&year=1991&endyr=1994

which has length/OD/ID and chassis number details, might be of use.

To state the obvious do you think that the guides are worn through normal use/aging? Rest of valvetrain is OK, no stems bent or sealing faces of valve eroded etc?

Good luck!

cheers people but I'm just going for second hand head, so i can re build that then straight swap cant risk not having the car.

I think the guide wear is just poor metal, or something to do with the misfire from the distributor fault it had on the same cyl.

since it is always in used i drove it with a misfire for a while. This probbly caused late ingition timing burnt valve seat and soften the guide material or something since the problem cylinder is the most worn. The valve from this cyl has an even bronze residue on the stem.

Before this issue had oil change for castrol 10/40 oil i wont be using that again just to be safe. Also oil pump couldent cause this could it? its whiney on start but not played up.

I'm confident new guides and a new valve on problem cyl would fix it. but if I'm swaping for second hand head i may aswell just re build it fully the new one.

Engine has slight piston slap but i recon that will be fine for a long time. Its only done 40000 miles