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possible worn valve seats

Posted: 08 Jan 2011, 13:33
by elmo makaroy
hi,

i have had a call from the garage who are fixing my 1982 Aircooled cu engine in my camper,

after me thinking that my problems were with the carbs they have looked into it and have found that two of my valves were tightened incorrectly (to tight i believe) and this may have damaged the valve seats and some idiot had fitted incorrect spark plugs,

they have set the valves correctly replaced any worn vacuum and fuel pipes and have road tested the van, but they say that it is still underpowered and not running as it should,

so they done a compression test and have found that cylinder 1 is at 70% cylinder two is at 80% cylinder 3 is at 100% and cylinder 4 is at 90% aparently it is loosing compression through the piston rings wich is causing my problems,


they say that there is also a knocking coming from my engine and are currently in the process of doing some more tests and are going to get back to me later today to let me know the outcome,

i just wanted to know if theese problems are major and how easy it is to fix? and also has anyone else here had similar problems and wot was the outcome, i understand the basics of my problems but i am not a mechanic and it would be great if someone could explain to me more clearly wot all this means?

many thanks

Re: possible worn valve seats

Posted: 08 Jan 2011, 16:11
by elmo makaroy
well i have just heard back from the garage,

basically they have cleaned out and replaced the jets in my carbs and fitted the correct spark plugs and reset the valves as they should be,

the mechanic has said to me that it starts and runs fine but is not as powerfull as it could be and its basically not worth spending the money on repairing the engine as it would cost near as much as it would to just fit a replacment engine,

the other main problem he said i have is that the throttle linkage is completly worn out and so it cannot really be adjusted properly,

so i need to get a new throttle linkage, can i buy this new and is it expensive, also wot are peoples thoughts on replacment engines and wot engines can i fit? or should i just run it as it is untill it goes pop??

the van is a 1982 2.0 Aircooled with a cu engine

im not sure wot to do in the long run to keep my bus going and i have already started gathering up parts for it so i dont wanna give up

Re: possible worn valve seats

Posted: 08 Jan 2011, 21:04
by jason k
does your mechanic realise the lifters are hydraulic and not solid lifters?

how did he set them? as overtight valves will give "pooh" compression readings

Re: possible worn valve seats

Posted: 08 Jan 2011, 21:26
by ..lee..
tappets too tight now set tapping noise. jase is on to something i think??

Re: possible worn valve seats

Posted: 09 Jan 2011, 09:19
by jason k
if you fill in your location perhaps we can reccomend someone tidy to take your van to as most garages have no idea what they are doing with these flat fours

Re: possible worn valve seats

Posted: 09 Jan 2011, 12:29
by elmo makaroy
tappets too tight now set tapping noise. jase is on to something i think??

i dont get wot you are saying here,

i am in the essex area i have just found a place called harry harpics who are supposed to be good who i am now thinking of going to, the thing is the garage who currently have the van are called vw down under and are actually a vw camper specialist,

i think he adjusted the tappets and then done a compression test and the results were poor but better than it was origionally before he adjusted them

Re: possible worn valve seats

Posted: 09 Jan 2011, 16:35
by kevtherev
There are two types of tappets... Solid and hydraulic
your engine has hydraulic
and if you adjust hydraulic tappets to solid values then the engine will sound terrible.

New heads are cheaper than a new engine
your engine has a long heritage there are msny many outlets for this sort of stuff

Re: possible worn valve seats

Posted: 09 Jan 2011, 19:05
by jason k
vw down under works on bays which mainly have solids. he may not be aware whats in your motor, the very same happened to me with my type 4 motor years ago.

if the tappets for a hydraulic type are set as solids then the gap will be wrong allowing poor compression and poor running.

ask him how he set them?

feeler gauge or preload and back off

that will tell you whats been done

Re: possible worn valve seats

Posted: 09 Jan 2011, 23:07
by kevtherev
elmo makaroy wrote:surely a vw camper specialist would of known that the tappets are hydraulic, wouldnt he? i dont understand wot makes you guys think that he has set the tappets wrong?

Because we've heard this many times, my friend , too many to not ask the question.
We're not saying he has got it wrong, we're simply asking if he is aware that t25 cu's are hydraulic