Timing chains and tensioners question

[matth76 0]

Hi

 

I recently had my timing chains and tensioners done. I found out afterwards the garage had only replaced my upper timing chain and all upper chain tensioners and everything to do with only the upper chain (including all guide rails etc). The bottom chain was not replaced nor any of its tensioners etc. I was told that the bottom chain and its tensioners never need replacing as they are much tougher.

 

Is this true? Who else has had their chains done - did the garage replace anything to do with your bottom chain (i.e any of the bottom chain tensioners etc)?

 

Thanks for any help.

 

Matt

[joebloggsVR69 0]

Hi

 

It is usually the top guide rail that wears down, so in a way, the mechanic was telling the truth. But if he's gone to the trouble of changing one chain/guide rail, then it would have been better to replace the bottom one too, just for peace of mind. (And the clutch too :wink:)

 

I got my top and bottom chains done. But I supplied all the parts, and specified exactly what I wanted doing

 

Like I said, I've never heard of the bottom pad wearing away like the top one, so it's probably not worth losing sleep over it :)

[matth76 0]

Thanks. The only thing that bothers me is that I have a flat spot remaining after the work was done just under 2000 revs. Some people have mentioned this could be because the cam timing is not quite right due to the fact I've only had the upper chain done and not the bottom one. I wasn't sure whether it was usual practice for the bottom chain to be done as well as the upper one. I agree seems strange they wouldn't change it while the gear box was out however being the lamen I assumed the garage was right in what they said and that the bottom one would never normally need replacing in the lifetime of the car.

 

Could a faulty cam sender wheel be the cause of my flat spot? How easy is this to replace - is it a lengthy (i.e more than 3 hours) job?

[andy 0]

Its pretty unheard of imo to replace only the top timing chain parts, if you go to the hassle of taking the gearbox off etc to change the top chains/tensioners then it just seems silly not to replace the lower chain parts. I changed mine last year and whilst there was no obvious wear on the lower parts, it was about a £100 for all the lower chain parts genuine VW. There was no visible wear on the clutch either but for a further £100 I had a genuine VW clutch in. The car runs like a dream. Its just not worth taking that much apart and not replacing things imo. It would be like reconditioning a cylinder head and putting old spark plugs back in, you just wouldn't do it.

[Supercharged 2]

Could a faulty cam sender wheel be the cause of my flat spot? How easy is this to replace - is it a lengthy (i.e more than 3 hours) job?

 

Less than 3 for a competent garage i'd say, obviuosly does take time tho as the manifold and cam cover need to come off so there is a fair amount of stuff to strip down and build back up again, have you had different cams put in?? I ask because the wheel would normally only break if the cam pulley had been off which it wouldn't if you just had the chains done...

[matth76 0]

No I've not had any new cams put in. I only asked as another forum mentioned my flat spot could be because the cam sender wheel was damaged when they had to take of the sprocket of the cams to do the chains. Should the cam sender wheel be replaced when chains are done? I've heard they are prone to breaking.

[Kevin Bacon 5]

For the sake of £7 it is definitely worth changing the trigger wheel. The sprocket bolts are torqued to 100nm and the plastic outer part of trigger wheel tends to crack.

[andy 0]

I've never changed one and had no problems, didn't realise they were only £7 though!

[Supercharged 2]

I think Kev means when changing cams - not normally done on a timing chain job...

[andy 0]

I think Kev means when changing cams - not normally done on a timing chain job...

Good point that man!

[matth76 0]

Thanks for your replies guys. It could be very possible that they removed my top timing chain without removing the gear box. I was having the head gasket done at the same time so they could have had access to the top chain with the head off. To have a head gasket done and top timing chain cost me £650 which still seems good considering a head gasket replacement on its own is normally around £400-£500. If they had taken the gear box out then I certainly agree it wouldn't make sense not replacing parts for the bottom chain.

 

I suspect my flat spot is down to the fuelling air mixture as they did adjust my fuelling when they had my car in. They had to reduce it slightly as my car was overfuelling. I suspect they reduced it a tiny bit too much. My car is going back in with them anyway to have the head gasket bolts tightened and to check for any oil leaks as I have done the routine 500 miles since having it fitted so will get them to re-adjust the fuelling. I'll be there while they do all the work so will take it for a test drive to see if it eliminates the flat spot. I think it seems too much of a coincidence that they reduced my fuelling and after I pick my car up there is a flat spot in a certain rev range and it is a tiny bit lumpy too in the low revs when I pull off from a roundabout.

 

Following all this (if successfull!) I'll be getting a full remap at Stealth to get the most out of my mods!

[andy 0]

It could be very possible that they removed my top timing chain without removing the gear box. I was having the head gasket done at the same time so they could have had access to the top chain with the head off.

Nope. You can't change the chain without getting the gearbox off. This is the point. Even with the head off.

How exactly did they adjust your fuelling???

[Trig 0]

Fueling and other stuff already discussed here:- http://www.the-corrado.net/.archive/forum/viewtopic.php?t=34464

[PhatVR6 0]

sounds like you literally got half a job there.

 

and it also sounds like the cam timing is out too.

[andy 0]

Fueling and other stuff already discussed here:- http://www.the-corrado.net/.archive/forum/viewtopic.php?t=34464

Yep, discussed but not answered by the looks! Its not possible to adjust the fuelling is it.....hmmm

 

Agree with Phat, sounds like the Cam Timing is out, thought that from the start. I think Matts confidence in Storm or whoever they are is misplaced, sounds like a clusterf*ck to me.

[Trig 0]

It was answered, they replaced the lambda probe.

[andy 0]

It was answered, they replaced the lambda probe.

 

Hmm. Kind of. There's a lot of talk in this thread about adjusting and readjusting fueling. See Matts last post. If they have replaced the Lambda sensor then it should be ok now. There isn't any adjustment beyond the Lambda sensor and the ECU...is there.

[andy 0]

I suspect my flat spot is down to the fuelling air mixture as they did adjust my fuelling when they had my car in. They had to reduce it slightly as my car was overfuelling. I suspect they reduced it a tiny bit too much. My car is going back in with them anyway to have the head gasket bolts tightened and to check for any oil leaks as I have done the routine 500 miles since having it fitted so will get them to re-adjust the fuelling. I'll be there while they do all the work so will take it for a test drive to see if it eliminates the flat spot. I think it seems too much of a coincidence that they reduced my fuelling and after I pick my car up there is a flat spot in a certain rev range and it is a tiny bit lumpy too in the low revs when I pull off from a roundabout.

 

see what I mean?

[Trig 0]

Well what he is saying is wrong, you can't adjust the fueling too much etc., it's either right or wrong... quote from other post:-

Thanks for your replies. Yes I had a problem with my lamda (showed up on VAG COM) which I assume also showed up the over fuelling fault. They replaced the lamda sensor and the fault was corrected.

 

Anyway, we're talking about chains & tensioners now. :)

[andy 0]

Indeedy :-) I can see some incorrect up-tree barking going on here thats all!

[Roger Blassberg 0]

Could the flat spot be due to a cracked coil pack?

 

Happy New Year!

 

RB

[matth76 0]

Hi everyone, thanks for all the replies. Right, I phoned Stealth today and have booked my car in. They too were very surprised the bottom chain and it's parts weren't replaced. All in all I'm not going back to the garage again. They may well be good but they should have done the bottom chain as well (or at least have told me before hand that one of the chains wasn't going to be done!). Their mistake is now costing me £600.

 

Stealth couldn't understand why on earth the bottom chain and its parts weren't done when the gearbox was out... nor can I!! Vince also said the bottom chain is actually more prone to breaking than the top one due to it being thinner - although it is very rare for it to break he said. Vince didn't know what the flat spot was due to but they are going to do my bottom chain and all its parts plus new clutch and check over my car and new s/s exhaust manifold that Storm fitted... just to make sure everything else is in order and to fix my flat spot and that the top chain that the garage fitted and all it's parts are new. Also getting it rolling roaded. Costing me £616 all in (inc. vat)... which hurts but is going to be worth it to have my car back to how it was and with the knowledge the chains are now 'completely' done.

[matth76 0]

Would there be a way for Stealth to check that the head gasket was properly sealed without taking it all apart? Is this what a compression test would show? The last thing I need is a head gasket blowing 6 months down the road.

 

By the way before Storm did the work I had no idea they were only replacing one of the chains. I only found out AFTER I got the invoice and it said top timing chain. As far as I was concerned they were "doing my timing chains" which I 'assumed' would be all of the chains.

 

Is there some kind of body I can contact to 'get' them to do the bottom timing chain free of labour BECAUSE they should have done it in the first place?? Or will it come to nothing? From my understanding Trading Standards aren't helpful in these cases? Is there a similar body that I can contact for info on this?

[Kevin Bacon 5]

If there are no visible leaks from the gasket they won't be able to do much other than lift the head to check it. They might be able to do a leak down test on it though. Speak to Vince when you're there.

 

If Storm billed you for the complete timing chain set and only replaced the upper one then you can claim, but if they only replaced what they billed you for then there's not much you can do unfortunately.

 

You might be able to come to some 'arrangement' being as it's needless repeat labour though. Best speak to Storm about that.

[matth76 0]

Before the work was carried out it was word of mouth (which is useless I know) where they said they would do the chains. This I took meant they would be doing all of them (as most garages I have since found out do do). When they handed me the invoice after the work was done it initially only said "head gasket and tensioners set" which they told me included timing chains. I asked them to actually write on the invoice that this included timing chains as it was a bit vague and I would need it clear for when I sell the car in the future one day. It was then that they put only "top timing chain". I asked them about this (bear in mind I am a lamen and don't know a lot about timing chains - at least I didn't then) and they said the bottom one and its tensioners never need doing as they're much tougher. I (as would any customer) assumed they are right..being the garage. It is only after I have paid them, gotten home and rung around and found out that the normal/common course of action IS to do the parts related to the bottom chain as well as the top (especially if the gearbox has come out). I am going to attempt to get them to fit the parts for the bottom chain (I will pay for the parts of course) but the labour should be free. Then I will get Stealth to check over everything. However I suspect they will be unwilling to do it for free labour. Either way I'm taking it to Stealth to check it all. In a way I'm reluctant to let them near my car again - even though it will cost me £600 (which does include a new clutch and rolling road) I would rather Stealth did the remaining bottom chain and have a good look at the top chain and the parts Storm fitted.

 

What is a leak down test on the head gasket? I'm assuming "lifting the head" to check the head gasket is a lengthy process?

 

What a hassle! I only wish I had known more about what is involved in replacing timing chains and what parts are replaced.