Tappet noise? ---vr6

[peanut 0]

Right, rebuilt a 12v vr lump a couple of mths ago. New rings, rest of bottom end in excellent order so nothing else replaced on that.

Head was rebuilt, new valve guides, exhaust valves, stem seals and tappets. New upper chain and plastic tensioner. Bolted it all back together and it rattled like a sticking hyd tappet, ran it for a few hundred miles on mineral then oil and filter change for synta silver. Still got the tappety noise. Seems to go away at higher revs but other that that its not cleared once. Other than a fecked new tappet any ideas? here are the possibilities ive thought-

- shaged tappet

- Blocked oil way (but where?)

- Silicon residue blocking the oil way on the upper chain cover (from where the upper cover meets the lower cover)

- Rear tesnioner (the big bolt that screws into the back off the head) needs replaced? its the original one

 

Tired wynnes etc but made no difference, am i missing something obvious? dont really want to put the original tappets back in as one was sticking slightly and im not sure which one.

 

Cheers for any help

Gav

[mtc R32 0]

Have yo tried replacing the tired oil pump....? Normally the culprit :roll:

[dr_mat 0]

Woz gonna say, you checked the oil pressures?

[M15 VW 0]

Woz gonna say, you checked the oil pressures?

 

It is the original pump as far as I know, it wasn't replaced in the rebuild. However, didnt have this problem before we rebuilt it. Oil pressure sender is working fine and the oil pressure light has never come on. Can I remove the oil pressure sender in the oil filter housing and plumb a gauge in to give me an accurate oil pressure reading? Is there anywhere in the head I can tap into to get a reading from?

 

Anybody had any experience of problems with the upper tensioner bolt (that screws into the back of the head)?

 

Thanks for your help.

[dr_mat 0]

Anybody had any experience of problems with the upper tensioner bolt (that screws into the back of the head)?

 

Did you pre-pressurise the tensioner bolt? I've heard of one or two people say they've had DOA ones of these, they won't hold pressure.

[M15 VW 0]

We followed the instructions in the bentley manual but are not convinced 100% we have done it properly. Going to take the one off of Gavs's vr and try that. At least we will know either way if it makes a diference.

[M15 VW 0]

hmm....the tensioner bolt off gavs rado made no difference. It is booked in for an oil pressure test today so we will see what that says.

[M15 VW 0]

Didnt have time to get it tested but we were given the kit to do it ourselves.

[fla 9]

Where did you test the pressure - from the sensor or at the head? If the latter could you let me know exactly where? Thanks.

[M15 VW 0]

Hmm, right we have found the cause of this..........finally. It is the upper chain tensioner.

 

This has already been replaced once when the head gasket was done. (Before the rebuild)

 

However, it looks like the tip of the upper chain tensioner has snapped off due to wear and there are two deep grooves in the tensioner itself where the chain has been rubbing against it (very deep, almost past the rivets).

 

Any ideas on how this could have happened? Could the upper tensioning bolt be putting too much pressure on the tensioner pad? The chains were brand new when we rebuilt it and the upper tensioner pad was replaced a couple months previous to that and was fine on inspection during the rebuild. The only thing not to have been replaced was the upper tensioning bolt. Could this be the culprit for the damage or is there something else we should be looking at?

 

Also, is there any way of sliding the upper tensioning pad off without completly removing the gearbox?

[steve @ 0]

I had this problem with mine when the bolt tensioner got a little bit of crap in it blocking the oil way, this resulted in chewing the top pad up. By the way if you want another top pad (original metal with polymer layer and rivets) I have a brand new one you can have for free.

[M15 VW 0]

I had this problem with mine when the bolt tensioner got a little bit of crap in it blocking the oil way, this resulted in chewing the top pad up. By the way if you want another top pad (original metal with polymer layer and rivets) I have a brand new one you can have for free.

 

You are a diamond! Yes please. I will PM you my address details. Thank you.

[M15 VW 0]

Sorry about the blur but this is the best pic we could take of the damage .......

 

[peanut 0]

I had this problem with mine when the bolt tensioner got a little bit of crap in it blocking the oil way, this resulted in chewing the top pad up. By the way if you want another top pad (original metal with polymer layer and rivets) I have a brand new one you can have for free.

 

Out of interest what were your symptoms for inspecting the tensioner pad? Im wondering if i didnt purge the tensioner bolt when i reinstalled it :( leaving air inside, or i over torqued it? would this lead to adverse pressure on the back of the pad or would the damper in the bolt compensate for this?

Bugger is all ive got to say, especially as it looks like it was my fault, Bum :(

Sorry Zed :(

[steve @ 0]

symptoms, it started to wine pretty badly. Then eventually started making a horrible sound. Mine looked pretty much the same as yours. I dropped the sump on mine after to clean the remains of the top pad, i'd recommend you do it as well as there were a few bits floating around..

[M15 VW 0]

right, it's now got a new tensioner bolt and pad. Fired it up and the noise is still there. Going to now change the two chains and bottom tensioner (engine out again!). Any other suggestions? I can't think of anything else to change.

[Kevin Bacon 5]

Did you notice if your cams and tappets look anything like the attached?

 

If they did, you've probably got an oil pressure problem.

 

Have you checked the hot and cold pressures are in spec?

 

Too little pressure and you'll get a bit of starvation up there, which takes the case hardening off the cams.

 

And likewise, too much pressure and the tappets are jammed up to the cams too tightly and it will also chew through your tensioner quite nicely. The engine will also sound and rev as rough as a badger's arse.

 

That's what happened to my cams and tappets over 6K with an oil pressure issue. The MK4 solid upper pad survived though, so I'd recommend you fit one of those if it comes apart again.

[M15 VW 0]

We did have a look and we couldnt see any damage to the cam lobes or tappets. We did take oil pressure readings but dont have them to hand. I recall being quite close to being in spec with the Bentley manual.

[M15 VW 0]

Right, Toad and Peanut have just spent today and yesterday in the wind and rain replacing parts on my corrado, some replaced again since the last effort so they were new and we could rule them out for being the problem. This time the following were replaced: -

 

Upper and lower chains

Lower tensioner

Tensioner bolt and pad were replaced with mk4 24v ones

Clutch lever arm

Lower chain cover oil seal

 

They just fired Zed up and guess what, no rattling!!!! :D

 

We are thinking it was either the tensioner bolt, the lower tensioner or the upper chain that was causing the problem.

 

Just want to say a big thank you to Toad and Peanut for working their arses off this weekend. Appreciate it greatly.

 

I am really pleased this problem has finally been solved.

 

Thanks again guys

[Toad 0]

Really pleased we got it all done and fired up. The rain was starting to worry me a bit this afternoon. Let me know when you get him out for his first run!

[jamminvr6storm 0]

Excellent.... Glad you got it sorted Nikki :D

 

My 2p would have been the tensioner bolt after wearing a pad out in 1000miles :shock:

 

Take it you got an O ring in the end then.... lol

[M15 VW 0]

Excellent.... Glad you got it sorted Nikki :D

 

My 2p would have been the tensioner bolt after wearing a pad out in 1000miles :shock:

 

Take it you got an O ring in the end then.... lol

 

well theres been two rado tensioner bolts on there and then the mk4 24v one which is on there now so who knows lol.

 

How lucky am I?! I went to three or four places yesterday regarding the o ring. One guy directed me to a place on scabby island which shut at 12 so I had half hour to find it lol. I got there and they had 3 o rings in the right size so I got them all. Finding a motor factors open on a sunday with the right size o rings has to be fecking lucky!!!!