Club 80-90 Forums

I've just replaced the throttle cable and when starting the engine to check it was all ok, I noticed a tapping/knocking sound that ran in time to the idle and revs.

I've videod it;

http://static.photobucket.com/player.sw ... EO0001.mp4" onclick="window.open(this.href);return false;

And it appears to be coming from the rear of the engine (towards the transmission) . I've booked it in to the garage - a bit beyond me, methinks - but in the meantime, any ideas?

Tappets? Give it a good run for a few miles and see if the noise goes away.

Tony

Hey, yeah, I'd noticed it before once when I'd started it but it disappeared after a while but please excuse my ignorance - what are tappetts and what do they do?

http://carparts.breakeryard.com/cheapca ... ppets.aspx" onclick="window.open(this.href);return false;

. . . or have a play with the search facility on here.

https://club8090.co.uk/forum/viewtopic.p ... it=tappets" onclick="window.open(this.href);return false;

Tony

Thanks. I always do a search b4 hand but as I am am learner, guessed it could be any number of things. But the descriptions of the tappets sound right. I'll still tke it in for the guy to have a look at though.

jamesandhayley wrote:I always do a search b4 hand but as I am am learner, guessed it could be any number of things.

I wasn't being critical, it's very difficult to use the search facility until you've got an idea about what the problem might be. I just meant that there's loads of posts on here about tappets. It's a common problem if a van has been stood idle for a while, needs an oil change or has the wrong oil in it.

I'm still a learner as well.

Tony

Do take it for a run (8 miles - around that) - chances are you won't hear it after that. If you've been doing short runs etc, its common.

Love u guys.

The valves on top of the engine open and close in sequence to allow the petrol/air mixture to enter the combustion chamber and the burnt exhaust gases to exit. These valves have to properly seal each time they close so require a working clearance in order for the valve operating mechanism NOT to hold the valve off it's seat. This clearance used to be manually set with feeler gauges placed between the valve and rocker arm. Back in the early 80's manufacturers slowly replaced manually set tappets for Hydraulic self adjusting types (a tappet ellement that fills up with oil to take out any excess clearance) Trouble is these ellements can become tired and 'leak off' some of their oil when under pressure and stood over night or for several days.
Usually, all they require is a good, reasonably fast run, to get the tappet refilled again.
It might also be worth noting* that many owners have reported an increased occurance of 'noisey tappet syndrome' when thinner, less viscus oils are used. Thinner more modern oils ie: 5W/30, 10W/40, are regarded as being too thin, 15W/40 mineral is recommended, 15W/50 and even older 20W/50 can be used if noisey tappets are a constant issue (thicker oil doesn't tend to leak off as easily).
Change your oil and filter regularly (every 3 -6,000 miles or at least once a year)
Martin

Ive just had exactly this problem and thanks to everyone thats posted here my initial worries have been put to bed

Just been on a 11 mile trip , got back and low and behold the noise has gone. Thank the Lord!

It just goes to prove how useful this site is.

Bonsoir chaps

Thanks for everyone's input - as I said before - love u guys.

Took the van out for a good run today and low and behold, its disappeared (not the van, the tapping).

I'd only done an oil change about 1500 miles ago. It had been parked for a week on a slight camber - could this have caused it? And do I need to get it looked at now I know what it is, or only if it's a recurring problem?

It's not a "problem" it's part of owning a flat four VW...

kevtherev wrote:It's not a "problem" it's part of owning a flat four VW...

Yeah it is normal. The hydralic tappets drain out and they can do this fairly regularly. It is not a problem. Even the Haynes manual refers to this in some detail. The manual suggests using different oil may help, but they point out that this is normal.
Patrick

Thanks again, peeps. Another case of someone just used to modern engines I guess. I had done a Google search on the noisy tappet syndrome and some sites talked of replacing etc, which is why I asked about 'recurring problems', but if she's happy having a little tappetty-tap every now and again, who am I to argue?

jamesandhayley wrote: which is why I asked about 'recurring problems', but if she's happy having a little tappetty-tap every now and again, who am I to argue?

To stop it happening so often regular oil and filter changes for a few times helps.. that means you doing it every 3500 miles.