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Andystewart

The great tappet debate!

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Evening lovely people out there. So just after a bit on confirmation. So after a top end rebuild, consisting of, valves, guides, seals, top and bottom chains kit, and good clean obviously, I have what sounds like a noisy tappet, not these are the only part I didn't change in the head as everywhere I read said, clean them thoroughly and reinstall. So I assume this to be my problem, I can hear the tick from rear left (drivers side) and also if I listen through the oil cap hole. but.... I ran the up to temp this eve with a good thrashing and rapidly stripped the manifold and Cam cover off (took me prob 10mins max) to see if any tappets not holding pressure, all "seemed" solid. Is this still likely my cause? Other forum suggestions, are cracked exhaust manifold, but it didn't make this noise when first rebuilt and run, it's appeared recently (200miles since rebuild) also wouldn't this get quieter when everything is super hot if cracked Mani?

Chain is tight but not over tight, tension or looks good. Everything thing was covered in oil and flicking out oil cap when running so assume OK pump is doing it job, as no oil pressure lights!?

Just want some one to agree it's most likely tappets as the only thing not replaced! I seem to recall a slight tapping before rebuikd but thought a tappets strip down and clean would cure??

 

Thanks in advance people.

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What oil are you using if it's too thick could greatly increase the sound of the tappets.

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Using 10w40, at the moment, thought about changing for 10w50 or 60 as per some threads but if this works will it not simply mask the sound rather than solve it?

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Did you replace the aux belt tensioner or bearing? This can be quite noisy. To be honest, a VR will be quite noisy until it warms up, and I've replaced tappets on quite a few other engines, and except in one case they never made quite as much difference before and after as you would expect. I think we tend to compare with newer cars that have a lot more insulation and sound proofing.

 

10-40 is semi-synth is the correct grade of oil. Have you checked oil pressure and the pump pickup?

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Hi, no didn't do belt tensioner, as felt OK when I had it off. I can hear the tappets more distinctintly when I listen through the oil filler cap which adds to my suspicions. I haven't checked the oil pump properly with a tester, while it was off I took it apart cleaned it up tested in some oil with a drill, and it seemed ok, as I wasn't able to hold the pressure back very well with thumb over the hole. Suppose this isn't a acurate test method so could still be a culprit. What's the chances of a knackered tappet, even after cleaning?

Am in thinking a cracked manifold woukd get quieter when hot?

The tapping noise doesn't disappear when hot, or after long run, and there is plenty of oil around the head so the oil is there.......

It seems to loud to be the expected vr6 tapping.... This car is costing me a fortune and destroying my love for it!

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You could slip the belt off for a trial for 10 seconds or so, I'd do it with oil temps no higher that 60 degrees though.

 

I presume the heads been skimmed? And the valve seats cut too to restore clearance between the valve heads and pistons?

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Yeah, will try with the belt off. Head only required a very very minimal skim to be certain, he said it didn't really need it but I had it done as I didn't want to go through all the effort and it cause a problem and machine shop said it would be fine just lapping new valves.

It ran sweet when first run after rebuild, but recently started tapping so no concerns over valve clearance, also wouldn't the valve cut outs in the piston accommodate the minimal thickness removed after a skim? I'm not concerned this is the problem as ran quiet after rebuild.

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I'd be inclined to say its a tappet, when I did the chains on mine I took all the tappets out and compressed them all in a vice to flush all the oil out. Soaked them in oil overnight then refitted them. They tap like crazy for about 20 minutes then go absolutely silent.

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Have you read the thread from VW Chris about his tappet issue that he solved. Well worth a read with what his problem was.

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Using 10w40, at the moment, thought about changing for 10w50 or 60 as per some threads but if this works will it not simply mask the sound rather than solve it?

 

You would want thinner oil, not thicker. I would try some Seafoam in the engine (or similar UK product), or ATF, run it for 100 miles, and then switch to a 5-40 type of oil and see if you notice a difference. You might have a bad spring in one, thus would need replacement. Some have used Rislone engine treatment with some success but I have no experience with it.

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I haven't read the thread, anyone able to post a link? So I have a new set of tappets arriving tomorrow, oem INA one. So will swap these in and hope and pray.....

Thanks

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I dont have the link, but he does mention the INA tappets. Not necessarily in a good way. Search for vr6 tappety sorted... sorry I now can't sort the link

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New tappets arrived today...yay. but.....they are solid! I can't press the piston down by hand, so, should i fit as is, or press them in the vice to remove some of the lube? Should they be fitted virtually empty of oil so they can self adjust and fill up or will they still self adjust if they feel solid?

Rhanks

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It's my belief, thus far not proven, that the intermediate drive shaft for the oil pump is the cause for a lot of the regular tapping noises on old VWs. It's the one thing that's never replaced during timing chain replacements, and replacing tappets all day long doesn't ever seem to make it completely go away.

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Hi, well, to disprove you beliefs, the reason for my rebuild was because of a worn intermediate shaft bearing, this caused the chain guides to wear and the chain to jump meaning it bent a valve on every cylinder, so, I had to have a sleeve pressed into the block, and a new bearing and shaft installed so I'm 100% confident this is not the issue here. Last night I replaced all the tappets, found 2 with very very slight play, Bentley manual states anything more that 0.1mm is shagged. The engine is so so much better and quieter but there are still some taps coming from somewhere, and she taps more at about 2k revs. Think I'll swap out for a new pump as that now the only thing I can think of now. I blew the oil ways through and they were all clear. Check pulleys and manifold and all looked/ felt good.

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