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Old 02-19-2021, 08:17 AM
ukvolvo ukvolvo is offline
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Default Fix for noisey tappets?

As the title states does anyone know of a fix for noisy tappets or is it new tappets and tough luck.

My engine is a 95 so they are hydraulic arent they? I am guessing all the products are a load of rubbish and if their worn their worn.

Noisey tappets drive me wild and sadly good oil has not helped.

Thanks
Mick
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Old 02-20-2021, 12:38 AM
jpliddy jpliddy is offline
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Default 940 TIC auto 1995

hi
are you 100% sure the note is just the tappets ,the main culprit on these engines is the vacuum pump i know that as i changed mine eventually , and met other who have too . made a vast difference only mistake was i bought the feb brand which has a slight oil weep now ,wish i had spent the extra and got the genuine PIEBURG as thats original equipment . easy job if its that ,just make sure the cam is at TDC on injection pump it releases pressure on the spring and the plunger goes back the same way as it came out end to end, there are bulletins on it on the internet .as we know these engines renowned for being noisy especially when cold .
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Old 02-20-2021, 01:44 AM
ukvolvo ukvolvo is offline
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As far as ive guessed its tappets. It could well be the pump on closer inspection.

Would i notice a difference if i did a ear test (long stick in ear to hear vibrations in effect) on the pump and surrounding areas? Ive already did the injectors and inlet with no huge difference between.

Mick
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Old 02-20-2021, 11:16 AM
ngoma ngoma is offline
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Quote:
Originally Posted by ukvolvo View Post
Would i notice a difference if i did a ear test (long stick in ear to hear vibrations in effect) on the pump and surrounding areas? Ive already did the injectors and inlet with no huge difference between.
Yes, stick, tubing, mechanic's stetheocope, etc. all a useful tools for this instance.

Vacuum pump should theoretically be a clacking sound 1/2 engine RPM (camshaft speed), may intermittently fade in and out.

Injectors have more of a ringing ping, individually repeating at 1/2 engine RPM.
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Old 02-21-2021, 12:26 AM
jpliddy jpliddy is offline
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Default 940 tic auto 1995

i have had good results using a cheap mechanics steterscope, for noise findings on our D24s .its interesting you think the noise might be coming from the pump a which pump injection pump or vacuum pump?
have you tried disconnecting the white 4mm plastic hose at the joint up at the bulkhead near the washer hose Joint . if its the vacuum pump the rattle will stop when this is disconnected , try it a few times ,but dont forget to put it back as
it works the BRAKE master ciylinder . there is a lot of disscusions on the noise vacuum pump ,let us know how you get on .
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Old 02-21-2021, 12:28 AM
jpliddy jpliddy is offline
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Default 940 TIC auto 19955

im based in stoke on trent . what part of UK are you in
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Old 02-21-2021, 03:01 AM
ukvolvo ukvolvo is offline
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Quote:
Originally Posted by jpliddy View Post
im based in stoke on trent . what part of UK are you in

Ill try and run some tests today and im further North buddy, Near Durham

I don't suppose you have a number for the parts place you recommend? The belt is as due as it gets so i should try all sources. I looked all over yesterday to no avail.

I was also told that the vac pump can be tested by applying the brakes and seeing if the noise goes away for a second

Mick
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Old 02-21-2021, 09:01 AM
jpliddy jpliddy is offline
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Default 940 TIC auto 19955

hi yes ive hear thats another method of checking noisy vac pump .but i found pulling the thin white 4mm tube from the T PIECE better for me as its a 1 man operation as your head is under the bonnet at same time .but dont forget to put it back though,
i have been told of a supplier of our cars parts BRICKWERKS .COM based in hudersfeild . they are VW parts stockist .as our engine is a VW they have all the parts last time i checked only down side you have to deal by email and there web site which i find ok . they sell quality parts at the right price you just need to make sure you get the correct year of manufacture PRE 1993 and post 1993 , also another way is to pull off cam belt cover if your car has the high level belt tensioner then its the post 1993 engine so different size cam belt . different water pump etc change the pump while your at it . any more info let us know .
regards jim
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Old 02-21-2021, 12:34 PM
v8volvo v8volvo is offline
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Great suggestions from jpliddy and others on methods for testing/isolating possible noise from the vacuum pump.

One more to add if all other methods fail to leave you 100% certain of the source of the noise (eg stethoscopes, disconnecting vacuum hose, etc): you can also physically remove the vacuum pump from the side of the cylinder head, then remove the pushrod that operates the pump off the camshaft, and then reinstall the pump without the pushrod in place. This will disable the pump and its drive mechanism. It will give you a surefire proof of whether anything involving the vacuum pump is related to your noise.

If you are not accustomed to these engines and other diesels like them, identifying different noises by their subtle unique qualities can be challenging. (eg difference between lifter tap, vac pump noise, injector rattle/knock, loose timing belt flapping and hitting a belt cover, etc). Stethoscope is good but also requires a lot of familiarity with what the different noises sound like. Working on a process of elimination is probably your more certain route if it's all new to you.

If you do remove the vacuum pump at any time, three important things to remember, same as jpliddy said but with a little bit more detail:
1) Before loosening the pump mounting nuts, rotate the engine to near #1 TDC (as indicated by the notch on the injection pump drive gear getting within a few MM of the corresponding notch on the pump bracket) -- this will put the cam lobe that operates the vac pump near its low point and make the removal easier/less risk of damage to the pump housing.
2) Don't let the vac pump push rod fall out when you remove the pump -- watch for it and catch it, as it faces downhill and will want to slide out!! -- and NOTE which direction it is installed, and reinstall it the same way, don't switch it around. Cam side/pump side should stay the same.
3) Don't lose the O-ring gasket for the vac pump, and be careful not to pinch it on reinstallation. If it has a hard time staying in place for reinstallation, use a dab of vaseline or grease to hold it there. If the O-ring is damaged or squashed or lost, it is readily available new. DO NOT use RTV sealer or other goop to replace a missing/damaged/worn o-ring, as this will make the job MUCH HARDER next time you have the pump off and the RTV can also find its way inside the engine to places it should not go.

All that said, the VW/Audi engines with hydraulic tappets like these do sometimes make noise, especially after high miles and/or if oil quality or oil change interval have not always been well looked after. We never saw this in the D24T here in the US as all of ours were the early style with solid tappets. However, related VW/Audi engines are known for it, gas and diesel. So certainly is possible. Fortunately good replacement lifters are available everywhere, same as in the smaller 4cyl engines, and inexpensive. If you trace the noise to a sticky lifter, best bet would be to replace all 12 of them. Only use good OEM quality parts here, like INA, Febi, etc. Soak the new lifters overnight in new clean engine oil before installation to help them fill up, if you need to put new ones in. And of course, if you end up needing to do this, it would be the ideal time to also do your cam belt replacement as the camshaft will need to come out for it.
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  #10  
Old 02-26-2021, 07:20 AM
ukvolvo ukvolvo is offline
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I have actually found some Tappets locally for a fair price. I will do them when doing the belts. Shame i could not do valve stem oil seals same time but hey ho

Mick
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