1990 A90 Quattro VERY Noisey tappets.

**Mr Tickle** · 15-08-2007,09:22 PM

Hi All,
I just bought myself an Audi 90 Quattro (10 valve) yesterday which has developped very noisey tappets while warming up. At times it's like someone has a small hammer banging on the rocker cover and very embarracing while driving down the street.
Once warmed up it quietens down and you can barely notice it. At tickover hot or cold the engine is quiet.

Is it just the hydraulic tappets? I've had a look on German Swedish & French but cannot seem to find new ones for my car. How big a job is it to replace them and will I also need a new cam?

Thanks in advance

Mike

**stuart** · 15-08-2007,09:29 PM

The Hydraulic lifters were a common problem on early VAG cars. You could try running some engine flushing oil through the engine, then fill with a good quailty engine oil. This may stop the noise if they are "sticking"

I do know that GSF or Euro Car Parts do good quality replacements if needed. I would find it highly unlikely you will need a cam

Just found this on the GSF site, under cylinder head

14537 CAM FOLLOWER-HYDRAULIC A90 2.2 10/84 > 6.50 Add
14537 CAM FOLLOWER-HYDRAULIC A90 2.0 8/85 > 6.50 Add

**scotty33** · 15-08-2007,11:40 PM

There is another possible cause, the 10v has a vacuum pump for the brake servo, this can get noisy and apparently sounds a lot like tappets. It's bolted to the left side of the block, and it is possible to remove the pushrod inside, which stops the pump working and stops the noise. It would be worth trying this before attempting tappets...
I heard that the pump is only there to boost vacuum, for those times when the driver is on the gas and brakes at the same time, so if you are not a left foot braking fiend, you probably would not notice that it is not working

I think the rod can be bought seperately if you need one.

**Millerman** · 16-08-2007,06:09 AM

Cant comment on the 20v, we have a A80 2.0 and i've just removed the cam shaft and lifted the buckets (hydraulic lifters) out and soaked them in petrol for a few hours, its amazing the amount of crap that has come out of them, should be nice and quite when reassembled.

**Mr Tickle** · 16-08-2007,09:03 AM

Thanks for the info guys. I really appreciate the advice given and I'll certainly try doing that before anything else.

Thank you very much

**Mr Tickle** · 16-08-2007,05:26 PM

Thanks a million guys

I put some engine flush in with the old oil and I also took out that pushrod. After draining the oil and renewing the oil filter & fresh oil the knocking has now gone.

**stuart** · 16-08-2007,07:42 PM

Glad you are sorted

nice the hear the forum has helped

**m4xmw** · 21-08-2007,02:02 PM

My 1990 902.3 10 valve liked new oil every 3-4k, the tappets were noticably noiser on start with older oil.

My advice is to change the oil( 10w40 bog standard) and filter every 3k miles.
Gsf sell the filters fro 2.00+vat and oil is cheap enough.

It should keep your engine happy for years like that!

Mark

**Mr Tickle** · 21-08-2007,03:01 PM

Under load it's still rattly even tho I've put in new oil & filter plus some additive to loosen the hydraulic tappets.

The Haynes manual suggests 20/50 oil so that's what went in. Is that thicker or thinner than 10/40?

**m4xmw** · 21-08-2007,05:02 PM

My audi 90 used both 15w40 and 10w40.

this is a quite a lot thinner thean 20w40.

It had 154k on it when I sold it and it was liking 10w40 that was used then.

Engine seemed very smooth and quiet, and didnt use any oil.

I`d try again with 10w40 and a new filter..

See how that goes.

Mark