Listen to my engine (noisy on tickover)

mike65

Hi

Me Audi has recently developed a tractor like noise on a warm engine at tickover, its fine on start-up and at revs but warm tickover is a no-no.
I've commited its glory to mp3 which can be downloaded from here it only about 12 seconds long and starts with engine revving then quiet for a moment before the rattle appears. Anyone got any ideas? (don't say tappets please!)

Mike.

Interceptor

Ooh that doesn't sound nice at all... It sounds just like my Civic did when the camshaft came loose. Does it have a timing belt and does it need to be changed? Have you run low on oil recently - is it at the right level now? Is the power noticibly down? I'd bring it to a garage pronto and avoid pulling trailers in the meantime. It is most certainly from the cam/followers but could be anything and may not be serious but might be terminal if you don't sort it.

'cptr

mike65

The timing belt is 60k miles old so yes its near the time, its not down on power at all nor does the noise increase with revs.

The engine is'nt using any oil, but you reckon the top end might suffering oil starvation?

I was going to flush and change the oil this Friday when I have a bit of spare time.

Mike.

crosstownk

For a lot of years now, VAG hydraulic tappets have been a source of noises across all makes & models. Its hard to say from the recording, but I'd be starting by looking at the tappets.

How many miles on the engine? Is it possible that the oil sump gauze may be partially blocked, causing the engine to loose a wee bit of oil pressure as it idles?

I'd start by getting an oil pressure test. If the pressure is borderline low then it could well be the tappets that are not getting oil to keep them pressurised. It's a process of elimination, and the oil pressure test is a good place to start.

mike65

106k on the engine.

Cheers, the car is in the garage Thurs/Fri morning for some bits and bobs and we'll see what 'the man' says. I'll mention a pressure test (the A6 does'nt have a pressure guage annoyingly but it does have an oil temp readout which is of less value in my book).

Mike.

crosstownk

mike65 wrote:

nor does the noise increase with revs.

Do you mean increase in loudness, or do you mean the tapping doesn't increase in speed with the revs?

junkyard

Is it a diesel Mike?:) Seriously I'd say its a camshaft problem tbh.

AMurphy

Does it have hydraulic Tappets or solid shim and bucket?.

If hydraulic, did you change the oil recently?.

if yes to both, did you change the viscosity.

Does if subside with increased RPM or stay with you.

Assuming Hydraulic lifters and any of the above conditions, you may have a gummed up lifter valving, in which case see if you can get Engine oil additive/cleaner and add it to the engine when hot, let idle and take it for a drive maybe 10 min in each case. then change the oil. Or wait until the oil needs changign if your cam can take the hammering for that long.

A/T fluid is a common backstreet Hyd Lifter cleaner on gas engines, not sure if I'd try it on a diesel.... might try it on someone elses diesel though.

Alternatively, check the idle oil pressure and/or change the viscosity.

michaelanthony

The chain tensioner maybe loose.

mike65

The engine is a 20v 1.8 petrol (ADR). I'll know more tomorrow. The oil thats about to be put into it is 10-40 semi-synth rather than 15-40 mineral.

Mike.

crosstownk

The fact that a different oil is used won't cure the problem if your lifter valves are blocked. Some dealers will recommend replacing all 20 valves - Don't fix what isn't broken - just replace the offending lifter/s - assuming lifters are at fault.

@ AMurphy, Audis (and all VAG) have hydraulic lifters - no shims. So if one is at fault it will have to be replaced. No option of a larger shim, unfortunately, for Mike.

crosstownk

michaelanthony wrote:

The chain tensioner maybe loose.

No chain on an ADR 1.8T 20V engine. But it is possible that the belt tensioner roller may be loose - but if it was it would usually be audible as engine speed changes. There would also be a high chance that it would have skipped a tooth by now, and there would be some noticeable power progression difficulty. It is possible that is the tensioner, but unlikely. On a similar note it could be the automatic tensioner for the auxilary drive belt (known for bother on certain VAG models). This tensioner is located near the alternator mounting.

mike65

Sadly its not the turbo version Dunno if the configuration is any different though.

The automatic tensioner is fine as far as I can tell, I replaced the main aux belt last summer and the tensioner did'nt lack for power.

Mike.

crosstownk

ADR is non turbo - sorry. Valve/cam assy is still the same though.

mike65 wrote:

Sadly its not the turbo version Dunno if the configuration is any different though.

The automatic tensioner is fine as far as I can tell, I replaced the main aux belt last summer and the tensioner did'nt lack for power.

Mike.

mloc123

There is a chain on the 20v engines...

The timing belt connects one cam shaft to the crank etc... on the far side of the block the 2 cam shafts are then connected by a chain.

Not sure if this is the correct picture, but it is a similar setup.

http://www.sjmautotechnik.com/trouble_shooting/S4engine/Engine_timing_belt.jpg

crosstownk

mloc123 wrote:

There is a chain on the 20v engines...

The timing belt connects one cam shaft to the crank etc... on the far side of the block the 2 cam shafts are then connected by a chain.

Not sure if this is the correct picture, but it is a similar setup.

http://www.sjmautotechnik.com/trouble_shooting/S4engine/Engine_timing_belt.jpg

Yes - but the chain is usually trouble free and lasts for the life of the vehicle. On some VAG (1,4 petrol and 2.5D) engines a belt is used to drive the second camshaft.

BrianD3

Presumably mike65 has had a careful listen to the engine with the bonnet up, if the noise is related to drive belts/tensioners then it should be loudest in the general area of the drive belts

junkyard

It could be like the Golfs and Bora's......piston slap.

mike65

Updated sound file Another 12 seconds but rather quieter now.

Mike.

crosstownk

Maybe its me, Mike, or the fact that I'm listening to it on a laptop, but the only noise I hear is from the mic (sorry!) being moved/wind noise.

crosstownk

junkyard wrote:

It could be like the Golfs and Bora's......piston slap.

I've a bad dose of piston slap in my 2000 Bora and what I heard in the first clip is nothing like it. I enquired about getting the piston slap sorted (in an engineering shop) and was told that VW main dealers are selling Golfs & Boras c/w piston slap and a letter to say it will not cause any damage! I'm getting all my pistons replaced as the noise just irritates me - it has been for the last 4 years!!!

mike65

If the most you can hear is windnoise (and yep theres some) then its much better! The oil was flushed and renewed and er thats all. Its definitely lost that top end rattle.

Mike.

AMurphy

mike65 wrote:

If the most you can hear is windnoise (and yep theres some) then its much better! The oil was flushed and renewed and er thats all. Its definitely lost that top end rattle.

Mike.

Which might support the idea that one of your hudraulic lifeters is having a problem. You might try some sort of an engine cleaner oil additive. I have used "Marvel Mystery oil" on a VW van with hyd valve lifters and valve clatter to great effect.
if it is making a lot of noise and continues to do it at high RPM, you could wear a flat spot on a cam lobe eventually, this will leave you with a valve noise, even after repairing any hyd lifters.

The chain between cams, usually these things are silent chain with antil backlash gears and never give trouble. So I doubt it is that.

Belt Tensioners; They rumble, squeel, screech, but I have never heard one tip-tip.

IrishRover

Try using diesel engine oil for a thousand miles or thereabouts. I've done it and loads of others have done it. There are more cleaning agents in oil designed for diesel engine oil, but not as abrasive as the engine flushes. Try Castrol GTD in the black bottle.

Crosstownk, what engine is in the Bora and tell me more about the vw piston slap issue please.

mike65

I've heard much about Marvel Mystery Oil from reading US motoring forums and it seems to have a good rep. Can't buy it here though unless someone knows different. The Diesel oil trick I'm familair with.

Mike.

crosstownk

Sounds to me like lifters, mike. I used an Austrailian product on an old 1989 Passat I used to have and worked for a while - IIRC, the product was called 'Roo-Lift'. I did a search and found nada - maybe I mispelt it.

@ IrishRover - The Bora is MY2000 AHW engine (1.4 16V). The piston slap developed in 2002 with 30,000 miles. The car now has 45,000 miles and the slapping is getting marginally louder as time passes - or maybe I'm getting more sensitive to it.

zt-OctaviaN

Ok 60k miles on belt correct?
107k Miles on the engine correct?
Now I aint no mechanic..but why was a belt changed at some stage at only 47k odd miles? are you sure the belt on THAT car requires changeing at 70? or so...?
Maybe first time replacement was by a dealer in which case they need changing at 40k? im only guesssing.
Also look down on top of the belt/wheel system when stationary are any of the belts worn/warped/freyed? also do the wheels look to be rotating very smoothly i.e. not buckled.
n

mike65

Belt first changed at 52k yep it was early but depending on who you belive it should be done anytime from 40k (very cautious peeps) to 80k (offical interval which many belive is way too long).

Mike.