Can anyone ID this engine noise?

[Simon50s]

In recent months I've noticed more engine noise than before. I can't seem to pinpoint it but it seems to come from the drivers side lower engine section. Perhaps a slight rattle and hard to describe sound/noise when accelerating??



It's a 2006 A3 Sportback with 104,000km/64,000 miles and full Audi service history.

Within the last few years I had both rear wheel bearings done and all brakes checked/adjusted/fixed.

 

[Simon50s]

I've just been listening to some other online videos and I'm thinking it could be the AC compressor / clutch.

Is this a common problem? Will the noise get worse or just stop working?

 

[prt57]

You must take care but you should be able to pinpoint the noise using a long screwdriver.
Taking care that you don’t get entangled in any of the belts, you touch the engine with the metal end of the screwdriver whilst pushing your ear on the end of the handle.
keep moving it until you locate the loudest noise. Just like a stethoscope really.
My bet is the cam chain.

 

[Simon50s]

If it's the cam chain is it something that needs immediate attention?

 

[Simon50s]

I just noticed that when idling with the clutch pressed down there's almost no noise but as soon as I take my foot off the clutch the noise comes. What could this indicate?

 

[norris_309]

Does your car have a Dual Mass Flywheel? If so, it could be that.
I had a mini that sounded similar when idling (but worse) and the noise went when pressing the clutch pedal.

Also listen when turning the engine off, do you get any clatter then? only asking that as i also had a mk4 golf tdi which didn't clatter on idle, but did when turned the engine off, Both cars were suffering from DMF failure.

 

[Simon50s]

I don't know if it as a DMF.

There wasn't any clatter when I turned off the engine.

Today I decided to leave it at an Audi garage rather han risk any further damage even though they might not be able to look at it until next week.

Yes, even the diagnosis will be expensive but I wanted peace of mind. I'll wait to find out what it is and get their quote before deciding if I take it elsewhere for the work. However, I do sometimes wonder whether it's a false economy going to an independant garage if they only use sub-standard non-OEM parts. I've been there.

 

[Simon50s]

Audi main dealer have come back with this:

The sound is located in the gearbox - suspicion of a fault in the main shaft bearing.
No oil leaks.
Checked gear oil quality -> metal shavings in the oil.

They quoted over €5,000 for a new gearbox. I’m waiting for a full quote breakdown.

 

[Simon50s]

The Audi gargage would need to order a new gearbox from Germany and that would be €4,298.

I collected the car today from the garage and will get some more quotes.

Does the fact that there are metal shavings in the gearbox oil confirm it needs replacing?

Is it OK to keep using the car until I can get it repaired? What's the worst that can happen?

I've owned cars with much higher mileage and never had any gearbox problems before.

 

[Simon50s]

I'm sceptical about it needing a new gearbox.

There are videos on Youtube for failing DMF with the same noise. I think my car has DMF but not certain. What's the best way to check?

 

[norris_309]

I'm no mechanic, but metal particles in the oil is a bad sign!
I'd get a second opinion myself as (i might be wrong) but would the gearbox make that noise when idling/stationary?
After listening to the video again, does the noise stay consistent with the revs? (can't quite make it out)
Is the noise a constant tap tap tap and speeds up with revs? or is it a bit random (if that make sense)

Did you ask about the dual mass flywheel? it does sound a bit flywheely to me

 

[norris_309]

go on to eurocarparts & put your reg in & see if they list a dual mass flywheel on there, might give you an idea.
I always thought it was more the diesels that had DMFs but I have a 2005 Petrol Mini Cooper S & that had one too.. so could be petrol cars as well now

 

[Simon50s]

I was a very worried when they mentioned metal particles in the gear box oil but then I also read somewhere it can happen from wear and tear.

I think the noise does increase with more revs.
I mentioned the DMF at the Audi garage but it didn't seem to interest them.

It's booked into another garage on Thursday so I'll let you know what their diagnosis is after that.

 

[Simon50s]

Here's another video for speculation before the second diagnosis tomorrow.

 

[Simon50s]

I found a few other YouTube videos with a very similar sound but unfortunately none of them provided an update on the cause.

 

[Simon50s]

And the verdict is.......

Gearbox failure.

So the Audi garage diagnosis was correct. I was still expecting it to be something else. I suppose the metal shavings in the gearbox oil was the giveaway.

The second garage quoted €2,000 for a second-hand gearbox and new clutch. I'm going ahead with this option as I want to keep it on the road for 1 or 2 more years. Admittedly, at 17 years old, it's one of the oldest cars I've owned, but I've never owned a car which needed a new gearbox. I don't believe it was my driving style which contributed to it's failure, although it could have been from the one previous driver.

I've been checking out some ex demo Audi A3 Sportback hybrids in case I see one which has the spec I want. I'm not ready to jump to plug in or EV yet.

Thanks for your interest and comments!

 

[norris_309]

Yeah after that second video you posted the DMF option was probably out.
At least you have 2 diagnosis that are the same so can be pretty confident that the money you're spending will actually solve the issue.
Shame you have to spend out on something like this, and I guess with second hand cars, you never know how the previous owner(s) drove & looked after cars.

I feel now, with the amount of leased car now a days, the second hand cars that I end up buying won't have been looked after as well as one thats been 'owned' if you know what i mean.

 

[Simon50s]

Yes, exactly. At least I'm now confident that it is the gearbox.

 

[Simon50s]

Just thought I'd provide an update on this.

The first gearbox the garage obtained turned out to be faulty. They had to ship another one from Sweden as there just weren't any available here in Finland. Anyway, it arrived today so I should get it fitted this week.

Small country with small population = shortage of some car parts

 

[Simon50s]

The replacement (used) gearbox was fitted today and cost €2,600 (£2,250).

The noise has gone so it was the faulty gearbox.

I'm still surprised that the gearbox failed with such a low mileage car. I wonder if it had a fault from new.

If I'm faced with another expensive bill I shall part-exchange it immediately. In the meantime I'm going to keep an eye out for an ex-demonstrator A3 35 mild hybrid, ideally in Manhatten Grey, or secondly Floret Silver.