Audi A4 ALT Engine Noise

Pretty vague....I would open the hood, have somebody start it up, and try to determine where the sound was coming from...or probably take it to an Audi service center...

Local Audi Service appear not to have a clue

Try a not-so-local Audi service.

I am going to agree with SimpleMind in that it sounds like a collapsed lifter(s).

However, they make a sharp and fairly loud tapping sound. It will sound like something metal is smacking something else metal pretty hard until the oil is pushed back into the lifter and they quiet down. The longer the car sits for a period of time the more likely they will tap upon startup.

I know on the German Porsche 944 engines this was quite common and due to deposits in the engine oil clogging the oil inlet holes of the lifter. Audi may have a similar issue (the two companies are related and often collaborate on projects).

It is important to change your oil regularly and use the manufacture's recommended oil and weight. Don't cheap out on oil and change intervals. Changing the oil may improve the issue over time.

Valve lifters are not too terrible to fix (if that is the problem). You need to find a competent service center to evaluate the car and it will need to be left overnight. Any mechanic worth his salt should be able to identify the problem in seconds after starting.

Yeap, and with nowadays super thin "fuel economy" oils (that also give no sound absorption) this is more of a possibility. Possible also is that not all "lifters" were changed in valve overhaul as OP thinks, since was judged OK optically, after timing belt failure. (All Audi engines I know are Interference engines and everything must be changed at an overhaul)

GA

Can we change that to Good Adea?

I agree its a good place to start and could be an indication of cheap oil or far too few oil/filter replacements or both.

I personally, being a big synthetic oil fan, would replace oil (with synthetic of course) and filter, drive only say 5,000 miles to catch all the crap in the engine, and then replace both only once every 20,000 miles......saving money as well as saving the motor...

Yuck, I can see that one is going to follow me around for life. :)

It was intended to be slightly funny and a compliment to you personally.

I understand and was replying in kind.

Thank you, Andy.

Overworked hydraulic valve tappets tend to leak out their oil when engine stops, and until refilled when engine starts, valve clearance is high enough to crackle badly. (That's the best case scenario). S.M.

I think I agree with you.

Get a good stethoscope or better yet an UltraSound detector and take a listen upon start up. Not only will the sound point you in the direction of the cause but you can read on the scale the DB to locate the actual noise or offending part. These tools are limitless in their value for diagnosing.

You might want to find out if your engine has hydraulic lifters that take some time to come up to pressure.

Thanks folks for all your pretty good comments. I will change the oil and filters first then if the situation remains unchanged, will proceed to having the tappets and or the hydraulic lifters checked. Will keep you all updated. Regards

Hi,

Are you experiencing this? Watch the clip

http://www.youtube.com/watch?v=mBxoPelQC9w

I changed Tensioner and Cam Chain, serviced Oil Pick up Screen and also One Way Valve was inspected and serviced... but no results, issue still presist.

Does it have to do anything with the Starter Motor? heard from someone that bushing in Starter Motor can cause this... however I am not 100% on this.

I only get this noise on Cold Startup. Any help on this will be really appreciated.

Sure this is the noise I experience.same engine and all.any help?

No solution yet.

Can you tell me what else you have done in this regard, till now.

Recently I have changed the oil to heavier weight 10W50 Fully syenthetic because I thought that 5W40 was too much thinner that's why it was draining to the bottom quickly. First few days after putting the heavier oil were better and now again the same thing.

If you could tell me what you have done and we will compare it to what I've done, this way probably we might isolate the problem.

No solution yet Changed the oil(fully synthetic )and all the filters as well as all vacuum hoses two weeks ago. Problem still persists. Two independent mechanics and one from the dealership said problem is unique to the2.0 ALT engines I am at my wits end

I am in touch with another guy who is facing this issue and he will be going to mechanic soon. You can follow or participate in discussion on my youtube link http://www.youtube.com/watch?v=mBxoPelQC9w

To me it looks like bad lifters that are bleeding oil overnight, which they shouldn't. This is my theory however I got response from two other guys who apparently sorted out this issue both have different solution.

1- http://www.youtube.com/watch?v=8qfusQ4_TMU&feature=email&email=comment_reply_received

Check out last comments from Rusbigal that he responded on my query

2- http://www.youtube.com/watch?v=XzBsvsOlUaQ&context=C45fcdb3ADvjVQa1PpcFNHEJFkEWk_QteNVECKUe-EsU85SAGR8sg=

These are the bushings in the starter .... to exchange or relubrication .... Translate the following Inglisz colleagues :)

chiniol20 4 months ago

Now AC Engineer I have given you what ever info I've, can you do me a favor, can you ask your mechanic what could be it based on all the info provided, I don't want to go to my mechanic as I don't beleive them anymore. And if you by chance go for repair can you pl update me the outcome. Thanks

Dear Buddy This coming Sunday am going to remove the drive belt(NOT THE TIMING BELT) and start the engine in the morning.with the belt off, I will check all the pulleys for any bearing noise. Next, I will start the engine. Point is a faulty belt tensioner can cause this noise.i want to be sure whether the noise is external before allowing any mechanic to dismantle the engine. Will keep you posted Cheers

Why not just get an automotive stethoscope?

It's easy to isolate engine noises with that.

Hi to anonymous Hero I can't readily get a stethoscope in my country. Is it possible to get me one? Will gladly pay for it. It's a handy tool which can be useful to me in my auto AC JOB. Thanks

Take a long screwdriver and put the handle to your ear and the pointy end on the engine.

As always, be careful with rotating parts!

If you want to get fancy, get a tin can and attach a log rod to the bottom of the can.

Further to AH's comment with regard to a screwdriver, a length of plastic tube (stiff) connected to a piece of flexible tubing, then a bit of modeller's clay to make it thick enough to stay in your ear.....easy....

Hi AC Engineer... Any update?

I was having a problem with car misfire since last couple of weeks, the problem was Air Breather Pipe was not connected properly. I Got that fixed last week, but strangely after getting this fix, for 2 days the cold startup noise went down to 25% of the original noise. I then thought the issue is almost over, but now it started happening again but now with different intensities, sometime high and sometime low cold startup noise.

This is the update from my side. Does it give any clue?

Hi!

I have too B6 with ALT engine. Same rattle noise 1-2 sec. on cold startup. Rattle noise make adjuster(06B109088D) what is on a intake cam. In europe it costs 400 euro. If you are lucky, then that's it. If not, then back of the engine is a valve(06B103741G or 06B103741F - older version) what needs to replace too (300 euro). Interesting is, when car left overnight nose little bit up (5 degrees), then no rattle or very light rattle in the morning. Excuse my english.

Hope this helps.