m1964

Our 2010 Q5 started making a rattling sound on start up; the sound goes away in 20-30 seconds and sounds like it is coming form outside the drivetrain.
Any ideas?

thanx

Redd

It can be a loose piece of sheet metal, like an exhaust heat guard, that rattles around until it gets hot and expands. Typically to troubleshoot that, a shop would remove all the road pans, put the car on a lift overnight, and then have someone look and listen underneath when started cold in the morning. Unless someone is familiar with the specific model and what parts can make whatever kind of rattle it is...might help if you have someone standing outside to record the noise, so you can share that with folks who might recognize it.

if it sounded like loose silverware in a dishwasher, that would be something else entirely, like engine internals coming apart. FWIW.

John Kean

I have a 2010 Q5 3.2 and I was noticing a rattle for about 2-5 seconds on cold startup and was fearing the timing chain guides were worn but the problem mysteriously disappeared so I am hoping it was something less serious.

S4'ed

Timing chain slap against the lower timing cover?.....have you ever changed the lower tensioner and replaced the chain?
A 2010 would have been built with the old troublesome tensioner, and the least durable chain.
How many miles on this engine?
How often have oil and filter changes been done? Changing the oil every 10,000 miles accelerates chain wear ("stretch").
If the chain or tensioner are the issue, you are risking catastrophic engine failure (repair = $5K to $7K) if you continue driving this car.

John Kean

I have had the car less than 6 months. Carfax shows oil changed every 10k which is not often enough I have recently found. It had 79k when I got it so I changed the old twice since I bought it and has 85k now.

gronk

2010 models only came with the 3.2 V6, so are not affected by the chain/tensioner issue that plagues the 2.0L turbos.

genesysguy

My 2015 SQ5 rattles on most startups.. I was concerned and took it into the dealer and specifically asked about a loose timing chain.. They said it was fine.
Not sure how much digging they actually did, but said that these models had no issues with timing chains.. I hope they are correct.

S4'ed

As is often the case, the people at the Service Dept often don't have a clue.....
There is an Audi TSB for 3.0T rattling timing chains during start-up. The upper tensioner was redesigned to eliminate this problem. Audi claims there is no engine damage due to the rattle. Some people have had Audi replace the tensioner for free, under this TSB. Replacement is a labor intensive (expensive) job.
The TSB # is "15 16 28 2039995/2"
Engines built after 2015 have the improved tensioner.

genesysguy

Ah! Thanks for the info. I wish it was a recall so they would fix it, but perhaps with a TSB and a couple of coughs in their direction will motivate them to fix it.

jimdolian

I have a similar problem with my 2007 Porsche Carrera S. On a cold start-up, I get the rattle for about 15 seconds, then it disappears. No rattle on hot start-up. Finally concluded it is a loose baffle in either the muffler or catalytic converter.