I bought a used 2004 Audi 3.0 Quattro this past weekend that has been kept in immaculate condition...112000 miles. The person had all the service and maintenance records so I felt confident about the purchase. Upon reviewing what was fixed, he had a $2900 repair two months ago, not sure what would cause this and if it's something to be concerned about. The invoice says:

LABOR: Check rough running - check engine light - scan system - missfire #2 cylinder - #2 cylinder no compression - remove bank 1 cylinder head and inspect - #2 cylinder intake valve not seating properly due to some broken pieces from intake adjusting unit - reassemble bank 1 cylinder head and replace intake adjusting unit with parts as listed.

PARTS: Intake adjusting unit; Cylinder head gasket; Cylinder head bolt; Thermostat assembly; Water pipe o-ring; valve cover gasket; Intake manifold gasket; Upper radiator hose; Spark plugs

What would cause cylinder #2 to misfire and what are these broken pieces about? Is this a common problem? Should I be concerned about the same thing happening to the other 5 cylinders?

I noticed he was using synthetic oil 5W-30 up until about 97k miles at which time he used 15W-40 oil (Live in southern california), then he switched back to synthetic at 100k miles, then switched back to the 15W-40 oil. This engine repair happened at 110k miles. DO you think it had anything to do with this switching back and forth of oils, or what woudl the cause be? Thanks.

 

Anyone know?

 

I'd think it would be very tough to get the back story from just the invoice, but have you thought about giving the shop a call and taking to the tech? I'd think they would remember whatever horrors caused all the replaced parts, and most techs don't mind telling a story.

When I was about to buy my A4 I called the closest Audi dealership and gave them the VIN, they told me the entire service history of the car (that they've seen) with no hassle or charge. If you play it that you saw this large invoice and wanted the back story in case there were any other related repairs they should do, they should be more than willing to spill the beans on it.

Give it a go and make sure to share the story with us too!

 

I don't think the oil is really an issue.


sounds like the "intake adjusting unit" broke and the pieces from it got sucked into "Cylinder #2".

foreign material in the topside of the cylinder would cause the misfires and the damage would lead to the failed compression test. sounds like the shop got everything taken care of.

FWIW I have no idea what an "intake adjusting unit" is supposed to be.

I agree with tthrock, call the shop that did the work and ask questions.

good luck

 

Thanks for your guys' input. I'm actually going to go to the shop and ask them today. Sounds weird that some plastic thing would break and pieces go in the cylinder. Anyway, I'll let you know what I find out....thanks again!

 

So I went to the mechanic and asked what the repair was about, he said the intake runner broke and the plastic pieces went into cylinder 2 causing it to misfire and lose compression. He said the plastic got brittle due to it being old and worn out.

He said it shouldn't happen again and it's good now.

i've never heard of that kind of thing before, Is that a common problem? 7 years doesn't seem that old for plastic to be worn to the point that it's brittle...

 

I've never heard of the internal pieces of an intake runner breaking before, but its common knowledge that the plastic arms that actuates the flaps do. I hate the 3.0L, when the cat converters go bad expect to pay $1,000 PER cat plus 4 hours of labor to install them, timing belt replacements can exceed 3k (shop depending) and there is the mysterious coolant leaking into the cylinder phenomenon for which there is no fix as im aware. I would get rid of it.

 

Oh, sounds like you had a bad experience with the 3.0L? How many cat converters are there? The previous owner already changed the timing belt at 91k miles. So you think it was a bad purchase and this car is loaded with reliability problems and things breaking down?

 

^^^^^

as a (former?) Audi technician, he has worked on these things for a living. The 3.0 engine is a real PITA to work on, one of the most hated by the technicians. Also, being from Cali, they can't get away with the cheapie cats due to the emissions restrictions.

I think from what the mechanic told you, it was the plastic arm that actuates the flaps that broke as Auditech79 mentioned. Sounds like the repairs were done correctly. Don't be too afraid of your car, just be aware that when something does go wrong, it goes wrong expensively.

 

the same can be said of any luxury brand.