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Need Valve job- 100k 4.2l a6, love it or leave it?

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  #1  
Old 07-27-2007, 11:50 PM
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Default Need Valve job- 100k 4.2l a6, love it or leave it?

Was told today that I need to replace valves to remedy oil burning problem-Quoted $3k by audi master mechanic working through small local shop (he is moonlighting from local audi dealer). I also need a new catalytic converter (1k?) and maybe oxygen sensors. The car has 100k miles, is in otherwise excellent condition (just replaced timing belt, water pump etc.). I'm looking for advice for how to proceed. Audi mechanic recommended doing a trade-in with the dealer, but I'm leary. Assuming that no other engine damage, should I invest the 4k? I love the car, but am only married to my wife.... Thanks.
 
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Old 07-28-2007, 07:53 AM
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Default RE: Need Valve job- 100k 4.2l a6, love it or leave it?

First of all I'd get a second opinion. Do you have the results from a compression/leak down test?

Next, evaluate the rest of the car to get a feel for what's next. If your pretty comfortable that you will have a reliable car, I'd get the work done.

I have never been able to 'get over' on a dealer when trading a car in. It is likely that the trade-in will net you more than $3k less than if you sold the car outright.
 
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Old 07-28-2007, 08:01 AM
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Default RE: Need Valve job- 100k 4.2l a6, love it or leave it?

Wow, tough news. That seems to be one of the bigger-hit service items that comes up with long term 4.2L. What year is the car? I read from one source that it mainly affected '00-01 and that there was a design modification to reduce the wear in later models.

I do believe servicing the heads/valve seals requires pulling the motor- a dicey proposition for one guy in a small shop unless he's been through the drill enough times to be really familiar with all the electrical connections & etc. The advice to have a leakdown test is sound, it will help quantify not only whether the proble is valves/seals, but also how bad it is. You could go some time just dealign with some excess oil burning-- but it sounds like it already toasted your cat so it probably isn't minor if thats the source.

At any rate, for 3K you might be able to get a warranteed used motor with fewer miles. A bit of a dice-roll, but means less wear on some other components (rod and main bearings, rings) if it was properly maintained.

Most folks seem to feel OK about hosing a dealer..but of courseany dealer offering a decent trade valuewill either sell the car or auction it to a used dealer that will sell, so trading defective vehicles probably does mean screwing some 'average joe' somewhere.

I'd say think about how long you'd likely keep the car following a repair and work out what the cost of that 'time' is, compared with a payment on something a bit younger if you trade. It all comes downto your gut though.
 
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Old 07-28-2007, 08:39 AM
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Default RE: Need Valve job- 100k 4.2l a6, love it or leave it?

Also, there is a TSB on the ECU WRT the cats. It may be the catylitic converter is OK.
 
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Old 07-28-2007, 07:53 PM
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Default RE: Need Valve job- 100k 4.2l a6, love it or leave it?

Thanks for getting back to me so quickly. They did the compression test- and ascertained the valve problem. What type of results should I ask for, would be meaningful to get? This is a second opinion, as the dealer already said I needed a new engine about a year ago, and quoted about 10k. Because i had never worked with this one, and have had generally negative experiences, tried to find independent who had Audi background. The mechanic I am now dealing with was apparently certified by Audi.
 
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Old 07-28-2007, 08:11 PM
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Default RE: Need Valve job- 100k 4.2l a6, love it or leave it?

Thanks for the sympathetic and complete feedback. It is indeed a '00. Is the leak down test different from a compression test? I was told that they would indeed need to disassemble the motor to get at the valves. I'm not as much concerned about the skill set involved, as from what I can tell, the same guy has (and continues to work) at the dealer for upwards of a decade.

They seem to be straight shooters as did inform me of the trade in dynamics - yes, even though it is defective, would probably just auction. I don't like the thought of anyone else getting stuck. I bought the car unseen on Ebay (first and only purchse)- and am taking my lumps.

My gut tells me that the car is solid, and as long as the engine isn't otherwise damaged, that it could hold up well for a few more years. My main concern in investing another 4-5k total is how to remove uncertainty that engine will be solid. I was told that the worn valves were due to not changing oil over a long period- and that pistons could also be worn etc. What typically causes the valves to wear? After replacing, wouldn't the engine be - in a sense- refurbished? What other parts might I consider replacing while the car engine is disassembled? Other major wear/tear areas to check? Thanks for sharing your insights!
 
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Old 07-28-2007, 08:19 PM
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Default RE: Need Valve job- 100k 4.2l a6, love it or leave it?

Not sure I got all of the acronyms, but the cat is definitely shot, with pieces of it rattling around. I'm not sure I understood, but apparently there are two CATs, and only one is shot. Mechanic said that he could try to get a non-audi cat and weld it in place to save costs (new audi CAT runs $900?)- mechanic has an older Audi himself, and did this successfully. Because there was some kind of curvature in mine, didn't know if this would work. Thank you.
 
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Old 07-28-2007, 08:39 PM
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Default RE: Need Valve job- 100k 4.2l a6, love it or leave it?

Leak down test: http://www.type2.com/library/engineg/leaktst.htm

How much oil are you using?

 
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Old 07-28-2007, 08:52 PM
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Default RE: Need Valve job- 100k 4.2l a6, love it or leave it?

I am using a quart every 250-300 miles. Thanks for leakdown info.- don't think this was completed. Using 20w 50 oil based on recommendation from previous mechanic. Owner who I bought from was using synthetic. Could part of the problem be from switching oils? Most of what I see recommended on this site is synthetic- but I'm sure this varies based on engine/age and condition engine etc.
 
  #10  
Old 07-28-2007, 09:11 PM
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Default RE: Need Valve job- 100k 4.2l a6, love it or leave it?

For your information (FYI): ECU = Electronic Control Unit (computer), TSB = Technical Service Bulletin (from Audi and typically they will fix at no charge), and WRT = with regard to. Sorry for the shorthand.

Your consumpton is pretty severe, I doubt there is a lubricant or additive fix.

It sounds like you have an honest shop, perhaps they can help you with understanding what may be on the horizon if you go ahead with the repair.

 


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