cr8tive

I'm trying to figure out if I should buy a a used engine for my 2007 a6 4.2l or get it rebuilt. I can get the used engine between 3k-4k with under 100k miles. I wonder if its better to just get it rebuilt. I have no idea what it would cost and if this is a better option if the price is close. The engine in my car is close to 200k miles. Please advise. Thanks!

chrisone

rebuilt is better only if you rebuild it with all oem parts and using and using the right audi/vw mechanic but it might cost more than a used one but will be almost new after rebuilding it
a used engine might have it's fair share of problems too unless you get lucky with it

FL C6.5 Avant

I will submit that no modern aluminum block/heads engine is designed to be 'rebuilt'. i'm not saying it *can't* be, but things like the cyl wall finish, bearing tolerances, etc were meant to be factory set and go the distance.
these are not sbc-- don't go ".030 overbore, .010/.010 mains/rods," etc.
I believe the best answer is a rehabbed used motor. this can be tricky and still lead to heartache if you don't know the history of the used engine. But if it has good compression, the forensically examined filter shows no excessive metal, varnish/sludge look ok, then always be proactive and change out the known wear-out items including chains and tensioners, re-seal/gasket everything.
and don't be fooled by some 12/12k 'warranty' on the used motor-- very unlikely said warranty will cover leaks. one must do their due diligence with the rehab prior to install.

newa6er

Does you motor still work?

cr8tive

Thanks for the insight everyone.
As for the current motor, the oil is milky. Its been sitting a while. When the engine starts, white smoke comes up from the exhaust. The mechanic said the head gasket is blown, chain and tensioners are off and something about the transmission. Like I said, it was a daily driver and I thought I got a good deal. The mechanic pulled some code but once I get the paper work in front of me I'll come back and post it.

localbrew

Just be very careful about the used engine scenario; some will warranty the engines but they don't warranty the labor of getting your indy to pull it and put another one in. I made this mistake on a range rover; in hindsight I should have had them rebuild only what mine needed, instead I opted for the used engine. They got it in all worked well it drove fine but had a slight knocking noise in the lower end. Worst decision I made was the used engine, they were going to warranty it but I wasn't going to pay the labor again. Sold the car to a dealer about a week later. Funny thing was the car has been fine ever since (the dealer sold it to a client he knows).

I'd go the rebuild route if you want to keep the car, new gaskets, tensioners, etc. can't set you back that much. Won't be cheap but at least you know what you are dealing with (existing engine) vs. getting an unknown used problem.

Good luck though, let us know how turns out.

Fastbird

I'll agree with part of this, but you can actually rebuild the sleeved aluminum block motors so long as there's no major sleeve damage, typically with a .005 hone and slightly oversized pistons. LSx stuff is the same setup, aluminum block with sleeves, and countless of those have been rebuilt just with putting new pistons and a hone on the cylinder to clean it up. Should be the same for any sleeved aluminum motor unless they're using unobtanium for the sleeves, lol.

KevinGary

We are starting to see more and more C6 cars being sold at auction with bad engines. Have you thought about simply parting out the car?