Bhf bottom end rebuild

[Dcass08]

Does anyone know of a DIY or maybe a manual available for rebuilding the bottom end on a 4.2 BHF motor? I've been looking around but haven't had any luck. Any help is much appreciated. Thanks

[Jake@JHM]

Does anyone know of a DIY or maybe a manual available for rebuilding the bottom end on a 4.2 BHF motor? I've been looking around but haven't had any luck. Any help is much appreciated. Thanks

What are you looking to do exactly?

[Dcass08]

Nothing crazy, just looking to fix the minor scoring and re-ring it. It's using oil and I get smoke on startup sometimes. I plan on reworking the heads as well.

[dparm]

Per the previous discussions on Alusil manufacturing processes, it's very difficult to do bottom-end rebuilds.

[A.LACK]

Not much you can do with the scoring due to the coating on the aluminum cylinder walls. I wonder if a re-sleeving is an option on these motors.

[FulhamFTW]

Not much you can do with the scoring due to the coating on the aluminum cylinder walls. I wonder if a re-sleeving is an option on these motors.

SEE: JHM

[viridia]

If you're a shadetree mechanic there are some things you can try. Because motors with scoring burn oil, the piston tops, piston ring grooves, and valves become caked with carbon deposits. I did a maintenance teardown and cleaning on my motor which helped significantly since the piston rings were seized with residue.

There's no simple cure for scoring, but cleaning can definitely improve your engine's health and power (for a time...)

Then again, I'm more brash than other forum members...and have another engine if I ever mess-up.

[A.LACK]

SEE: JHM

I can only imagine the cost.

[jeffrey146]

Unless you're trying to get a lot of power out of the motor a used motor makes more sense to me at least.

[Slow4]

Because motors with scoring burn oil, the piston tops, piston ring grooves, and valves become caked with carbon deposits.

yup! I have pictures of this from my breakdown...

[viridia]

yup! I have pictures of this from my breakdown...

Mine were much worse

[jeffrey146]

sort of related question: on these motors can you pull the crank, rods, pistons out through the bottom or do you have to pull the motor to do this.

[Slow4]

Yikes, ya mine didn't look as bad. My #6 had scoring that was more noticeable than other cylinders.

[viridia]

sort of related question: on these motors can you pull the crank, rods, pistons out through the bottom or do you have to pull the motor to do this.

Only scenario I can think of is if you also removed the subframe and the heads. Then, the bottom two oil pans would come off and the pistons would come out the top after the conrod was disconnected from the crank. That all sounds rather painful though. Even removing the top timing covers with the engine in the car is super annoying.

[discoverdeath]

this would be rather silly... how would assemble it????

[jeffrey146]

I just know people do it on the 1.8t. I think it would be more logical to pull the motor out of the car. I was just curious though.

[Dcass08]

Mine were much worse

Yeah, mine are not that bad.

[Das Audi]

Does anyone know of a DIY or maybe a manual available for rebuilding the bottom end on a 4.2 BHF motor? I've been looking around but haven't had any luck. Any help is much appreciated. Thanks

It might be worth e-mailing this guy to get a price on a low mileage engine

http://forums.vwvortex.com/showthrea...6spd-24K-miles

[Brandywine050]

I have similar scoring thats quite shallow that you cannot feel. there are few people that can hone or "re-expose" the plating using an exposure paste and felt honing pads that to my knowledge only sunnen makes. and you won't know the magnitude of the damage without having it inspecting and honed.