B6 S4 4.2L Alternatives

[Dagear]

All,

I have the option of purchasing a 2005 125 K miles, S4 for $1500

Problems
-1 piston has major damage, spark plug disintegrated and pieces poked holes in piston top.
-1 piston has 2mm x 2mm knick.
- Other 6 carbon buildup and black marks on cylinder walls
-all seem to have vertical lines 180 degree opposed, not sure what these are.

Assumptions
1. Current motor is trashed, so would need to rebuild existing or purchase used

Questions.
1. I am not after HP, just return to stock. Any cost estimates for getting it back to stock if I do the labor myself except for machine work.
2. Are there options for a different engine? V6 with less HP?
3. Anyone have a similar story

[S4NIK8]

buy a good used engine and swap it in; easiest route to go.

Wolf auto parts in Minnesota usually has some in stock but do the chain service before installing.

[scottkollig]

Go 2.7 bi turbo. Lots of gains to be had there.

[Dagear]

Go 2.7 bi turbo. Lots of gains to be had there.

Is the 2.7 a direct swap or are mechanical electrical mods necessary?

[scottkollig]

http://www.audizine.com/forum/showth...DIY-Swap-Guide

[Davednconfused]

Not really sure why you'd want to put in a different motor such as a regular old v6. In that case - why not just buy an A4?

Concur with above statements though. Just get a used 4.2.

[noob5]

Not really sure why you'd want to put in a different motor such as a regular old v6. In that case - why not just buy an A4?

Concur with above statements though. Just get a used 4.2.

2.7T is a twin turbo V6 capable of huge gains and endless smiles when they're properly tuned/built. Also, just fyi, it was never offered in the A4.
But I do concur with the statement that a direct 4.2 swap with timing service would be easiest.

edit: Davednconfused, I misread this thread, I thought you were wondering about the 2.7t swap, rather than OP asking about plain-jane V6 swap, which for the record, I don't understand either. Kinda' like putting a sheep in wolf's clothing.

[Davednconfused]

2.7T is a twin turbo V6 capable of huge gains and endless smiles when they're properly tuned/built. Also, just fyi, it was never offered in the A4.
But I do concur with the statement that a direct 4.2 swap with timing service would be easiest.

I know what the 2.7T out of the B5 is capable of. However, it seems like he is looking for something less high strung to daily. I'm just curious as to why he'd pick an S4 over an A4, since realistically one can make an A4 look like an S4 pretty easy.

[noob5]

I know what the 2.7T out of the B5 is capable of. However, it seems like he is looking for something less high strung to daily. I'm just curious as to why he'd pick an S4 over an A4, since realistically one can make an A4 look like an S4 pretty easy.

Haha...yeah, my bad, I got dazed and confused earlier. I had to edit my post.

[Davednconfused]

Haha...yeah, my bad, I got dazed and confused earlier. I had to edit my post.

No problem haha, done it plenty of times myself.

[Dagear]

A4 over S4?? Main reason is purchase price of 1500.00. Nice convertible just looking to get it on the road as cheap as possible.

[S4NIK8]

A4 over S4?? Main reason is purchase price of 1500.00. Nice convertible just looking to get it on the road as cheap as possible.

I would be prepared to spend 5-6,000 for an engine/timing service and misc expenses in addition to the purchase of the car assuming you do all the work yourself.

[sandspeed]

Buy my 4.2 engine after I fix the oil leak?

[Dagear]

Found a complete 2006 A6 with 4.2 AWN Engine 145K miles. Any concerns with number of miles?

I have a build thread, but not getting any response / comments.

[gautam]

LS SWAP!!

[Dagear]

Sorry what does LS mean

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[Videris]

Sorry what does LS mean

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LS1 or other LSX motor. It's a Chevy motor

[neilpaku]

Mic the bores on your current engine to see if the block is salvageable, including those black marks (180 degrees apart suggests wrist pin - are the marks all oriented the same, fore-and-aft on the block?). You might "only" need hone, pistons, rings, and the timing chain service. Or pickup up a decent runner in a wreck and just swap it over. That's probably your easiest option on this 1500 car. You might only need to pay 2k for a replacement used engine. If you want to do the timing chain components, it all depends on what needs replacing. The two broken guides are ~$70 each, plus you'll need a bunch of replacement hardware for the torque to yield bolts (maybe a couple of hundred for all of them including subframe, axle bolts, etc. If you want to replace the camshaft sprockets with JHM ones, those are 750 a pair.) On the current block, if you only replaced the damaged pistons (100-200ea), you'd definitely want to replace all piston rings (800) even on the remaining pistons and a full hone (<100 - buy the paste and a three arm hone from Harbor Freight).
I'd go with the replacement used 4.2 with the timing guides replaced as the least cost/labor-intensive/reasonable longevity option.

[Dagear]

Mic the bores on your current engine to see if the block is salvageable, including those black marks (180 degrees apart suggests wrist pin - are the marks all oriented the same, fore-and-aft on the block?). You might "only" need hone, pistons, rings, and the timing chain service. Or pickup up a decent runner in a wreck and just swap it over. That's probably your easiest option on this 1500 car. You might only need to pay 2k for a replacement used engine. If you want to do the timing chain components, it all depends on what needs replacing. The two broken guides are ~$70 each, plus you'll need a bunch of replacement hardware for the torque to yield bolts (maybe a couple of hundred for all of them including subframe, axle bolts, etc. If you want to replace the camshaft sprockets with JHM ones, those are 750 a pair.) On the current block, if you only replaced the damaged pistons (100-200ea), you'd definitely want to replace all piston rings (800) even on the remaining pistons and a full hone (<100 - buy the paste and a three arm hone from Harbor Freight).
I'd go with the replacement used 4.2 with the timing guides replaced as the least cost/labor-intensive/reasonable longevity option.

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[S4NIK8]

Found a complete 2006 A6 with 4.2 AWN Engine 145K miles. Any concerns with number of miles?

I have a build thread, but not getting any response / comments.

The A6 is an FSI engine isn't it?

[neilpaku]

I see what you're saying : ) - that damage wouldn't stop me from mic'ing it to find out, but in any case, it would be cheaper in the long run to buy a good used engine than fixing that one.

[q_dubz]

Yep, mic it. Then get sunnen paste hone it. Drop in some forged internals and new rings.

Turbo it.

Love life! 😁

[Dagear]

Teetering between good used engine and a 4.2l 077 engine series swap

I don't have any experience with engine rebuilding


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[sandspeed]

If it's a hobby car and can be down for a while, you could also look into a 3.0T swap.

[Dagear]

Ordered used engine today 105K miles. Comes out of an 07 S4 but still plan to do timing components.

[neilpaku]

Ordered used engine today 105K miles. Comes out of an 07 S4 but still plan to do timing components.

Excellent - that's how I would have done it. For another measly 800 : ) you can get new valve guides and seals installed and see your oil consumption drop to zero (ok exaggerating but ...) Pre-cat gutting will cost a $16 auger bit from Home Depot. Buy a pot of antiseize and spread it on everything : )

[Dagear]

Since you mentioned those 2 items.

1. My Exhaust is Milltek, where are the pre-cats, catback etc. What benefits to gutting cats?
2. Do the heads have to come off for valve guides? Un easy of tearing the engine that far down.

[Dagear]

Does this look acceptable for mounting a bhf 4.2 to an engine stand concerned about the nut by my finger there the torque breaking the casting

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[Dagear]

Does this look acceptable for mounting a bhf 4.2 to an engine stand concerned about the nut by my finger there the torque breaking the casting

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[Dagear]

Both engines mounted on stands yesterday.

Question is it feasible to do a compression check on an engine mounted to stand? Fill up with oil and run starter? or would leak down test produce same results.

Also for Moderators, is is possible to move a thread from one forum to the other? I have a build thread under projects, but seem to get more response when post in the main section, and I have feeling that I will need some help as I progress through this engine.

[q_dubz]

Sweet I'm gonna mount mine like that

[Dagear]

Sweet I'm gonna mount mine like that

Qdubz. 2 posts back i actually asked if this was the proper way to mount a bhf motor




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[q_dubz]

Qdubz. 2 posts back i actually asked if this was the proper way to mount a bhf motor




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I know. I don't have an answer for you as to right or wrong... However you followed with you had both engines in stands.

My mind says so long as you don't leave it fully dressed on stands for a long time then you're fine.

[Dagear]

I know. I don't have an answer for you as to right or wrong... However you followed with you had both engines in stands.

My mind says so long as you don't leave it fully dressed on stands for a long time then you're fine.

I placed a support at flywheel end to relieve the stress from mouting bolts

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