Audi S4 B6 4.2L V8 swap into B6 A4 1.8T

**trent_teezy** · 05-23-2016 12:28 PM

I was wondering if there are any DIY threads on anyone completing the swap from the Audi S4 4.2L engine into the A4 B6 1.8t? Can anyone give a Simple break down on what's needed to do the swap?

I've found really good deals on used low mileage Audi S4 B6 engines and this is why I considered the swap in the first place.

Also because of the fact finding a B6 S4 in my area are pretty rare to find and expensive cheapest S4 I seen was a 2005 with 168k miles for 6500$ on Craigslist. And some 7000$ and up at the dealerships low mileage and in good condition.

And if this swap Is too expensive I might just go for a B6 S4 from a salvage auction like copart and other salvage sites or just save up for a clean title one.

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**PreciseD** · 05-23-2016 12:32 PM

I have a feeling that it would be cheaper to buy the one on craigslist when it's all said and done.

**AudiA4_20T** · 05-23-2016 01:33 PM

If you have a source for cheap 4.2s you should make side money selling them to the B6 S4 guys

**Furly** · 05-23-2016 01:44 PM

Who in their right mind would want to swap the biggest piece of crap engine audi ever made into an a4?

You are better off buying a B6 S4 and getting a POS that has recaro's and other upgrades.

Seriously though. If you want to swap a 4.2 use one from a C5 or D2.
Not trying to sound harsh but the B6 and B7 S4 are trash.

Not to mention you'd be sad when a modded 1.8T pulls on you and leaves you bus lengths behind him.

**moyenecorniche** · 05-23-2016 01:50 PM

I have to say OP your question doesn't make much sense. Installing the 4.2 into an A4.. You still will have to ...
(1) Upgrade brakes to at least the S4 if not BBK
(2) switch from that A4 interior to the S4's Recaro.
(3) Harness changes and ECU remap..
(4) Trans, switch to a 6 spd.
(5) Suspension upgrade ( heavier motor ) needing S4 dampers and springs. Sway Bars and more...
(6) Complete exhaust change to twin banks ( not cheap )
(7) Why ????

By the time you are done you'll probably have spent close to $15,000 and you still have an A4 unless you convert everything, which doesn't make sense.
You can find a very nice S4 for around $12,000 to $17,000 and have it shipped for less than $1,000 from anywhere in the continental US.
The only real conversion that makes sense is taking a B7 S4 Avant and fully converting it to an RS4 Avant....

**Furly** · 05-23-2016 02:05 PM

Originally Posted by moyenecorniche

I have to say OP your question doesn't make much sense. Installing the 4.2 into an A4.. You still will have to ...
(1) Upgrade brakes to at least the S4 if not BBK
(2) switch from that A4 interior to the S4's Recaro.
(3) Harness changes and ECU remap..
(4) Trans, switch to a 6 spd.
(5) Suspension upgrade ( heavier motor ) needing S4 dampers and springs. Sway Bars and more...
(6) Complete exhaust change to twin banks ( not cheap )
(7) Why ????

By the time you are done you'll probably have spent close to $15,000 and you still have an A4 unless you convert everything, which doesn't make sense.
You can find a very nice S4 for around $12,000 to $17,000 and have it shipped for less than $1,000 from anywhere in the continental US.
The only real conversion that makes sense is taking a B7 S4 Avant and fully converting it to an RS4 Avant....

Most B6 S4 in my area are selling for less than A4's.

$5k to $8k seems to be the average going rate right now. Nobody wants them. They sit on Craigslist forever.

**imnuts** · 05-23-2016 02:19 PM

Off the top of my head, you're basically going to need to buy an S4 to get the parts you need to do the swap on a 1.8T. ECU, harness, engine, exhaust, intake piping, cooling system, and probably much more. You're going to end up spending more than the $6500 that the used S4's are selling for IMO.

**mauromj** · 05-23-2016 02:37 PM

Why not do this? :)

Much better option...

**hightime80** · 05-23-2016 02:43 PM

At least the op isnt trying to pass a fake europlate for a real one, lol.

**Furly** · 05-23-2016 02:57 PM

Originally Posted by mauromj

Why not do this? :)

Much better option...

This, I like.

**moyenecorniche** · 05-23-2016 06:05 PM

I think you just blew up the OP's budget with that last one.

**eljay** · 05-23-2016 06:52 PM

Originally Posted by mauromj

Why not do this? :)

Much better option...

I'm a newb, so school me please... Is that a 3.2L VR6 or FSI?

**texasboy21** · 05-23-2016 07:01 PM

Originally Posted by eljay

I'm a newb, so school me please... Is that a 3.2L VR6 or FSI?

2.7T with a single turbo (STK - single turbo kit).

**eljay** · 05-23-2016 07:06 PM

Ah, cool. Learned something. Thanks.

**egovreau** · 05-23-2016 08:25 PM

Even the 2.7T bi-turbo would be a better option. And there's a pretty detailed DIY for the swap.

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**moyenecorniche** · 05-23-2016 08:57 PM

Still either consider buying a B5 S4 or a B6 S4... I don't see where the value is in the amount of expense and work bringing an A4 to the next higher level....
Let's put it this way, were you to implant a 2.7TT into the A4, That would just be the beginning. A B6 A4 with the specs of a stage III 2.7TT S4 would be a very different animal but not inexpensive to accomplish ...

**trent_teezy** · 05-24-2016 03:38 PM

You guys are FUNNY some more funny than others. BUT I'm here to thank you all for your expert advice and decison suggestions.

I had no idea that I would I have to Interchange so much stuff in the A4 to be eligible for the 4.2l S4 engine to work and fit properly.

So, with that being said I'll just go ahead and search around lots and classifieds like CL and etc for an low reasonable price B6 S4.

Also if I find one not in my area I'll just pay minimum of 1k to have it shipped to me here in DTX. (Dallas Texas) for the 4.0 GPA Harvard graduates that don't know the slang term.

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**trent_teezy** · 05-24-2016 03:58 PM

Originally Posted by PreciseD

I have a feeling that it would be cheaper to buy the one on craigslist when it's all said and done.

yeah that's why I have my mind changed on what I'm going to do.

Originally Posted by AudiA4_20T

If you have a source for cheap 4.2s you should make side money selling them to the B6 S4 guys

yeah pretty much I can get them for as low as 1k to 3k depending on condition and miles.

Originally Posted by Furly

Most B6 S4 in my area are selling for less than A4's.

$5k to $8k seems to be the average going rate right now. Nobody wants them. They sit on Craigslist forever.

Yeah that's the Main reason why I'll just wait and find one and if neseccary have it shipped to me.

Originally Posted by Furly

Who in their right mind would want to swap the biggest piece of crap engine audi ever made into an a4?

I Certainly would if I had the everlasting money to blow on upgrading my car like these little spoiled rich kids who got their first car spoon fed to them by their parents who make sure that their child doesn't have to "work too hard". But no obviously that's not me. Nor am I willing to waste money down the drain.

Originally Posted by moyenecorniche

I think you just blew up the OP's budget with that last one.

Probably so my budget was around 10k for this swap. And I'll leave the single turbo or twin turboing for my 08 HR 350Z when I start putting money into it. If you guys are on any of those 350Z or Z forums you'll see me post in there quite a bit when that time comes.

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**moyenecorniche** · 05-24-2016 04:54 PM

So we're Funny Eh !! ???

Plano is that like level ground or more like Piano .. Piano as in the inverse of Fortissimo ... ;-)

On the subject of B6 S4's .... Careful in thinking you are going to get one for around $7,000 ... NO .. not one that has been well lvdd and is up to spec after 85,000+ miles.
The 4.2 is a reliable motor but it is high maintenance. There are different versions of it. The 2003-2005 B6 S4 and the allroad shared the 4.2 V8, but unfortunately the other option of motor for the allroad was no longer available for the S4 ( 2.7TT ).
I may be wrong but I would suspect that the harnesses and all the needed hardware for the 2.7TT motor that was fitted in the 03 allroad would also be compatible into the B6 S4. They are both basically the same A4 platform.
Anyway on the 4.2 S4 have patience sand look for a really nice one. low mileage if possible but definitely one with all service / maintenance documentation from day one and one that when you inspect it it looks like it is still lightly preowned... So that will cost you in the short term but buying an S4 to save $$6,000 will bite you around the next set of curves...
There are a few A-ziners here that sell their S4's every so often. Best to wait for one of them and get one that has been in the family....

**g huns** · 05-25-2016 07:45 AM

I always laugh at the B6 S4s I see on Craigslist. Low miles, immaculate condition, etc. Always seem to have just under 100K on them. Seem to be between $6500-8500.

Wonder how many people buy them without doing a google search to see what awaits them?

**trent_teezy** · 05-25-2016 03:19 PM

Originally Posted by moyenecorniche

So we're Funny Eh !! ???

Plano is that like level ground or more like Piano .. Piano as in the inverse of Fortissimo ... ;-)

Yes you guys are FUNNY! I had a good laugh reading most of the replies lol.
But it's actually pronounced "plain-oh" or "play-no" or however you want to pronounce it. It's whatever floats your boat.

Originally Posted by moyenecorniche

Anyway on the 4.2 S4 have patience sand look for a really nice one. low mileage if possible but definitely one with all service / maintenance documentation from day one

Yeah I'm going to take your word on that since you know what you're talking about and have the knowledge to back it up and just search for one in the best condition that I can find and see if they have all the maintenance records and etc.

Originally Posted by g huns

Wonder how many people buy them without doing a google search to see what awaits them?

Lol I feel like this was aimed directly towards me LOL. I've been searching on online lots and CL for one that has been preferably babied and not beat on. I'll post the links to the good ones I find for you Audi Exeperts to evaluate and give your suggestions and judgements.

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**g huns** · 05-26-2016 11:52 AM

Originally Posted by trent_teezy

Lol I feel like this was aimed directly towards me LOL. I've been searching on online lots and CL for one that has been preferably babied and not beat on. I'll post the links to the good ones I find for you Audi Exeperts to evaluate and give your suggestions and judgements.

Nah. Just in general.

People can baby them all they want. But you can bet the people selling them cheap, with just under 100K miles, know what the cost of fixing that little rattling noise they just started hearing is.

**moyenecorniche** · 05-27-2016 10:31 AM

Originally Posted by g huns

I always laugh at the B6 S4s I see on Craigslist. Low miles, immaculate condition, etc. Always seem to have just under 100K on them. Seem to be between $6500-8500.

Wonder how many people buy them without doing a google search to see what awaits them?

You'd be surprised .... There are often rant posts on FB from people who've bought an S4 B5 or B6 ( both have their costs ) thinking RACE KAR ...

without ever doing some homework and really finding out that these are high maintenance and don't respond well to neglect..

To OP, S4's in great shape from day one are out there, but you have to also research elsewhere than the common classifieds. I just bought an 05 Allroad and that was totally thru a friend connection and it had not been advertised or listed yet. I was just lucky to be in the right time slot...

What you seek may not be exactly what you had in mind ( I wanted an Avant ) but sometimes what you find is better than your expectations..