FW: [A4] Engine swap question

[Tony Hoffman]

On Wed, Sep 3, 2008 at 10:53 AM, Tyson Varosyan <tigran at tigran.com> wrote:
> Hi guys,
>
> I posted the below questions to the A4 list, but looking at their log, that
> list is for some reason kindda dead. Thought that maybe you guys (many of
> whom are gear-heads and A4 owners) can help me out here...
>
> Tyson Varosyan
> Technical Director, Uptime Technical Solutions LLC.
> tyson at up-times.com
> www.up-times.com
> 206-715-TECH (8324)
> UpTime/OnTime/AnyTime
>
>
> -----Original Message-----
> From: a4-bounces at audifans.com [mailto:a4-bounces at audifans.com] On Behalf Of
> Tyson Varosyan
> Sent: Tuesday, September 02, 2008 9:51 PM
> To: A4 Mailing List
> Subject: [A4] Engine swap question
>
> Hi guys,
>
>
>
> I own a wrecked '96 2.8L A4Q automatic - good engine and tranny. I have
> the option to buy a cheap '98 1.8T A4Q 5-speed with a blown motor. The
> idea here is to pull the motor from the wrecked car and put it in the
> other one.
>
>
>
> Questions:
>
>
>
> #1 Will the 2.8L (auto) motor bolt to the stick tranny from the 1.8 car?
>
> #2 What besides the engine will need to be moved? Obviously the ECU, but
> is the engine harness the same? Fuel rail hook-ups? Etc?
>
> #3 Here in Washington State, emission checks for OBD2 cars are done
> without an actual check of emissions - they just plug into the
> diagnostic port on your car, check the ECU for codes and take your $15.
> Problem is, their machine will read that the car has a 4-banger, when in
> fact it will have a 6. Will this interfere with getting future emissions
> tests for the car? Is there a legal workaround?

There are a number of reasons why this won't be a reasonable swap.
Having gone through this myself recently, I can tell you this.......

1: The transmissions in everything since the 5-cyl 90 (that I know of)
have both bellhousing patterns on them, so they will accept the 4,5,6,
and 8 cylinder engines. BTW, the 4-cyl is unique. The others share the
same bellhousing bolt-up.

 2. The 98 V6 A4 used the 30V V-6, so the ECU's are not even close to
interchangable.

3. Another issue, the ECU and wiring harness for your v6 have to be
used in the donor car.

4.Biggest problem, you are trying to go from an automatic to a manual
trans. The crankshafts are different at the back. It's possible to
make it work, but here's what it will take:
a. Pull the sleev out of the A4 engine.
b. Get the pilot bearing that fits the transmission of the new car.
c. Have the sleeve turned down inside to the size of the pilot bearing.
d. press bushing and bearing back into transmission.
e. hope the end of the crankshaft is long enough for stable support of
the bushing/bearing combo.

I went the other way, from a manual engine to an auto trans. The
manual crank is in the are of 1/4-3/8" longer. so, In my case, I had
to grind it down. Also, the bushing hole for the auto is much larger,
so I had the bushing turned down to fit inside the manual pisot
bearing hole.

In the end, I wouldn't try this again unless it was for some sort of
un-duplicatable project. Certainly not for an A4 that you can buy for
$4000 or so. For that matter, you can get 1.8T engines for $2000, why
not go that route?

Tony