Can I swap b8.5 in my b8 s4?

[Memehotep]

So I bought a 2010 s4 with a siezed engine. As I've been looking into things I found the 2012 and up s4's made design changes in the later 3.0 tfsi engines. I've found some good prices on junkyard engines from 2015 Q5's and the engines look identical from what I can tell. I've read the superchargers are different and the exhaust manifolds are different, but is there anything else im missing? I'm concerned they may have extra sensors or possibly different cams which would cause check engine light or performance issues. Any input on the matter is helpful.

[Shane Horning]

So I bought a 2010 s4 with a siezed engine. As I've been looking into things I found the 2012 and up s4's made design changes in the later 3.0 tfsi engines. I've found some good prices on junkyard engines from 2015 Q5's and the engines look identical from what I can tell. I've read the superchargers are different and the exhaust manifolds are different, but is there anything else im missing? I'm concerned they may have extra sensors or possibly different cams which would cause check engine light or performance issues. Any input on the matter is helpful.

There are small differences here and there but you will be able to make it work no problem.

[Memehotep]

Ok, so nothing i couldn't just transfer over from my old engine?

[Shane Horning]

Ok, so nothing i couldn't just transfer over from my old engine?

Correct

[Smac770]

CCBA from MY10-MY12 S4 sedan or S5 cabriolet would be the most direct drop in.
CGXC from MY13 or CTUB from MY14-MY16 would need tweaking, such as there's no power steering pump mount on a B8.5.
CTUC from Q5 is 272hp variant; CTUD is for the SQ5. These are the same enough as the CTUB. Compressor is the same as CGXC/CTUB; I'm sure the exhaust manifolds are different.
CGX_ and CTU_ from the C7.0 A6 and A7 should work too.

[Memehotep]

Thanks! Nice information. Now, the power steering pump mount is something I'm assuming I could transfer from my old motor? Or did they not make drilled holes in the block casting from switching to electric steering assist?

[Smac770]

Shane's posts would imply it can be worked out; this is one of those specifics that has to be worked out. Can't say for the 3.0T. For the 2.0T, between B8.0 and B8.5, it's the accessory bracket/oil filter stand (need the B8.0 version to have a place to mount the power steering pump) and the crank position sensor (changed from 2-pin to 3-pin) that have to be carried over. I'm sure somewhere here is a reference of someone swapping a 3.0T engine B8.0<->B8.5.

[Shane Horning]

Correct you will need to swap over accessory brackets, a few sensors and some vacuum lines, pcv hose going to air intake, secondary air injection connect line and a few other odds and ends but its absolutely possible. Did it many times

[fastboatster]

Correct you will need to swap over accessory brackets, a few sensors and some vacuum lines, pcv hose going to air intake, secondary air injection connect line and a few other odds and ends but its absolutely possible. Did it many times

curious about pcv valve itself. b8 and b8.5 pcvs are supposed to maintain slightly different crankcase vacuum and have different p/ns. if I recall correctly, b8.5 will have slightly larger crankcase vacuum. seems like that doesn't really matter. I know that b8.5 has a way smaller oil pump compared to b8 but doesn't seem to make any difference either.

[Smac770]

CCBA was updated to the later spec through an updated PCV and ECM software update. The new PCV implements a 150 mbar (4.4 inHg) crankcase vacuum level. I don't know what the original crankcase vacuum level was for the 3.0T. OP should probably put a vacuum gauge on the dipstick and see what his crankcase vacuum is at warmed up idle. The TSB on the subject (2030197/15) lists the old vacuum level software as 8K0907551A and 8K0907551B. And the new vacuum level software as 8K0907551D ver 0003 or later.

2.0T went through the same thing, and putting the wrong PCV on for the ECM software version can create rough idling, etc. Ours was a change from 20 mbar to 100 mbar.

[fastboatster]

CCBA was updated to the later spec through an updated PCV and ECM software update. The new PCV implements a 150 mbar (4.4 inHg) crankcase vacuum level. I don't know what the original crankcase vacuum level was for the 3.0T. OP should probably put a vacuum gauge on the dipstick and see what his crankcase vacuum is at warmed up idle. The TSB on the subject (2030197/15) lists the old vacuum level software as 8K0907551A and 8K0907551B. And the new vacuum level software as 8K0907551D ver 0003 or later.

2.0T went through the same thing, and putting the wrong PCV on for the ECM software version can create rough idling, etc. Ours was a change from 20 mbar to 100 mbar.

yes, but the updated b8 pcv is still a different p/n compared to b8.5. Visually they look identical, though.

[Smac770]

Parts catalog mentions the original CCBA PCV is 30 mbar. So both the 2.0T and 3.0T had a 5x increase in the vacuum level.

The 3.0T 30 mbar PCV is 06E103547 F > Q > AC.

The 3.0T 150 mbar PCV is 06E103547 H > S > AB > AH.

The 3.0T evo (CRE) 150 mbar PCV is 06E103547 N > AD > AF.

So there is only the single replacement part today for either pressure configuration. And then a separate one for the CRE engines (D4.5 A8, C7.5 A6/A7) which were not used in B8.

[Memehotep]

Ok, so Smac, in your opinion is it better to go with the older style block which would be an easier install. Or are the newer blocks much more reliable as it would be worth it to forego the process of swapping everything over. I found a CCBA with 108k miles with complete harness and engine ECU, but am on the fence of a CTUA with 139k miles which is about 1k$ less

[Memehotep]

Oh, and also there's a CTUC with 134k miles and comes with a 6 month warrantee and delivered to my house free, being the cheapest option

[fastboatster]

Parts catalog mentions the original CCBA PCV is 30 mbar. So both the 2.0T and 3.0T had a 5x increase in the vacuum level.

The 3.0T 30 mbar PCV is 06E103547 F > Q > AC.

The 3.0T 150 mbar PCV is 06E103547 H > S > AB > AH.

The 3.0T evo (CRE) 150 mbar PCV is 06E103547 N > AD > AF.

So there is only the single replacement part today for either pressure configuration. And then a separate one for the CRE engines (D4.5 A8, C7.5 A6/A7) which were not used in B8.

isn't that what I said unless I understood you wrong? b8 and b8.5 still have different pcv p/ns. Audi parts catalog lists AC as compatible with b8 only, and AH is b8.5. But, given the TSB you posted, it looks like b8 can be switched to b8.5 pcv if you are not happy with oil consumption level, right? wonder if would have been better off putting the AH revision PCV into my b8. Wonder if 003 software I have is not quite okay with AC PCV rev

[Smac770]

Exactly, if you brought in your CCBA complaining about excess oil consumption, just like the 2.0T, first thing they are going to do is update the PCV on it. Which means the revised version (150 mbar) and an ECM software update. You need to evaluate the complete software part number + revision, not the revision alone.

Meme, put a vacuum gauge on your dipstick tube and find out if you're 30 mbar or 150 mbar. Numbers on the table, or it's all just random guessing. If you're running 30 mbar, add the PCV to the things you need to port over. As noted previously, you should be able to review the ECM software info and determine if it was updated for 150 mbar as well.

[fastboatster]

Exactly, if you brought in your CCBA complaining about excess oil consumption, just like the 2.0T, first thing they are going to do is update the PCV on it. Which means the revised version (150 mbar) and an ECM software update. You need to evaluate the complete software part number + revision, not the revision alone.

Meme, put a vacuum gauge on your dipstick tube and find out if you're 30 mbar or 150 mbar. Numbers on the table, or it's all just random guessing. If you're running 30 mbar, add the PCV to the things you need to port over. As noted previously, you should be able to review the ECM software info and determine if it was updated for 150 mbar as well.

Yes, I do have a 150mbar software and 30mbar PCV. I guess that explains why fuel trims are very slightly (2-3%) positive at idle. This is my second 30mbar pcv after the engine replacement, the first one burned lots of oil but current one doesn't.