1stGlance

Is it possible to put 4.0 T in to replace 4.2 ? Trying to find out NOW not for "future project". Car is in shop already!! Thank you for any input !!

Jack88

In theory, you should be able to. I don't know how many modules need to be replaced and how many need to be recoded.

Ravill

It seems like this would be in the "throw enough cash at it until it works" category.

A 8

Why would you want to do it? The 4.2 is really good as is and if you want the 4.0T why not just get a car with it in the first place? I cant see how you would get your hands on a 4.0T engine and put it in another D4 and making it work financially, not to mention all the control units and re-coding issues you would likely get. If you did it and wanted to sell no one would buy it until its really, really old and cost nothing.

Jack88

I was running the numbers of buying a totaled 4.0t, doing the swap, and reselling the car with the 4.2 in it's place. The cost would mostly be in labor, but it could be done for a fair bit cheaper than selling a currently owned 4.2 and finding a 4.0t that's comparable, if you are competent enough to do it yourself or have an indie mechanic who knew exactly how to do it.

derfA8L

Swapping the engine might be the easiest part of the whole deal. You'd have to install the special variable cylinder engine mount vibration dampeners which may entail a different sub-chassis structure; there is also the Variable cylinder noise canceling setup that runs through the sound system; a host of software mapping upgrades, not to mention possible changes to the 8-speed transmission to deal with the increase in torque; and I'm not sure about possible changes to the cooling system.

Perhaps it's doable, but I have a sneaking feeling that it's just not that simple, and goes well beyond the engine alone.

RED HORSE

The good old days of dragging an old 34 Ford into the garage and buying a few adapters and sticking a small block Chevy in it are long gone. My guess is that engine swamps just one year to the next with the "same" engine would be pretty involved today.

MP4.2+6.0

+1. Never gonna happen. 10 years ago it was already at the point of being next to impossible and get it street titled with all the right smog and all. Today i would say next to impossible, maybe even to get it to a reasonable driving condition let alone DMV type compliance issues. Think about even the basics of swapping over the ECU that will be different, the related harness, the security programming on the ECU, how it talks with the MMI dynamic stuff, what the ECU tells the TCU, and on and on.

Ravill

Since the OP hasn't posted yet, I bet he's come to the same conclusion.

1stGlance

Yes same conclusion not worth the time/expense!! Extended warranty will replace my 4.2 with a new factory fresh long block and that is how it will go. Thank all of you that replied - much appreciated! Cheers....