Chrysler 3.5 HO V6 swap (Page 1/33)
seajai AUG 03, 06:21 PM
Got my engine swap car today.



It's a 2003 300m with the 250hp HO v6 and an auto transaxle.



This swap has been talked about in the past, but as far as I can tell, has yet to be done. I was curious about a longitudinal setup, and the thread started by engine man a while back got me thinking. I like the Audi V8 he is doing but I want an automatic, and that engine never came with a non-quattro auto trans so the computer stuff was going to be a pain.

The 3.5 measures 19" from cam cover to bell housing flange, and the trans is 5.5" from bell housing to axle center-line, for a total of 24.5". This is pretty close to the firewall-to-axle measurement in the stock engine bay so I think it's going to be a good fit. I am currently researching my computer options. I would like to use the factory computers, I can get the immobilizer programming removed from the factory pcm. I'm not sure how the bcm and pcm will react when I start removing modules from the bus though. I have been unable to find the needed info on the subject so I am just going to start experimenting on my car and see what happens. The backup plan is a megasquirt / megashift setup.
This is uncharted territory and sure to be a challenge, but I love a good challenge.

[This message has been edited by seajai (edited 09-28-2023).]

Ang84Indy AUG 03, 06:52 PM
This sounds interesting, I'm going to be watching this thread.
Macs86GT AUG 03, 08:17 PM
I have a Concorde with that engine in it and it makes it move quite nicely. It would really move a fiero nice and has a smooth power band.
Austrian Import AUG 03, 09:02 PM
First time I saw that engine in a friends car I was wondering about fitting it to a Fiero. Wish it came with a manual, but I guess can't have everything.
Erik AUG 04, 01:34 AM
Ive changed a few of the failure prone 2.7s for customers and every one of them had a quirky transmission that ends up failing. If yours is the same trans I would beware they also have apretty high failure rate. That being said the 2.7engine is a pretty powerful v6 for its size, I can imagine what a 3.5 would be like.
Austrian Import AUG 04, 01:49 AM
First time I saw that engine in a friends car I was wondering about fitting it to a Fiero. Wish it came with a manual, but I guess can't have everything.
Reallybig AUG 04, 04:42 AM
Just looked up some interesting related info here:

http://www.allpar.com/mopar/V6/35.html
Fierofreak00 AUG 04, 01:50 PM

quote
Originally posted by Erik:

I've changed a few of the failure prone 2.7's for customers, and everyone of them had quirky transmissions that ended up failing. If you have the same trans, I would beware, as they have a pretty high failure rate.

I edited your post to fix the errors in your grammer


Really? You're kidding right?? I've been a Gold Certified Chrysler tech for 14yrs, and have been at a dealership since this transmission came out. And in that time, I can count on two hands and a foot, how many times I have seen the 42LE fail. It is used behind all the LH bodies, as well as the Prowler and in my professional opinion is one of the best transmissions Chrysler has used (within recent years, the torque flight not included). I have 265k on my 99 Intrepid and it has had the pan opened once to change the filter. And my mother-in-laws Intrepid has over 165k on it, and I have never touched that trans either. -Jason

[This message has been edited by Fierofreak00 (edited 08-04-2012).]

pontiackid86 AUG 04, 02:26 PM
L:ets just put it this way, My 1st time over 100 MPH (more like 140MPH) was inb my dads chrysler 300M special. Very very powerful engine and also with the right exhaust it sounds like an infinity.. Now jayson... Lol I do have to admit we have been through 2 transmissions in the 300M with now 145K on it.

[This message has been edited by pontiackid86 (edited 08-04-2012).]

Erik AUG 04, 03:07 PM

quote
Originally posted by Fierofreak00:
Really? You're kidding right?? I've been a Gold Certified Chrysler tech for 14yrs, and have been at a dealership since this transmission came out. And in that time, I can count on two hands and a foot, how many times I have seen the 42LE fail. It is used behind all the LH bodies, as well as the Prowler and in my professional opinion is one of the best transmissions Chrysler has used (within recent years, the torque flight not included). I have 265k on my 99 Intrepid and it has had the pan opened once to change the filter. And my mother-in-laws Intrepid has over 165k on it, and I have never touched that trans either. -Jason




Thats nice that you havent had any problems.The 3 that I worked on, none newer than a 2000 had transmissions that either would fail to shift out of second or fail to shift at all. Which caused the engine to rev high in combination with the poor oiling oil sludge problem the 2.7 had which would cause the engine to fail with a rod knock or windowing the block .I ended up changing the engines and transmissions in all. Its been a few years since I researched what trans was used with that engine. IIRC there were several different ones used but I could be wrong. I did a little research at the time and found that there were tons of complaints and Chrysler was dragging their feet on covering the losses .It seemed there was class action lawsuits against Chryler on these issues. Im not trying to knock the engine or trans because I had thought about using the combo for a Fiero swap as well although I was planning on doing a 2.7 rather than a 3.5 which I am not aware of having any problems, engine wise.

To add to my experience with these engines I just looked up some pictures I had taken during a trans engine replacement and it was a 2000 Concorde with the 3.2 that had a messed up trans and a trashed engine. I dissasembled the junked engine and found the sludge in the bottom of the pan along with a bad timing chain and of course a trashed rod.

[This message has been edited by Erik (edited 08-04-2012).]