Posted By: 360view
Not a typical 4L Jeep straight 6
Posted By: Grizzly
Re: Not a typical 4L Jeep straight 6 - 10/10/20 05:13 AM
Boy, did they hit the nail on the head calling the 4.0 "lazy" and being known for "lack of power". 
Up until now I thought all those engines were good for was donating their EFI to Slant Sixes?
I'm impressed and that was a VERY good read, thanks 360View!
The video is one of the best engine videos I've ever seen. Learned alot from watching it.
Up until now I thought all those engines were good for was donating their EFI to Slant Sixes?
I'm impressed and that was a VERY good read, thanks 360View!
The video is one of the best engine videos I've ever seen. Learned alot from watching it.
Posted By: Tom_440
Re: Not a typical 4L Jeep straight 6 - 10/10/20 06:40 PM
Very impressive!!!
That would be interesting in my TJ, but I don't think it would fit. But if it did, it would destroy the trans, transfer case, drive shafts and axles. But it would be fun!!!
That would be interesting in my TJ, but I don't think it would fit. But if it did, it would destroy the trans, transfer case, drive shafts and axles. But it would be fun!!!
Posted By: larrymopar360
Re: Not a typical 4L Jeep straight 6 - 10/10/20 09:51 PM
A bit of a tangent here. My brother in law is looking to buy older Wrangler. What year was the last year for the bullet proof 4.0 liter straight six?
Posted By: Pacnorthcuda
Re: Not a typical 4L Jeep straight 6 - 10/10/20 11:13 PM
Originally Posted by larrymopar360
A bit of a tangent here. My brother in law is looking to buy older Wrangler. What year was the last year for the bullet proof 4.0 liter straight six?
2006, then it was replaced in 2007 by the horrible 3.8 minivan engine. In 2012 they came out with the MUCH better 3.6 v6.
Posted By: larrymopar360
Re: Not a typical 4L Jeep straight 6 - 10/11/20 03:22 PM
Okay, I didn't know all the 4.0 were good. I thought maybe the later version might not have been the same engine internally. Thanks.
Posted By: Tom_440
Re: Not a typical 4L Jeep straight 6 - 10/11/20 07:53 PM
I'm swapping motors in my 2000 TJ because of a cracked head. The '99 - 2001 Jeep 4.0's had a issue with heads occasionally cracking, letting antifreeze into the oil, and cooking the bearings. The issue was fixed in 2002 with TUPY heads.
https://www.jeepforum.com/forum/f9/i6-head-problems-1999-2001-a-1452146/#:~:text=yup.,out%20to%20have%20ductility%20problems.
The cracked head issue isn't really common, and its not hard to swap heads, but just something to keep in mind when you are shopping.
https://www.jeepforum.com/forum/f9/i6-head-problems-1999-2001-a-1452146/#:~:text=yup.,out%20to%20have%20ductility%20problems.
The cracked head issue isn't really common, and its not hard to swap heads, but just something to keep in mind when you are shopping.
Posted By: Pacnorthcuda
Re: Not a typical 4L Jeep straight 6 - 10/11/20 07:57 PM
Originally Posted by Tom_440
I'm swapping motors in my 2000 TJ because of a cracked head. The '99 - 2001 Jeep 4.0's had a issue with heads occasionally cracking, letting antifreeze into the oil, and cooking the bearings. The issue was fixed in 2002 with TUPY heads.
https://www.jeepforum.com/forum/f9/i6-head-problems-1999-2001-a-1452146/#:~:text=yup.,out%20to%20have%20ductility%20problems.
The cracked head issue isn't really common, and its not hard to swap heads, but just something to keep in mind when you are shopping.
https://www.jeepforum.com/forum/f9/i6-head-problems-1999-2001-a-1452146/#:~:text=yup.,out%20to%20have%20ductility%20problems.
The cracked head issue isn't really common, and its not hard to swap heads, but just something to keep in mind when you are shopping.
I’ve heard head gaskets and cracks are about the only issue with the 4.0 and as we all know it’s a somewhat common issue amongst the straight six world of ALL makes. The big thing with 4.0’s is DONT LET THEM OVERHEAT.