Is the 4.0L really that bad?

[ArmyGuy45]

I keep reading about people wanting to swap motors but what is really wrong with it? I have seen some high mileage and they last forever, so why swap?

The money you put into a swap you could just put into the 4.0 to get the same power and keep a long lasting engine.

[Brasscatz]

No, it's not bad at all. It's actually one of the most bulletproof engines ever made.

People usually want to swap for reasons including wanting more power or wanting diesel. The other reasons could be that these 4.0's are getting harder and harder to find and if theirs go out, it may be cheaper to swap to something else.

[ArmyGuy45]

No, it's not bad at all. It's actually one of the most bulletproof engines ever made.

People usually want to swap for reasons including wanting more power or wanting diesel. The other reasons could be that these 4.0's are getting harder and harder to find and if theirs go out, it may be cheaper to swap to something else.

I thought about that but with Cherokees, Wranglers, some Grand Cherokees I would think the 4.0L is still moderately easy to find/rebuild.

[07Negative]

The 4.0 is old technology too. For its displacement, it's really low in power. I personally rather like the 4.0. But given the chance to do a 5.3L Vortec swap. I'm on it! You can easily get 400hp & Torque out of it. That would make for a rocket ship of an XJ. And some serious torque with an Atlas 4.

[XJ Wheeler]

Power, mileage, and just being different. Without stroking or boosting there's not a ton of power to be had over stock, so the cost of doing that probably puts the swap in peoples minds. We all know the fuel economy isn't the best and i guess people put it together a couple more mpgs is worth thousands for an engine swap. Doesn't really make much sense unless you're getting a good bit more per gallon. And lastly, "because no one around me has one, it'll be cool to stand out."

Engine swaps are something to think long and hard about. Many projects like that have been dormanted or sold just because the owner didn't know what he/she was getting into.

Bottom line is the 4.0 is a great, reliable engine with the torque needed for what we do. With upgrades it can have more, but from the many reports I've seen you should be glad to get 20 mpg. An engine swap (unless you somehow get most of the pieces free) will never pay for itself, or will be so far off you may not have the vehicle then anyway. To me, i'd rather stroke and turbo my 4.0 and that will be my power, economy, difference...

Sent via messenger pigeon - i talk, he types.

[ArmyGuy45]

Power, mileage, and just being different. Without stroking or boosting there's not a ton of power to be had over stock, so the cost of doing that probably puts the swap in peoples minds. We all know the fuel economy isn't the best and i guess people put it together a couple more mpgs is worth thousands for an engine swap. Doesn't really make much sense unless you're getting a good bit more per gallon. And lastly, "because no one around me has one, it'll be cool to stand out."

Engine swaps are something to think long and hard about. Many projects like that have been dormanted or sold just because the owner didn't know what he/she was getting into.

Bottom line is the 4.0 is a great, reliable engine with the torque needed for what we do. With upgrades it can have more, but from the many reports I've seen you should be glad to get 20 mpg. An engine swap (unless you somehow get most of the pieces free) will never pay for itself, or will be so far off you may not have the vehicle then anyway. To me, i'd rather stroke and turbo my 4.0 and that will be my power, economy, difference...

Sent via messenger pigeon - i talk, he types.

Wouldnt you want to supercharge it so you have power at lower RPM's?

[Joliet Johnny]

I like the Jeep 4.0 so much that if I ever get that 48-54 4 door Chevy car I want, I may give it the heart of a Jeep? If my 4.0 dies I may consider a swap.

[nickyg]

"Dance with the one that brung ya" keeps popping in my mind.

Jeep has been making straight sixes longer then I've been alive. they gotta know what their doing by now.

[XJ Wheeler]

Wouldnt you want to supercharge it so you have power at lower RPM's?

With the turbos they have these days i'm sure you could set it up to have power in somewhat lower rpms too. Plus a supercharger puts strain on the engine where a turbo uses what the engine is wasting. This leads to better economy. If you notice a lot of manufacturers have been doing smaller turbo'd engines to help meet regulations.

Sent via messenger pigeon - i talk, he types.

[denverd1]

It a good long-lasting engine but dated technology. various power adders don't do much to the bottom line. including stroking and opening up flow restrictions. IMO its why jeep brought out the 3.7. much more efficient engine and cheaper to keep compliant

[Firemanray]

The 4.0 is a tough, bullet proof engine. My son and I wheeled our's (130,000 miles + ) like we stoled it for several years then he started using it as a DD. He did ultimately blow it up, I'm not sure what happened but I'm sure a loud stereo was somehow part to blame. I put a Thunderbolt engine in it and it's been purring ever since.

Carnage:
http://i223.photobucket.com/albums/dd11/firemanray21/0709132030_zpsf72af7ce.jpg (http://s223.photobucket.com/user/firemanray21/media/0709132030_zpsf72af7ce.jpg.html)
http://i223.photobucket.com/albums/dd11/firemanray21/0709132031_zpsdec3e70f.jpg (http://s223.photobucket.com/user/firemanray21/media/0709132031_zpsdec3e70f.jpg.html)