4.0 to 3.0 swap?

Geeshik · Aug 10, 2008

Hi. If i was going to swap my 1990 4.0 for a similar year 3.0, would i be able to use the same trans, mounts, and computer? It's an automatic 4x4.

What are good aspects of both engines? I'm trying to decide and fuel economy and reliability are major factors. I would outfit my rig with a light duty plow for Wisconsin winters (a few driveways; nothing commercial), and it would mostly see light duty hauling (yard waste, lumber, etc.)

I have heard alot of bad things about the 4.0, and i have owned two now... a 1998 SOHC Explorer that seemed okay except for a noisy timing chain and tons of vacuum leaks on goofy plastic intake manifold, and now a 1990 with a motor that is shot (It has 170,000 miles on it, and the guy i bought it from got rid of it because he couldn't get it running and had no time to replace it with the low mileage 1991 4.0 that he picked up.)

The truck is nice, stock, with little rust. The paint is faded out, but it's better than most vehicles it's age up here in the rust belt. I just am not sure if a 4.0 is the best thing for my needs. Not to mention the fact that it takes up so much room under the hood of the truck...

Which brings me to my next question... Can i eliminate the EGR and Catalytic Converter? Will this hurt anything in the engine? I have heard arguments both ways. It doesn't have to pass emissions.

Hahnsb2 · Aug 11, 2008

Trans and computer, no, unsure about the mounts. Won't hurt anything to remove the cat but it wont help either, unsure about the EGR. Find another 4.0.

turbo cat · Aug 11, 2008

so he gave you another good 4.0 with the sell? If so drop it in and go or go to craigs list or the yards you can find good 4.0s for under 150$. In my 02 the 4.0 is alot stronger than the 3.0. the fatory heads are an issue with the earlier 4.0s however there are replacements and you have to try hard to break the bottom end. Oh and the 4.0 sohc has its different issues

KELLY88 · Aug 11, 2008

Converting to a 3.0 would take more time and money than just dropping in another good 4.0. Plus you say you're going to be running a plow? If that's the case you'll want the 4.0 torque. It's a strong, reliable motor and the gas mileage is pretty good for an engine that size. My 97 4.0 with almost 200K on the clock with a lift and 33s still gets around 16-19 mpg around town.

Geeshik · Aug 11, 2008

Thanks for the info guys.

It wasn't exactly what i wanted to hear, but if sticking with the 4.0 that i got saves me some $, i am probably going to use it. I have a wife and a 2 year old girl and i am going to school this fall for mechanical design. Money is very tight. The main reason i would lean toward a 3.0 is mostly my experience with them... I would say they are Ford's best V6. The other reason would be fuel economy, but i got a little 1996 Escort that i can get economy out of.

The guy i bought the truck from said that he bought it with a tick. It gradually got worse, and all of a sudden, one day it wouldn't run.

It did come with another engine and trans (the old trans was slipping, he told me) from a 1991 Explorer that was wrecked. Supposedly it is low mileage, but i think he kept the engine outside and i didn't see anything to protect it from the elements. I think it's going to work. All i can do is try, right?

Hahnsb2 · Aug 11, 2008

As far as absolute bullet proof the 3.0 is hard motor to kill. The 4.0 makes so much better low end torque over the 3.0 it isn't even funny, IMHO it's a good engine if properly maintained. Hell, my 2.9 which is regarded as probably the worst V6 ever has held up to my 40K miles of pure abuse and is still hangng in there and it doesn't tick (2.9 tick is waaay more common than 4.0 tick).

Ranger44 · Aug 11, 2008

If you are going to be plowing the 4.0 would be better with the same gearing as a 3.0. But with extra low gearing a 3.0 can perform. It's a rever and likes high rpms, and with the lower gearing.....will stay in it's powerband.

It will be an easier swap for a 4.0. A 3.0 could easily be swapped in if you have a donor vehicle.

As for reliability, the 3.0 is downright indestructable(as long as there is coolant and oil in it). The 4.0 OHV (not the same in your newer explorer OHC) does have a "slight" upper oiling problem. But these engines have served people way beyond 200,000 miles and keep chugging. Proper maintenance is key to any engines life.

As for fuel economy, the 3.0 is a slightly better. I've heard as good as 24mpg. But the best I've ever heard of from a 4.0 is 20mpg.

But the choice is up to you. The best I can do is offer my opinion.

Hahnsb2 · Aug 11, 2008

AllanD claims 22 MPG with his 4.0 and thats with too low of gears, I know 22-24 MPG is attainable in the right rig with a 4.0 and has been done before. 3.0s I've heard up in the 27MPG range but 23-25 is average. I'd take the extra torque over minor fuel economy gain any day.

Geeshik · Aug 12, 2008

Thanks again.

Without bashing GM, I would have to say a 2.9 is waaay better than a 3.1 or 2.8 motor. My dad has a lifted '88 ranger 4x4 with a 2.9 and it's great... The trans is cracked though.

I had an '87 BII 4x4 with a 2.9 and i sold it because my wife hated the way it rode on the highway. (I have to admit, there were a couple of windy days that got me sick too.) The only problem i had was when i was wheeling and i pinched off the exhaust with the front driveshaft. It stalled, and didn't want to start. Oh, and the stupid EGR tube rusted through and i had a nasty sounding exhaust leak, but mechanically, the engine was solid. I had it for a few years. I bought it from a guy after his girlfriend rolled it over. They fixed it up, but they didn't replace the driveshaft... Someone cut it and welded it out of phase. It made a nasty grinding sound in second, so they got rid of it. I threw in an aftermarket driveshaft with REAL u-joints and never had a drivetrain noise. I did have to also replace a freeze plug on the back of the engine though... It was leaking coolant out of the manual trans. But those were minimal. i never had a tick or a damaged head or anything like that.

Anyway, i love Rangers and Ranger based vehicles. They are VERY dependable, and VERY tough for what they are. My '98 Explorer was okay, but there's nothing like a Ranger. I only wish they made a 4-door ranger in the 80's or 90's... I want something i can put a child-seat into.

Thanks for the advice though. I'll stick with the 4.0. I'm looking forward to getting this one going. It's hard when you have two econoboxes and no truck. (i have an escort and my wife drives a focus.)

93Ranger4x4 · Aug 27, 2008

i've blown up a 3.0 before......Altho i wasnt exactly easy on it,and before it blew i drove it for about 2 monthes with is blowing smokelike crazy and with a misfire, Just dump a qrt of oil in it and go, but sadly it didnt hold up forever, it finally took acrap on me while in town,dropped all cylinders but 1 or 2,couldnt move unless it was in low lock and then finally it just stopped all together lol. But yeah,i would go with anther 4.0,much easier to swap in then messing with swapping a 3.0 in there/

just my .02 cents

4.0 to 3.0 swap?

Geeshik

New Member

Hahnsb2

New Member

turbo cat

New Member

KELLY88

New Member

Geeshik

New Member

Hahnsb2

New Member

Ranger44

New Member

Hahnsb2

New Member

Geeshik

New Member

93Ranger4x4

New Member

Sponsored Ad

Sponsored Ad

Staff online

Members online

Member & Vendor Upgrades

Latest posts

Truck of The Month

Recently Featured

Follow TRS On Instagram

Latest Album Photos

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store

Sponsored Ad

Sponsored Ad

Sponsored Ad

Amazon Deals