Jeep 3.7 V6 is related to what other Chrysler V6?

[L_Sludger]

Originally Posted By: demarpaint
I like my 3.7L Liberty, no oil use, runs great. Maybe old school but no problems like some of the new Chrysler engines. My buddy has a Mexican assembled 3.8 L in a Wrangler and its an oil guzzling pig. I guess opinions vary.

The 3.8 in the company 2007 Caravan consumes a prodigious amount of oil as well - but I do believe that it is smooth and powerful.
Side note, the van typically returns about 20mpg in fleet use between several drivers. On a lark, I wanted to see what the van was capable of, and ended up getting 34.5mpg on a 120 mile trip from San Diego to Orange County and back with it, after I switched from the OEM plugs to Autolite Iridiums. But that was also with me using every hypermiling trick I had in my repertoire,

 

[Jim Spahr]

I rented a Jeep Grand Cherokee with the 3.7 V6 for a 1400 mile round trip. It was a loaded car with two Golden Retrievers, and lots of luggage and it was surprisingly peppy in performance. The only complaint I had was the steering was overly sensitive on the highway. I was really pleased and surprised at the performance of the 3.7.
I like V6 and V8's with pushrod engines. They are not only cheap to make, they are easy and cheap to work on. They are durable and reliable as well. I don't like VVT,DI, AFM, variable displacement and so on. GM has had amazing success with their LSx line of pushrod engines in both performance and gas efficiency.

 

[caravanmike]

my 3.7L has returned 23mpg on the highway (vacation) and consumes no oil! high tech/low tech? who cares. it is reliable and gets the job done.

i still don't know why u would create a motor and only get 10 years production out of it? i would think a better choice would be one of their exsisting v-6's.

as far as why the 3.8L went in the wrangler i read an article that stated it was all about production capacity. the 3.8L had way more production capacity with the minivans selling 400,000+ a year in the good economy. they didn't want to expand the 3.7L's line because the 3.3/3.8L's multiple lines could absorb the production increase with out expansion. their was already 3-4 lines making the 3.3/3.8L's.

 

[meep]

3.8 was also best candidate as a 4.0 replacement due to most similarities in torque.

I have owned a 3.3, a 3.8, and a 3.7.

the 3.3/3.8's were smooth as silk and neither consumed oil. The 3.8 now has about 90k on it.... it leaked alot from pan and covers but after new gaskets it has done just fine.

The 3.7 had a neat exh note but it had a lot of vibrations. It never consumed a drop of oil and was a reasonable powerplant for the grand chero we had it in. Towed mid-size (3000lb) loads just fine. It had pretty pronounced valve tap and even some pin slap early on in its life but aside the nuisance it was ok. Electrical gremlins started popping up like a rash and we ditched the 3.7 as a result.

I think the 3.8 is the best of the bunch.

I spent some time in the 3.5 and it was a great motor in the LHS vehicles. dual throttles, intakes, exhausts (2 into a single muffler), that car was //fun// to toss around.

M

 

[SwampSurvivor]

Meep, even though the 3.8 and 4.0 have very similar torque curves, the 3.8 can't even begin to compare to the 4.0. It just feels complete gutless.

The 2.8 available in the cherokees were the GM v6. The AMC I4 not only had fuel injection, but made almost the same amount of torque and horsepower.

The 3.7 and 3.8 are pretty crummy engines. The 3.7 sludges up and eats head gaskets, the 3.8 spins main bearings a lot in the Jeeps but is reliable in the minivans.

From what I've heard, the 3.7s always had more grunt than the 3.8 ... I'm guessing it's because they had a mechanical throttle and the 3.8 in Jeeps had the non functional electric throttle?

Jeep did use a few Buick V6s over the years. For a while, they were using the Buick 3.8 v6 - my understanding is that GM thought there was no market for a V6 and licensed it to AMC for a while.

Jeep died when they got rid of the 4.0 as far as I'm concerned.

 

[01rangerxl]

Originally Posted By: Miller88
The AMC I4 not only had fuel injection, but made almost the same amount of torque and horsepower.


For at least the first year of Cherokee production the 2.5 came with a one barrel carb.

 

[Hokiefyd]

Originally Posted By: Miller88
Meep, even though the 3.8 and 4.0 have very similar torque curves, the 3.8 can't even begin to compare to the 4.0. It just feels complete gutless.


I can only assume that you haven't driven a similar vehicle (like a Wrangler) with both engines to compare. The straight-six 4.0L doesn't hold a candle to the 3.8L V-6 when it comes to overall driveability. The only area where the 4.0L would out-grunt a 3.8L is if towing a trailer and the engine was limited to 3,000 rpm for some reason. The 3.8L is a far more workable engine than the 4.0L. It makes the Jeep so much more lively.

My folks had a 2006 TJ (4.0L). My neighbor has a 2008 JK (3.8L). And now my parents have a 2012 JK (3.6L). The 3.6L out-shines either of the other engines pretty handily, but the difference between the 3.8L and the 4.0L is pretty dramatic as well, with the scale tipped heavily in favor of the 3.8L in almost every driving situation.

 

[SwampSurvivor]

I've driven all sorts of Jeeps - 4.0 TJs, XJs - with various gearing. Also numerous JKs with the 3.8. Going 55 in my parents current JK, in 6th gear, on the flat, you can floor the gas pedal and it'll just keep going 55.

My XJ with the 4.0, 3.55 gears and 32'' tires (just as tall as their rubicon), can take off pretty good at 55 and not even kick out of OD

The 3.8 has, at best, the same amount of power as the AMC 150 had in the wranglers. 3.8s can't get out of their own way. Completely gutless engine.

 

[Jarlaxle]

Note: your XJ is a solid 1000lbs LIGHTER than a new Wrangler Rubicon! It needs to spin to make it, but the 3.8 has MORE power than the 4.0 HO. Comparing it to the 2.5 4-cylinder borders on the stupid.

 

[Spazdog]

Originally Posted By: Miller88
Meep, even though the 3.8 and 4.0 have very similar torque curves, the 3.8 can't even begin to compare to the 4.0. It just feels complete gutless.

...

Jeep died when they got rid of the 4.0 as far as I'm concerned.


I assume we are talking about the Inline AMC 4.0.

The Dodge Nitro had a 4.0 V6 based on the Intrepid SOHC 3.5L. I've never seen one in a Liberty though.

It's more or less the same vehicle so maybe I just haven't seen one yet.
It was also in the Volkswagen Routan and Chrysler Pacifica.

It makes as much torque as GM's 4.3 and something like 60 more horsepower. That's not Pentastar horsepower numbers but it is a few more pounds of torque at about 800 less rpm.

Don't know why they would use the 3.8 in the Wrangler over this engine other than the pushrod 3.8 was cheaper to build.

 

[Jarlaxle]

I Wonder if the OHC V6 was too wide.

 

[Hokiefyd]

Originally Posted By: Jarlaxle
I Wonder if the OHC V6 was too wide.


That'd be a reasonable assumption, until they shoe-horned the Pentastar 3.6L DOHC V-6 into the Wrangler. Maybe the Pentastar is more compact than the 3.5/4.0 SOHC engines.

 

[Norm Olt]

Originally Posted By: Nick R
Originally Posted By: Indydriver
Good explanation Hokie. What's the lineage of the new 3.6?


Brand new, clean sheet design, not related to any other engine in the lineup.


Very much related to the newer Mercedes 3.5L V6 (M276) and V8 (M278): cousins, if you prefer.

Cheers!

 

[Spazdog]

Originally Posted By: Hokiefyd
Originally Posted By: Jarlaxle
I Wonder if the OHC V6 was too wide.


That'd be a reasonable assumption, until they shoe-horned the Pentastar 3.6L DOHC V-6 into the Wrangler. Maybe the Pentastar is more compact than the 3.5/4.0 SOHC engines.


I doubt it.

They got the SOHC 4.0 shoehorned sideways into a Cara-Routanvan. Maybe they just didn't deem it "Jeep worthy"

...Nitro-worthy, but not Jeep worthy as I still haven't found an example of a Liberty with a SOHC 4.0.

 

[SwampSurvivor]

The liberty wasn't a "street performance" model - that's why it never got the 4.0.

Edit: 4.0 SOHC V6


Originally Posted By: Jarlaxle
Note: your XJ is a solid 1000lbs LIGHTER than a new Wrangler Rubicon! It needs to spin to make it, but the 3.8 has MORE power than the 4.0 HO. Comparing it to the 2.5 4-cylinder borders on the stupid.


However, my Cherokee has twice the miles, the same size tires, much taller gearing and an automatic transmission with 2 less gears.

In all honesty, I'd like to give a throttle cable'd 3.8 a chance.

With that said, there's no excuse for the excessive oil consumption and bearing spinning that the 3.8s are known for.

 

[Jarlaxle]

Originally Posted By: Spazdog
Originally Posted By: Hokiefyd
Originally Posted By: Jarlaxle
I Wonder if the OHC V6 was too wide.


That'd be a reasonable assumption, until they shoe-horned the Pentastar 3.6L DOHC V-6 into the Wrangler. Maybe the Pentastar is more compact than the 3.5/4.0 SOHC engines.


I doubt it.

They got the SOHC 4.0 shoehorned sideways into a Cara-Routanvan. Maybe they just didn't deem it "Jeep worthy"

...Nitro-worthy, but not Jeep worthy as I still haven't found an example of a Liberty with a SOHC 4.0.


And it fitting the Caravan has what, exactly to do with engine bay space in a JK Wrangler?!

 

[Spazdog]

It's a short engine compartment front to rear. One can safely suggest that if it fits transverse in a short compartment minivan, it might fit mounted longitudinally in a Wrangler.

That and there is considerable room between the fenders and engine on the SOHC 4.0 in the Nitro compared to models with the 3.7

 

[Hokiefyd]

Originally Posted By: Miller88
In all honesty, I'd like to give a throttle cable'd 3.8 a chance.


In a light XJ, I think it'd be a hoot.

Originally Posted By: Miller88
With that said, there's no excuse for the excessive oil consumption and bearing spinning that the 3.8s are known for.


I absolutely agree with you on that. The 3.8L in our old 2007 Chrysler van never burned anything. Maybe I got an American-made engine, who knows.

 

[SwampSurvivor]

Originally Posted By: Hokiefyd
Originally Posted By: Miller88
In all honesty, I'd like to give a throttle cable'd 3.8 a chance.


In a light XJ, I think it'd be a hoot.

Originally Posted By: Miller88
With that said, there's no excuse for the excessive oil consumption and bearing spinning that the 3.8s are known for.


I absolutely agree with you on that. The 3.8L in our old 2007 Chrysler van never burned anything. Maybe I got an American-made engine, who knows.


Nope, in a JK. It wouldn't be a fair comparison putting it in a different vehicle. The lack of power isn't really as bad as the reliability issues. It's a jeep, not a race car.

My Cherokee isn't terribly light, I have two large tool boxes full of tools, a full sized steel wheel spare (weighs about 70 pounds), spare axle shafts, spare front and rear drive shafts, extra battery, small air compressor, gallon of (coolant, ATF, gear oil, motor oil) ...

Yes, your caravan has an american made engine. The RWD 3.8 were assembled in Mexico and had rings put in wrong, pistons in the wrong spot, etc.

With that said, the 3.8 belongs more in a Jeep than the 3.6. An aluminum car engine has no place in a utility vehicle.


Originally Posted By: Spazdog
It's a short engine compartment front to rear. One can safely suggest that if it fits transverse in a short compartment minivan, it might fit mounted longitudinally in a Wrangler.

That and there is considerable room between the fenders and engine on the SOHC 4.0 in the Nitro compared to models with the 3.7


Weren't there AMC 4.0 test mules around? The engine bay is MUCh larger than it needs to be for the 3.8.

Which engine is taller? 3.7, 3.6 or 3.8?

 

[Hokiefyd]

Originally Posted By: Miller88
Yes, your caravan has an american made engine. The RWD 3.8 were assembled in Mexico and had rings put in wrong, pistons in the wrong spot, etc.


A lot of guys with minivans had Chrysler replace the long blocks also; many of the FWD versions consumed a lot of oil. For some reason, the 3.3L never had that reputation, but the 3.8L sure did, FWD or RWD.

Originally Posted By: Miller88
With that said, the 3.8 belongs more in a Jeep than the 3.6. An aluminum car engine has no place in a utility vehicle.


I recommend driving a 2012 Wrangler with the 3.6L. It's a wonderful engine. My folks' Wrangler is a Rubicon model, with a 6" lift and 35" tires. Dad is president of the Family Motor Coach 4WD Association. They host a rally at least once a month. The 3.6L is a winner of an engine, and will rock crawl with any of them.

Here they are, in Utah I believe.