I have read a lot about the new Pentastar 3.6 V6 in many Chrysler Jeep products. They often compare it to the predecessor: the 3.8L V6 which was in the Jeep Wrangler before the Pentastar came out. But where does the 3.7L V6 fit in that was the only engine in the Jeep Liberty and the base engine in the Jeep Grand Cherokee. BTW I read that the Liberty is in its last year.
Jeep 3.7 V6 is related to what other Chrysler V6?
- Thread starter Jim Spahr
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The 3.7L V-6 is based on the 4.7L Powertech V-8. It's a SOHC 2-valve engine found only in some Jeep and truck models. It's been phased out over the last few years and I do think that after the Liberty is gone, the 3.7L will be as well.
http://en.wikipedia.org/wiki/Chrysler_PowerTech_engine
I never have liked this engine. It's based on a 90 degree V-8 design, so it's a 90 degree V-6 design, which is never optimal for a V-6. It uses balance shafts to quell the vibes. It's also a rather low-tech design with two valves per cylinder, despite having overhead camshafts. For what you get, I think the OHV 3.8L V-8 engine is a better deal in most regards. Because the 3.7L was often used where the 4.7L is optional, it makes sense because transmission bellhousings can be the same, engine mounts can be the same, etc.
But I think it says something that Jeep used the 3.8L in its 2008 Wrangler, which was as near to a clean-slate design as it gets in the modern vehicle era. They could have used the 3.7L, but likely chose the 3.8L for its better NVH characteristics, smaller footprint (more compact), and excellent mid-range torque.
The 3.6L Pentastar obviously eclipses both engines in nearly every regard.
http://en.wikipedia.org/wiki/Chrysler_PowerTech_engine
I never have liked this engine. It's based on a 90 degree V-8 design, so it's a 90 degree V-6 design, which is never optimal for a V-6. It uses balance shafts to quell the vibes. It's also a rather low-tech design with two valves per cylinder, despite having overhead camshafts. For what you get, I think the OHV 3.8L V-8 engine is a better deal in most regards. Because the 3.7L was often used where the 4.7L is optional, it makes sense because transmission bellhousings can be the same, engine mounts can be the same, etc.
But I think it says something that Jeep used the 3.8L in its 2008 Wrangler, which was as near to a clean-slate design as it gets in the modern vehicle era. They could have used the 3.7L, but likely chose the 3.8L for its better NVH characteristics, smaller footprint (more compact), and excellent mid-range torque.
The 3.6L Pentastar obviously eclipses both engines in nearly every regard.
Good explanation Hokie. What's the lineage of the new 3.6?
Originally Posted By: Hokiefyd
I never have liked this engine.
Me neither. I have driven a few vehicles with the 3.7 and they are pure dogs. Vehicles are not good on gas, yet make next to no power either. Not a winning combo. They are usually somewhat reliable at least.
I never have liked this engine.
Me neither. I have driven a few vehicles with the 3.7 and they are pure dogs. Vehicles are not good on gas, yet make next to no power either. Not a winning combo. They are usually somewhat reliable at least.
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.
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.
So that answers one of my questions. I always wondered if the 3.8 was just a slightly bored out 3.7L. It wasn't. So now I wonder if many hot rodders put the 4.7L V8 in their Liberty since it would have bolted up to the trans. The 4.7 had its detractors also. It was thirsty and a dog. So you liked the 3.8. I keep hearing on this forum that it was not economical and now they are saying it was an oil burner! The 3.7 is to the 4.7 as the Chevy 4.3 V6 is to the Chevy 5.7L V8. They lopped off two cylinders. So what do you say to those on the forum who didn't like the 3.8 V6 because it was slow and very thirsty?
the 4.7 and 3.7 are loosely based on a mercedes v8 from the 70's
Originally Posted By: Jim Spahr
So you liked the 3.8. I keep hearing on this forum that it was not economical and now they are saying it was an oil burner!
I personally did. I had two of the 3.3/3.8 V-6 engines and both were smooth and quiet. Fairly refined for OHV V-6 engines. They had a good meaty torque curve in the mid range. They weren't stump pullers, and they wouldn't scream to 6,000 rpm, but they were good engines for what they were. Some of the 3.8L engines did consume lots of oil. I've read on this forum that the Mexican engine plant installed piston rings upside down. Could be, I don't know.
Originally Posted By: Jim Spahr
So what do you say to those on the forum who didn't like the 3.8 V6 because it was slow and very thirsty?
Both the 3.8L and 3.7L are going to be slow and relatively thirsty compared with better engines (such as the Pentastar for instance). But the 3.7L offered no real benefit to the consumer over the 3.8L. But it was unrefined and thrashy. If Chrysler would have commonized their engines a little better, they might have been able to use the 3.8L with some of the RWD transmissions that the 3.7L was using and ditched that 3.7L V-6 engine. They eventually did this with the Wrangler I guess, because the 3.7L would have been an obvious choice, given they were using it in other RWD-based Jeeps.
So I don't know why they ended up using the 3.8L in the Wranglers, but I liked the move. It's all moot with the new Pentastar now, but it's an interesting discussion topic nonetheless.
So you liked the 3.8. I keep hearing on this forum that it was not economical and now they are saying it was an oil burner!
I personally did. I had two of the 3.3/3.8 V-6 engines and both were smooth and quiet. Fairly refined for OHV V-6 engines. They had a good meaty torque curve in the mid range. They weren't stump pullers, and they wouldn't scream to 6,000 rpm, but they were good engines for what they were. Some of the 3.8L engines did consume lots of oil. I've read on this forum that the Mexican engine plant installed piston rings upside down. Could be, I don't know.
Originally Posted By: Jim Spahr
So what do you say to those on the forum who didn't like the 3.8 V6 because it was slow and very thirsty?
Both the 3.8L and 3.7L are going to be slow and relatively thirsty compared with better engines (such as the Pentastar for instance). But the 3.7L offered no real benefit to the consumer over the 3.8L. But it was unrefined and thrashy. If Chrysler would have commonized their engines a little better, they might have been able to use the 3.8L with some of the RWD transmissions that the 3.7L was using and ditched that 3.7L V-6 engine. They eventually did this with the Wrangler I guess, because the 3.7L would have been an obvious choice, given they were using it in other RWD-based Jeeps.
So I don't know why they ended up using the 3.8L in the Wranglers, but I liked the move. It's all moot with the new Pentastar now, but it's an interesting discussion topic nonetheless.
what would we have ended up with if chrysler had down sized the V-8 440, to a V-6. just a dream.
I remember that one of the versions of the Jeep Wranglers had a factory V6 from Buick, I believe. Never got to drive one.
Ha
These were clean sheet engines designed at JTE in chrysler.
The non-HO would run a 15.4 in AWD WJ Limited, hardly a dog, the HO were a tad quicker.
The 3.8 was a left over from the 80's V6 with pushrods.
Originally Posted By: Chris142
the 4.7 and 3.7 are loosely based on a mercedes v8 from the 70's
These were clean sheet engines designed at JTE in chrysler.
The non-HO would run a 15.4 in AWD WJ Limited, hardly a dog, the HO were a tad quicker.
The 3.8 was a left over from the 80's V6 with pushrods.
Originally Posted By: Chris142
the 4.7 and 3.7 are loosely based on a mercedes v8 from the 70's
Originally Posted By: Jim Spahr
I remember that one of the versions of the Jeep Wranglers had a factory V6 from Buick, I believe. Never got to drive one.
You used to be able to get an AMC Jeep Cherokee with a GM 2.8L V-6. Those were real pigs.
I remember that one of the versions of the Jeep Wranglers had a factory V6 from Buick, I believe. Never got to drive one.
You used to be able to get an AMC Jeep Cherokee with a GM 2.8L V-6. Those were real pigs.
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.
Originally Posted By: Hokiefyd
Originally Posted By: Jim Spahr
I remember that one of the versions of the Jeep Wranglers had a factory V6 from Buick, I believe. Never got to drive one.
You used to be able to get an AMC Jeep Cherokee with a GM 2.8L V-6. Those were real pigs.
I think he's referring to The 225 Buick v6 from the 60s
Originally Posted By: Jim Spahr
I remember that one of the versions of the Jeep Wranglers had a factory V6 from Buick, I believe. Never got to drive one.
You used to be able to get an AMC Jeep Cherokee with a GM 2.8L V-6. Those were real pigs.
I think he's referring to The 225 Buick v6 from the 60s
Originally Posted By: Chris142
the 4.7 and 3.7 are loosely based on a mercedes v8 from the 70's
Only thing they had in common with Mercedes was that both were V8's.
Other than that, the Chrysler "PowerTech" 4.7 and 3.7 were in final design, development and early production before Daimler took over Chrysler in mid 1998.
the 4.7 and 3.7 are loosely based on a mercedes v8 from the 70's
Only thing they had in common with Mercedes was that both were V8's.
Other than that, the Chrysler "PowerTech" 4.7 and 3.7 were in final design, development and early production before Daimler took over Chrysler in mid 1998.
Originally Posted By: Hokiefyd
Originally Posted By: Jim Spahr
I remember that one of the versions of the Jeep Wranglers had a factory V6 from Buick, I believe. Never got to drive one.
You used to be able to get an AMC Jeep Cherokee with a GM 2.8L V-6. Those were real pigs.
When my dad bought his Cherokee in 1985, he actually opted for the anemic 2.5L I4 because he hated the 2.8L. Apparently the company he worked for had a 2.8L S-10 truck for errands and general use and he was not a fan.
Originally Posted By: Jim Spahr
I remember that one of the versions of the Jeep Wranglers had a factory V6 from Buick, I believe. Never got to drive one.
You used to be able to get an AMC Jeep Cherokee with a GM 2.8L V-6. Those were real pigs.
When my dad bought his Cherokee in 1985, he actually opted for the anemic 2.5L I4 because he hated the 2.8L. Apparently the company he worked for had a 2.8L S-10 truck for errands and general use and he was not a fan.
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 3.7 is pretty darn reliable. My roommate has an '04 Liberty with about 220K miles on its original unopened 3.7.
It leaks a lot of oil, but doesn't seem to burn much. The oil light comes on frequently due to the leaking. At first, he would add just enough oil to get the light to go off. I finally got him to just go ahead and add a full quart. I attempted to teach proper use of the dipstick, but that ain't happening. The body and suspension are falling apart, but the 3.7 soldiers on, along with the unhappy transmission that went over 180K before getting its first flush to resolve a violent shudder (amazingly the flush worked).
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 3.7 is pretty darn reliable. My roommate has an '04 Liberty with about 220K miles on its original unopened 3.7.
It leaks a lot of oil, but doesn't seem to burn much. The oil light comes on frequently due to the leaking. At first, he would add just enough oil to get the light to go off. I finally got him to just go ahead and add a full quart. I attempted to teach proper use of the dipstick, but that ain't happening. The body and suspension are falling apart, but the 3.7 soldiers on, along with the unhappy transmission that went over 180K before getting its first flush to resolve a violent shudder (amazingly the flush worked).
Never had a moment's issue with the 3.7 in Liberty's. We put 100K on a 2002 - first year Liberty - never used a drop of oil. My wife now has a 2010 Liberty - same thing. Zero oil comsumption, runs well, and very dependable.
Granted the gas mileage is not superb, but it is a 4 wheel drive SUV. We drove it 400 miles or so recently - all expressway. 70-75 mph with AC running -- came back at almost 21mpg. Didn't think that was that bad.
Granted the gas mileage is not superb, but it is a 4 wheel drive SUV. We drove it 400 miles or so recently - all expressway. 70-75 mph with AC running -- came back at almost 21mpg. Didn't think that was that bad.
Originally Posted By: SLCraig
Originally Posted By: Hokiefyd
I never have liked this engine.
Me neither. I have driven a few vehicles with the 3.7 and they are pure dogs. Vehicles are not good on gas, yet make next to no power either. Not a winning combo. They are usually somewhat reliable at least.
I honestly never got the 3.7 myself.
It does have a little more power than the 3.9 Magnum as well as more torque (albeit at 4000 rpm) but it seems like it would be cheaper to upgrade the 3.9 to Essex 4.2 and Chevrolet 4.3 output levels than to develop the 3.7. Not to mention the 3.9 Magnum had to be cheaper to build.
It's just funny to look at the 90° V6es' output on paper. The Intrepid 3.5 made more horsepower than all of them and made as much torque as the Ford Essex 4.2 at only 300 more rpm.
I know why GM and Ford stuck with their pushrod 90° V6es for as long as they did. They were cheap to make. That's why I can't figure out the PowerTech 3.7 It still wasn't better in any aspect over the GM and Ford. Little better than the 3.9 but the Magnum was durable if gutless and had been in production long enough to be cheap. Seems like it would have been cheaper to maybe update the timing with a cam phaser and do some engine management and flow work rather than develop a new engine.
Originally Posted By: Hokiefyd
I never have liked this engine.
Me neither. I have driven a few vehicles with the 3.7 and they are pure dogs. Vehicles are not good on gas, yet make next to no power either. Not a winning combo. They are usually somewhat reliable at least.
I honestly never got the 3.7 myself.
It does have a little more power than the 3.9 Magnum as well as more torque (albeit at 4000 rpm) but it seems like it would be cheaper to upgrade the 3.9 to Essex 4.2 and Chevrolet 4.3 output levels than to develop the 3.7. Not to mention the 3.9 Magnum had to be cheaper to build.
It's just funny to look at the 90° V6es' output on paper. The Intrepid 3.5 made more horsepower than all of them and made as much torque as the Ford Essex 4.2 at only 300 more rpm.
I know why GM and Ford stuck with their pushrod 90° V6es for as long as they did. They were cheap to make. That's why I can't figure out the PowerTech 3.7 It still wasn't better in any aspect over the GM and Ford. Little better than the 3.9 but the Magnum was durable if gutless and had been in production long enough to be cheap. Seems like it would have been cheaper to maybe update the timing with a cam phaser and do some engine management and flow work rather than develop a new engine.
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