Chrysler, Dodge, and Plymouth 3.3, 3.5, 3.8 Liter V-6 Engines
by Michael A. Cole except where noted
Introduced in 1990, the 3.3L was the first Mopar designed and built V6 engine to see duty in front wheel drive Chrysler vehicles. [A 3.9 liter engine, based on the LA series V8s, was the first Chrysler made V6, but it only saw truck duty.] The 3.3 was even successful as a 255-horsepower racing engine (as used in Shelby Can Am cars)
Joined by a 3.8L version the following year, the 3.3/3.8L series features a traditional cast-iron block, aluminum head, overhead-valve design while also incorporating newer technologies such as sequential, multiple-port fuel injection (SMPI) and an integrated electronic ignition system supplanting the mechanical distributor, rotor and coil systems of the past.
Also in the 3.3/3.8L series, a 3.5L aluminum-block version saw early duty in the LH platform series. It was later replaced by an all-aluminum 24-valve 3.2L V6 featuring a unique (at the time) coil-over-plug design which eliminated the need for secondary ignition cables. The 3.2 itself was dropped, leaving the 2.7 and 3.5.
With ample torque available early in the rpm range, the 3.3/3.8L series was well suited to its primary application as a source of power for Chrysler's award winning minivans. These engines were also used in the Dynasty, New Yorker, Fifth Avenue and Imperial models until those vehicles were later replaced by the LH platform series, which was eventually powered by the aforementioned all-aluminum 2.7/3.2L V6s.
3.3/3.8L Engine Chronology
The 3.3/3.8 are the only remaining Iaccoca-era power plants still seeing active duty [the ancient AMC straight-six and 360 V8 both precede Iaccoca...and both will be gone before the 3.3]. Now entering their second decade of service, the 3.3/3.8L series has been continuously revised with the 3.3L gaining 33 hp and the 3.8L gaining a healthy 65 hp since inception. (They are currently only available in minivans.)
| Engine | Years Used | Horsepower (bhp) | Torque (lb-ft) | Notes |
|---|---|---|---|---|
| 3.3L | 1990-1993 | 150 @ 4800 RPM | 180 @ 3600 RPM | A 147hp version was used in Dynasty and New Yorker. |
| 3.8L | 1991-1993 | 150 @ 4400 RPM | 213 @ 3600 RPM | Used in Fifth Avenue and Imperial. |
| 3.3L | 1994-1995 | 162 @ 4800 RPM | 194 @ 3600 RPM | Power increases for 1994 via revised intake plenum. |
| 3.8L | 1994-1995 | 162 @ 4400 RPM | 213 @ 3600 RPM | Power increase for 1994 via revised intake plenum. No longer used in cars. |
| 3.3L | 1996-2000 | 158 @ 4850 RPM | 203 @ 3250 RPM | Revised intake and exhaust for enhanced torque. Horsepower drops slightly but torque increases and peaks earlier. |
| 3.8L | 1996-1997 | 166 @ 4300 RPM | 227 @ 3100 RPM | Revised intake and exhaust systems for enhanced power and torque. |
| 3.8L | 1998-2000 | 180 @ 4300 RPM | 240 @ 3100 RPM | Significant boost in power and torque. |
| 3.3L | 2001-on | 180 @ 5000 RPM | 210 @ 4000 RPM | Extensively revised with a new variable intake system, higher compression ratio, and new piston heads. |
| 3.8L | 2001-on | 215 @ 5000 RPM | 245 @ 4000 RPM |
Eras of power (Jim Gathmann)
There are three basic eras which produce different levels of power. The early units (1990-1993 or so) were pretty good, but in 1994/1995 the HP jumped a good 10-12 HP. This is due to changes in the intake manifold design and changes in fuel injection system. This results in a slight but noticeable increase in power from the stock 3.3/3.8.
The recent models have much more power thanks to new intake manifolds, electronics, compression ratio, etc.
Transmission and block has been pretty constant. The transmission of the newer models is just a newer A604.. now the newer models work much better (due to electronics differences, internal differences- better material mostly... basically a good rebuild of the older A604 will bring it up to about current 41TE standards...).
The 3.3 Dynasty (1992, 1993), isn't bad. It can do highway speeds without much work, and certainly can move a heavier car. In terms of from stop to go, I've played around with using 3 or all 4 gears.. in either case, the low end torque of the 3.3 is really not bad. There is a reason why the 3.3 was used as a model for making the 3.5.
The 3.8 New Yorker/Imperials is slightly more powerful and are much better from dead stop (idle) to highway speeds. The local ricers try to hide from the 3.8s as they are surprised by the power of a stock, heavy car....
Most of the changes to the 3.3/3.8 were electronic (however the mechanics did change slightly... the rocker breakage problem was fixed by a design change in late 1991) in the later years, while up through the late 1990s it mechanically oriented - different intake manifolds and such.
You are stuck with the A604/41TE as the 3.3/3.8 requires a bell housing that only specific A604s got. Basically the A604's bell housing was changed so it can work on the 3.3- a 3.0 A604 will not work on a 3.3. Now it may be possible to get a 3.0 and 3.3 A604 and note the differences, and duplicate the differences for a 3 spd, etc.
[Paul wrote: The 3.3 / 3.8 share the same bolt pattern for the transmission as the 3.0. What differs is the cut out in the bell housing for the 3.0, as the water tube from the water pump comes out under the intake at the top section of the bell housing.]
In 2006-07, the 3.8 liter engine was retuned, yielding lower horsepower and torque ratings but a flatter torque curve for more of a punchy feel (pictured in the Jeep Wrangler, where gas mileage of the 3.8 was equal to that of the old 4.0 straight-six.)
The 3.5 liter engine according to Chrysler (for the LH)
When introduced in 1993, the 3.5 was the most powerful naturally-aspirated engine in any Chrysler-built sedan, with peak horsepower of 214 at 5,800 rpm and 221 foot pounds of torque at 2,800 rpm (it would eventually go to over 250 horsepower). Mechanical noise levels were the lowest of any engine ever measured by Chrysler. This was an exciting engine compared to just about any competitor.
Like other major systems on the LH, the 3.5-liter engine was designed to meet or exceed the powerplant Chrysler engineers considered the best in this segment -- in this case, the 3.2-liter 24- valve engine in the Acura Legend.
Nestled in a compact, 60-degree block of cast iron with"over square" bore and stroke, Chrysler's 3.5-liter engine had the highest compression ratio -- 10.4:1 -- of any Chrysler-built engine in recent memory.
It uses bottom-feed fuel injectors, a first for high-volume passenger cars (the Dodge Viper also had bottom-feed fuel injection). The bottom-feed fuel injection system has a three-fold rationale, according to Howard B. Padgham, powertrain engineer. It was selected not only to accommodate the LH's sloping front profile, but also because at the time (early 1989) it was believed the industry as a whole was moving in this direction and, finally, bottom-feed injection would improve "hot" engine re-starts and eliminate stumble.
'This truly is a premium engine and as 'bullet proof' as we could make it. At this stage, I'm more confident about the 3.5 than any engine I've ever been involved with," said Padgham - who had at the time 28 years in Chrysler engineering, 15 devoted to engines, including Chrysler's 2.2, 2.2 Turbo and 2.5 four- cylinder engines, as well as the 318 V-8 and the 360 V-8 special, high-performance"police" engine package. "The 3.5 has the basic ingredients you'd expect from a premium engine: forged crankshaft, free-floating piston pins ... those sorts of things."
LH's trend-setting Cab Forward exterior design presented challenges. "It's sloped like the hood to fit just like a hand in the underside of a glove," mused Padgham. "Notice the shape of the cylinder head, the design of the intake manifold. They reflect the space we had to work with."
The"north-south" powertrain layout permitted more space flexibility in the engine compartment and, in addition, provides the option of easy adaptation for potential, future applications to rear-wheel or all-wheel drive.
The 3.5 liter engine was used exclusively in the Chrysler LH models for a time, but eventually made it to the Dodge Intrepid R/T, where it was dropped down to 242 horsepower - but ran on regular gas. It then spread through the line, appearing in 242 - 250 hp form in the Chrysler Pacifica, Dodge Charger and Magnum, Chrysler 300C, and, with 232 hp due to the small engine bay, in the 2008 Dodge Avenger/2007 Chrysler Sebring. Horsepower ratings varied from application to application, and in the 300M, from year to year - and with a slight increase in the 300M Special.
Marcel wrote in 2008, regarding the Dodge Challenger’s implementation of the 3.5 liter V6:
What you've seen before on these 3.5 engines is the Dual Plenum/Dual Throttle Body setup, where each three-cylinder bank had its own intake manifold and separate throttle body.
Now they've changed that to a Triple Plenum / Dual Runner Manifold fed by a single throttle body. This system is basically two different manifolds in one, controlled by runner valves. The long runner flow path is used at low rpms to gain additional torque. The short runner flow path is used at high rpms to gain additional horsepower. The dual Runner manifold is mentioned on the website but the benefits are not explained.
3.3 liter V6 “teething troubles”
[Name of writer withheld]
We motor room mechanics were a little disappointed when the engineer came down with the first prototype parts for the 3.3. We were expecting an overhead cam-high tech-high performance engine, and were shocked when we pulled out a bag containing push rods!
Somebody had done a survey of potential customers, so the "cost effective" approach was taken. Ford's Taurus engines and GM's 3.8 used pushrods, so why not us?
We were paying a high premium for Mitsubishi's 3.0L V6, and Trenton Engine had room for another assembly line, so it was a no-brainer as far as the necessity and where it would be built. We had some problems early on with valve stem finish which was quickly fixed, a bigger problem was thrust bearing failure.
We were getting some engines coming in to tear down with incredible end play, you didn't need a dial micrometer to know which ones were bad. Our manager grabbed me and three other mechanics and we spent the next two days at Detroit Metro Airport checking crank end play on Snappy rental cars with the 3.3 engine. Most were okay, but an occasional one would produce not 3 or 4 or 5 thousandths end play, but 100+ ! We immediately went to a wider thrust face. Has not been a problem since. [These early problems affected only a relatively small number of very early engines.]
I had a real battle with an engineer in regards to the head bolt washers and the ensuing CYI approach he took. The 2.2 and 3.3 used the same head bolts and washers; a decision was made to widen the head bolt washer to increase the clamping area, but on the 3.3, the wider washer could hit the valve spring that is next to the oil feed cam tower. And they did.
[One engineer] told me that noisy tappet replacement was our fifth biggest warranty item on the 3.3, but when they got the suspect parts back to engineering, they weren't noisy. I fought to get a service bulletin written on this, to check for interference before doing a costly cam/tappet replacement, but another engineer [tried to cover up with] the claim that it "helped attenuate" engine noise. On a visit to Trenton Engine, I found the line worker who assembled the heads and asked him why he didn't notify Engineering about this. "I did, but was told not to worry about it," he replied...
Another problem is oil leaks. Anytime you bolt aluminum to iron, the gasket in between is compromised, due to the expansion differences between the two metals. This is particularly evident in the chain case module gasket. The gasket moves over time and creates a gap just above the oil pan rail, and it makes a mess. Lower intake gaskets leak in the corners. An upgraded gasket was designed with longer, tapered rubber ends that was supposed to end the use of RTV, but RTV will always be a necessity on that application.
Other notes
Jim Gathmann wrote: The early years of the 3.3 did have problems with the rockers and the oiling system. Apparently they fixed this by (or in) the second year of production.
Dan Rose wrote: "I am a Dodge Dynasty owner who has one of the first 3.3 engines ever to come off the line. The pulleys on the (at least the very early) 3.3 are made out of plastic, they break easily."
The 3.3 liter engine was fitted out for compressed natural gas when used in minivans, starting in 1994.
“atwork” wrote that a 3.0 liter version of the engine was being tested for China as of January 2008.
The 3.3 liter V6 engine as adapted for Chrysler's LH series
The fundamental change necessary to apply the 3.3-liter, overhead valve, V-6 engine to the LH platform was strategic -- turning it from the transverse "east-west" mounting of this same engine in certain other Chrysler passenger cars.
As with the 3.3-liter engine, the 3.5 was manufactured at Chrysler's Trenton, (Mich.) Engine Plant.
"The block was altered only in respect to the attaching points," said Padgham. "Another thing, we couldn't use the wrap-over intake manifold, so we came up with a unique manifold that gives us more torque. We also designed new exhaust manifolds, but the base engine stays the same. The water outlet elbow is new and the accessory drive system is unique. It's a two-belt drive, one for the alternator and power steering pump and a second belt for the air conditioning."
In addition to these alterations, LH engine engineers also designed powerplant-bending struts between the block and transmission to provide more rigidity and stiffness. A three-point mounting system also was introduced. The oil pan is the only identical component with the 3.5-liter.
In its LH application, the 3.3-liter engine delivered a peak 153 horsepower at 5,300 rpm and 177 pound feet of torque at 2,800 rpm.
Francois Castaing said:
It was a challenge because when we started the LH program in January, 1989, the only engine we knew we had for sure was the 3.3-liter V-6. But we felt if the car was to be a success, it needed a brand new, high power, high technology engine.
The engine people on the team knew they had never designed a new engine that quickly (40 months). Also, the investment would be quite high. There also was the fear that when you commit a lot of money for the company, you want to commit it right and not make a mistake. Still, the team and engine people within the team realized the LH would not be a success unless the new engine was there at the same time we launched the car.
So instead of giving in to the negatives that it couldn't be done, that we couldn't get the technology, the slickness, the power, the low emissions, the fellows said, 'let's go for it.' They challenged themselves, they were convinced the 3.5 engine was an absolute cornerstone for the car.
General notes - 3.3, 3.5, 3.8 litre V6 engines
Ed Hennessy wrote: "[The 3.3] is a 100% Mopar design, introduced in 1990. It has a timing chain, not a belt. It's pretty reliable from all indications. Decent power and low end torque. All are 60 degree V6s."
The 3.5 (another 100% Mopar design) has a timing belt. The 250 hp version has an aluminum block. Douglas Miske wrote that the change interval for the timing belt is 84 months or 105,000 miles / 170,000 km.
| 3.3 | 93 mm bore | 81 mm stroke | OHV, roller lifters, short skirt |
| 3.5 | 96 mm bore | 81 mm stroke | OHC, 24 valve, deep skirt, cross bolted mains (many changes in second generation) |
| 3.8 | 96 mm bore | 86.9 mm stroke | Bored and stroked 3.3 |
Jim Gathmann wrote: "when the 3.3 and 3.8 were tested for turbo applications, the engine blew its self to bits. The 3.3 and 3.8 were both used as prototype engines for the Dynasty police cruisers, and the idea was a police package Dynasty- with beefed up parts, a 3.8 and a turbo would be the Mopar replacement to the M-bodies (as they ended in 1989...). The problem was that the 3.3/3.8s would literally break apart on the bottom end during what Chrysler has called 'moderate boost.'"
Note: for those who believe the 3.5 is a Mitsubishi engine, Kevin Cobabe sent us the following chart:
| Chrysler 3.5 | Mitsubishi 3.5 (e.g. Diamonte) | |
|---|---|---|
| Power | 250 hp @ 6400; 250 lb-ft @ 3900 | 205 hp @ 5000; 231 lb-ft @ 4000 |
| Bore x Stroke | 3.78 x 3.19 | 3.66 x 3.38 |
| Compression | 9.9:1 | 9.0:1 |
Bob Sheaves clarified the 3.5 engine's relationship
Bob wrote that the order of creation was:
- 3.3L pushrod to replace 3.0 Mitsubishi engine in Dynasty and New Yorker
- 3.8L pushrod for more torque in minivan AWD and New Yorker/Dynasty (bored/stroked 3.3)
- 3.5L SOHC 1st generation- High output 3.3 for first gen LH, all aluminum
- 3.5L SOHC 2nd Gen- Higher output 3.5 for 1gen LH, 2nd gen LH, Prowler, minivans (never installed in these- they stuck with the 3.8L for the minivans)
- 2.7L Higher efficiency, smaller displacement version of the second generation 3.5
- 3.2L increased torque 2.7, midline engine between current 3.5 and low end 2.7
"91redbaron" wrote: The 3.5 had a rather interesting intake setup. There were two separate intake manifolds for the left and right side cylinders with their own throttle-bodies (interesting throttle linkage and cabling there). So in a way it was like two in-line 3-cylinders that were joined at the crank.
Common problems
For the most part, this engine series is very reliable. See the introductory part for some issues.
Not starting
The starter appears to be a weak point and may fail while making clicking noises instead of turning the engine over. Also see the not-starting page.
Rocker arms / rocker arm pedestal breakage
One problem - relatively common but still rare overall - with the 3.3 and 3.8 is rocker arm pedestal breakage.
John "Auto Tech" wrote,
"I honestly don't know of any way to prevent it from happening but I do know of a repair that can be done 'on the car' and it works without replacing the head. (To begin with it needs to be understood that the head is "already ruined", the proper repair is to replace the entire head.)
That being said, this makeshift repair has worked on six or seven heads that I have seen with my own eyes. You need to remove any existing threads from the broken pedestal (so a longer bolt will pass through) and drill out the head below to make new threads. The drilled hole WILL break through the head casting so the helicoil installation needs to be precise. I don't recommend this head repair for your average do-it-yourself person and if you have any doubts then fix it right and replace the head.
- Remove the rocker shaft and the broken tower.
- Drill out any threads in the tower.
- Drill out the head below the broken tower and install a Heli-Coil in the head. Now you can install a longer bolt through the rocker shaft and tower that will hold the entire assembly to the head.
This repair is a cost cutting way to get the job done without having the expense of replacing the head. This is NOT the proper fix for this problem and should only be attempted by someone who's skilled in drilling, tapping, and installing helicoils. Since the area is not only subject to high heat levels but is also a high stress point on the head (thus the original pedestal breaking) this repair needs to withstand extreme conditions daily. I'm sure you will understand the proceedure in full once you remove the valve cover and verify that this is the noise you’re hearing.
One final tip, be sure to consider how long the engine has been run since the noise began. I've done this repair with great success but only if the engine hasn't been run once the pedestal breaks. The clattering noise is created when the pedestal is being slammed into the head at its point of breakage. Every time it hits the head it causes metal particles to break off and enter the engine. If too much metal has gotten into the oil, the engine will not last very long after the repair is complete.
An engineer wrote: "if a mechanic reinstalls the rocker shaft on an engine that still has the lifters 'pumped up,' he must allow for them to be bled down or he risks breaking the shaft. Maybe in this instance the pedestal will fail."
Karl Williams wrote: "if they drill the hole deeper and tap for the original metric tap in the rocker tower, you can use the small head bolt for the fix. It is long enough and has the same thread as the original rocker shaft bolt. Chrysler recognized the problem and beefed up the rocker tower casting in the later model years. "
Jim Gathmann wrote in 2003: "I hear a lot about the rocker arm breakage problems on early 3.3s.... (even though such problems are rare and can be fixed forever by increasing the bore sizes on the top end oiling system...) CompCams makes a "ProMagnum Rocker Arm" which comes with a lifetime warrenty against breakage and is made of chromemoly steel. I suspect using these in place of the OEM arms and forged pushrods would result in a much more solid setup which would be more boost friendly, less likely to brake (in the case of the older 3.3s) and last a lot longer."
Rough idling
Kestas: If the rough idle is accompanied by a drop in engine speed when the air conditioner goes on, it may be that the engine is not getting enough air. Clean the throttle body, then check to make sure the idle air controller is clean and has full travel to the open position. (Take off the idle air controller, check for free movement, and give it a good visual inspection to make sure it is clean. It may need a shot of carb cleaner on the moving surfaces.
FCT: Check to make sure that the fuel rail recall was done (where applicable).
Mark: The engine is prone to intake manifold gasket problems that can cause a rough idle.
"Mopar Man and Woman:" "Remove and clean both throttle bodies. Synchronize throttle bodies. Remove IAC (ASI) [idle air speed/automatic idle speed] motor, but do not spray or soak with cleaner. Wipe tip off with cleaner on shop towel. Spray cleaner into bore in manifold. Make sure that hose that goes to air cleaner duct to intake right behind IAC is not blocked, collapsed etc. This is the source for air flow to the IAC on the 3.5L.
Perform minimum air flow test with DRB or other Scanner - should be 500-650rpm. If above, suspect vac leak, if low you have throttle body problems. At full operating temp, curb idle, what are desired IAC steps? Try cylinder balance test with scanner. If one or two cylinders are slightly different than rest, suspect intake manifold gasket failure. Also, after each repair, before starting, reset adaptive memory in PCM with scanner."
Cesar: "Just thought I share a similar problem I had with my 97 Eagle Vision w/3.5L that drove a lot technicians crazy, including field support folks, for 8 working days! The problem was one of the camshaft was slightly out of alignment in respect to its sprocket. This problem started after a water pump housing ("rear timing belt cover") was replaced and fuel rail recall performed. The symptoms I had after this effort was rough idle similar to the problem you've described. To verify valve timing on this engine there is a camshaft alignment special tool 6642 that must be used."
There may also be a problem with the MAP sensor - click here for instructions on diagnosing this.
There may also be a problem with the EGR sensor (repalcement guide)
Exhaust flange noise
"Sounds like metal springs pulling apart every time I step on the gas pedal." Master mechanic John Mastriano wrote: "I've found that you can get rid of this noise permanently by running a round wire brush to clean off any rust build-up in the donut area of the exhaust manifold, then coat this entire area with never-seize (the silver stuff that gets all over everything) before installing the [new] donut."
Click here for other possible causes and solutions
Maintenance
“On the Caravan 3.3 (1990s), it took me 3 hours for that one rear plug alone; all the rest were pretty accessible Disconnect the battery before working on the back three plugs! While under there doing them I got some arcing and sparking (no apparent damage). I would not recommend doing your back plugs unless you have lots of patience and small arms (plus a box of bandages).”
Ervin added: “On the Caravan with the 3.3, take the bolt out of the front engine mount by the radiator and let the engine rotate forward as far as possible and then set the parking brake. Watch for clearance as you push the car in park and it will work. You can then use a socket extension straight down on the plugs and reach them easier.”
Performance
There aren't many bolt-on performance upgrades for the 3.3/3.5/3.8 family. Mike Rodick did mention that one company is selling a nitrous system at about $800. The wisdom of using this is unknown.
See our article on 3.3-powered Shelby Can Am cars
Hank Heykoop wrote about removing the air cleaner restrictor to gain more power (also suggesting upgrading the muffler): "The purpose for the restrictor is for noise control. It didn't increase much after removing it. You must first remove the air box then the restrictor can be unsnapped by pushing it out. This applies to the 1991 through 1995 vans [with 3.3 engines]. My fuel mileage and top end performance were slightly improved. ... The restrictor is a cylindrical piece snapped into the input end of the actual airbox."
Mike Rodick wrote: "I took my 91 Dynasty[3.3] with 140,000 miles to the local drag strip one weekend. I beat a V8 Ford Explorer twice, and almost had an early 80s Camaro V8 beat. ( Got me by .06 sec). The 3.3 holds her own!!" His best time was:
60 ft. - 2.4829 sec
330 ft. - 7.0943 sec
1/8 th mi. - 10.9268
1000 ft. - 14.2379 at 73.24 mph
Don Martin wrote a page on how to make a minivan-specific 3.3 performance air intake.
A turbo-3.3 owner, Nenad Sudar, wrote:
I would like to clear up some info on my turbocharged 3.3l V6 Dodge Dynasty. I have replaced pistons with Ross Racing forged, 8,5:1 compression ratio custom made pieces, I had a problem with cracking ringlands on old pistons, by my fault running it lean, but it's fixed now, injectors were replaced by 33lb units from turbo 2.5, 255 lph higher flowing Walbro fuel pump was installed, and I recently replaced the intake manifold with a newer 3.3 manifold. The tranny was beefed up, pressure was upped on the valve body, Stratus main transfer gears were installed.
Timing and such (Jim Gathmann)
The coil pack has three coils. Each coil is for two cylinders, and the PCM (computer) sends one timing signal to each coil (so basically there are 3 timing signals- one for each coil). The reason for this is that the PCM gains better control over the cylinders. This way, for some reason, the PCM could have a different signal for each grouping of cylinders. But since these early PCM's lacked knock detector circuits, I fail to see what you'd want control over each pair of cylinders.
One could retard the timing by placing a timing controller unit on each of the 3 lines between the coil and PCM, but the cost of 3 timing controlers, at $150+ a piece, comes to about the same price as a complete DIS MSD ignition system!
