Chrysler, Dodge, and Plymouth 3.3 and 3.8 Liter V-6 Engines
Introduced for the 1990 model-year, the 3.3 was the first “clean-sheet” Chrysler-designed V6 engine. Used for decades, the 3.3 was a workhorse for minivans and a successful motor for racing (as used in 255-horsepower Shelby Can Am cars).
It was also the first production use of “beehive” valves, and had a unique distributorless ignition system.
The 3.3 had a cast-iron block, aluminum head, chain-driven overhead-valve design, and sequential, multiple-port fuel injection (SMPI); the distributorless ignition system dropped the mechanical distributor, rotor, and coil.
The 3.8 liter engine, launched in 1991 for the Chrysler New Yorker / Imperial and Dodge Dynasty (optional), was identical to the 3.3 except for the bore and stroke. It had different pistons and connecting rods, and a different upper intake manifold and crankshaft (the valves were the same). In its first year, the 3.8 produced 150 horsepower at 4,400 rpm — the same as the 3.3 and about the same as the 2.2 Turbo I — and 204 lb-ft @ 3,200, around 15% higher than the 3.3 (112 kW and 277 Nm).
The 3.3 spawned an 3.5L aluminum-block, 24-valve engine designed for the new LH platform. It was later joined by an all-aluminum 24-valve 3.2L V6 featuring a unique (at the time) coil-over-plug design.
Engineers had a turbocharged 3.3 liter engine pushing out around 210-220 horsepower on tap, to fill in for the 3.5 liter while it was being developed; an executive squashed the project. It would have given Chrysler a higher-power V6 two years before the 3.5 was ready. [Marc Rozman on testing the turbo 3.3]
With torque coming early in the rpm range, the 3.3/3.8L series was well suited to powering for minivans and large cars such as the Fifth Avenue and Imperial. The engines survived for two decades with an unblemished record of quality and service.
The 3.3 liter V6 engine was first made on May 1, 1989. Five million (5,076,603) engines later, the last 3.3 was made at Trenton North (Michigan) on November 8, 2010. A new 3.3 liter engine based on the Pentastar V6 was being piloted even as the original was wound down (it was never made, though).
The 3.3 engine had an oversquare arrangement, providing for low-end torque and large valves; the cylinder heads had alternating intake and exhaust valves, using large, symmetrical ports, two valves per cylinder, with a pushrod design. There were two squish areas, around a third of the bore area, at launch. It started out with multiple point fuel injection and a self adjusting serpentine belt. The intakewas a two-piece aluminum casting.
The distributorless ignition used a sensor on the transaxle bell housing which determined crankshaft position and speed, based on twelve sensing slots; and one on the crankshaft on the engine front cover module, with slots coded for each cylinder. The computer could figure out the injection/ignition sequence within a single crank for fast starting. Both sensors were Hall Effect types.
The triple-coil setup provided 20% more energy than past Chrysler single-coil systems, and operated two plugs at once, one to ignite the fuel, and the other harmlessly during the exhaust cycle. Spark plugs were gapped to 0.050 inches. When launched, there was no need for an air pump, aspirator, or EGR (except in California, where EGR was needed).
3.3/3.8L Engine Chronology
In 2010, the 3.3/3.8 were the only remaining Iaccoca-era power plants still seeing active duty, outlasting the AMC straight-six and Chrysler’s LA V8 engines.
|1990-1993||150 @ 4800||180 @ 3600||147 hp version was used in Dynasty and New Yorker.|
|1994-1995||162 @ 4800||194 @ 3600||Revised intake plenum.|
|1996-2000||158 @ 4850||203 @ 3250||Revised intake and exhaust for enhanced torque.
Lower horsepower but torque increased and peaked earlier.
|2001-04||180 @ 5000||210 @ 4000||Variable intake, higher compression, new heads.|
|2005-10||180 @ 5,200||210 to 215 @ 5,000||Change SAE standard measurement: same numbers, higher revs|
|1991-1993||150 @ 4400||213 @ 3600||Used in New Yorker and Imperial; optional on Dynasty.|
|1994-1995||162 @ 4400||213 @ 3600||Power increase for 1994 via revised intake plenum. |
In minivans now – never again to be used in cars.
|1996-1997||166 @ 4300||227 @ 3100||Revised intake and exhaust systems to boost power and torque.|
|1998-2000||180 @ 4300||240 @ 3100||Boosted power and torque.|
|2001-2007||215 @ 5000||245 @ 4000||Variable intake, higher compression, new heads.|
|2008-10||200||245 @ 4,000||No explanation for power drop|
|2007-11||205 @ 5,200 |
|240 @ 4,000 |
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 3.3 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 (at the cars’ launch).
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 and never had 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.
At launch, the intake valves were 45.5 mm (1.8 inches) in diameter; the exhaust, 37.5 mm (1.48 inches). Valves were actuated with roller tappets from a hardened nodular iron camshaft. The drive chain was 3/4 inch wide. The conical-shaped “beehive” valve spring appears to be the first use of this design, later claimed by Mercedes. A spring tappet anti-rotation mechanism was used. Valve guides and seat inserts were powdered metal. Pistons were made of high-silicon cast aluminum, strutless to save weight, wtih a dished top and two compression rings and a 3 mm three-piece oil control ring. The crank was also nodular iron, wtih four main bearings and cross-drilled main journals and rolled fillets.
The front cover module had a cam drive-chain housing, oil pump, water pump housing, front crank seal retainer, and accessory drive mounting. Cylinder covers were stamped, laminated acoustic steel with a molded rubber single-plane gasket including a backbone and metal compression limiters. The heads were cast aluminum, with a machined cover rail for better sealing.
|3.3||93 mm||81 mm|
|3.5||96 mm||81 mm|
|3.8||96 mm||86.9 mm|
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. ... 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...).”
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.
The 3.3 is an “interference engine” — valve damage can occur if the drive chain breaks.
The “K” and “LH” V6 families
Bob Sheaves 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
For the most part, this engine series is very reliable. See the introductory part for some issues.
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 Mastriano 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 procedure 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."
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 (replacement 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."
“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.”
Serpentine belt and tensioner
Serpentine belt and tensioner replacement (separate page)
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 controllers, at $150+ a piece, comes to about the same price as a complete DIS MSD ignition system!