Chrysler, Dodge, and Plymouth 3.3 Liter V-6 Engines

large sections by Michael A. Cole

First used in a wide range of 1990 cars, the 3.3 was the first “clean-sheet” Chrysler-designed V6 engine, destined to become a workhorse for minivans — and, oddly, the basis of 255-horsepower Shelby Can Am cars.

3.3 liter V6

While traditionally designed in most regards, including the pushrod-actuated two-per-cylinder valves (rather than overhead cam with four valves per cylinder), it was the first production use of “beehive” valves, and had a distributorless ignition system (no mechanical distributor or rotor) from the start. The block was iron, the head was aluminum, and the valves were chain-driven. At launch, the fuel injection system was a simple multiple-port design; it went to sequential injection later.

The 3.3 engine was oversquare, for low-end torque early in the rpm range — just what was needed to power minivans and premium cars. That may also have been the reason for using just 12 valves, aside from cost.

The cylinder heads had alternating intake and exhaust valves, using large, symmetrical ports. 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 intake was a two-piece aluminum casting.

3.3 V6

A Hall Effect sensor on the transaxle bell housing and another on the engine front cover module sent out information about the crankshaft’s position and speed; the computer could figure out the injection/ignition sequence within a single crank for fast starting.

The early triple-coil setup fired two plugs at once, one to ignite the fuel, the other sparking during the exhaust cycle (so they wouldn’t need six coils). Spark plugs were gapped to 0.050 inches.

The 3.3 in production

The first production 3.3 liter V6 engine was made on May 1, 1989, in the Trenton, Michigan plant; at that time, it was used in the 1990 Chrysler Imperial, New Yorker Fifth Avenue and Landau, LeBaron GTS, and Town & Country. It also appeared in the Dodge Dynasty LE, Dodge Grand Caravan, and Plymouth Grand Voyager. When launched, there was no need for an air pump, aspirator, or EGR (except in California, where EGR was needed).

The 3.3 liter engine was fitted out for compressed natural gas when used in minivans, starting in 1994.

Five million (5,076,603) engines later, the last 3.3 was made at Trenton North (Michigan) on November 8, 2010; by then, it was only used in minivans. The 3.8 liter variant lasted until May 2011.

Chrysler launched a bored/stroked version (displacing 3.8 liters) for the 1991 Chrysler New Yorker, Chrysler Imperial, and Dodge Dynasty. It was extremely similar to the 3.3, and produced, in its first year, the same power but 15% more torque.

Marc and turbo 3.3

Engineers had a turbocharged 3.3 liter engine pushing out around 210-220 horsepower, 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]

Years bhp Torque
(lb-ft)
Notes
1990-1993 150 @ 4800 180 @ 3600 147 hp 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 wider torque curve.
2001-04 180 @ 5000 210 @ 4000 Variable intake, higher compression, new heads.
2005-10180 @ 5,200210-215 @ 5,000Changed to SAE measurement process

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
  • 4.0L Larger version of the 3.5 for Pacifica, minivans, Nitro

Common problems

For the most part, this engine series is very reliable.

Not starting

The starter 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,

3.5 liter V6"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.

  1. Remove the rocker shaft and the broken tower.
  2. Drill out any threads in the tower.
  3. 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.”

3.3 and 3.8 engines

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

A fuel rail recall was issued to cure 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.)

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 that this may be caused by rust build-up in the “donut” area of the exhaust manifold. Clean it with a metal brush, then coat the entire area with anti-seize before installing a new donut.

Other possible causes and solutions

Serpentine belt and tensioner replacement (separate page)

Performance

There aren’t many bolt-on performance upgrades for the 3.3/3.5/3.8 family. (See our article on 3.3-powered Shelby Can Am cars.)

Hank Heykoop wrote about removing the air cleaner restrictor, which can be done in tandem with upgrading the muffler, since the restrictor is there for noise control. “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. ... The restrictor is a cylindrical piece snapped into the input end of the actual airbox.”

Don Martin wrote a page on how to make a minivan-specific 3.3 performance air intake.

Nenad Sudar turbocharged his 3.3 liter Dodge Dynasty:

I replaced pistons with Ross Racing forged, 8,5:1 compression ratio custom made pieces. I had a problem with cracking ringlands on old pistons caused by running it lean; the injectors were replaced by 33-lb units from the turbo 2.5 and a Walbro fuel pump. I recently replaced the intake manifold with a newer 3.3 manifold.

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, the PCM could have a different signal for each grouping of cylinders. But since these early PCMs lacked knock detector circuits, I fail to see what you’d want control over each pair of cylinders [it’s possible the original plans called for knock sensors, which were eventually added].

The 3.3 liter V6 engine as adapted for Chrysler’s LH series

To use the 3.3-liter V-6 engine in the LH cars, they needed to convert it from the transverse “east-west” mounting to “north-south,” a 90° turn. Howard B. Padgham, head of powertrain engineering on the LH, wrote, “The block was altered only in respect to the attaching points. ... 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.”

3.3 liter chrysler engine in lh large car

“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.”

LH engineers also designed powerplant-bending struts between the block and transmission to provide more rigidity and stiffness, and used a three-point mounting system. In its first-year Dodge Intrepid use, the 3.3-liter engine delivered 153 horsepower at 5,300 rpm and 177 pound feet of torque at 2,800 rpm. It was used in the first and last years of the LH cars.

Technical details

In 1990, the intake valves were 45.5 mm (1.8 inches) in diameter; the exhaust, 37.5 mm (1.48 inches); both 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.

Valve guides and seat inserts were powdered metal; pistons were made of high-silicon cast aluminum, strutless to save weight, with a dished top, two compression rings, and a 3 mm three-piece oil control ring. The crank was also nodular iron, with 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.

EngineBoreStroke
3.393 mm 81 mm
3.596 mm 81 mm
3.896 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...).”

Unlike the 2.2/2.5 four-cylinders, the 3.3 is an “interference engine” — valve damage can occur if the drive chain breaks. That may be why the company used a chain, not a belt.

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?

3.3 liter Dodge V6

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.

The men behind the 3.3 liter V6 engine: Willem Weertman | Pete Hagenbuch

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