Mopar 2.2 Liter and 2.5 Liter Turbo Engines: Common Repairs and Performance Upgrades
Note: we are not responsible for the veracity of any information on this page or the results of any attempts to use it. Increased performance often occurs at the cost of the longevity of the engine or other car systems, e.g. axles, transmissions, suspensions. Brake and steering system upgrades may be wise when power is increased.
John Nelson wrote:
One feature not yet mentioned on the 2.2 page is the ease and accessibility of servicing these engines. The Factory Service Manual is a valuable resource. Routine maintenance couldn't be easier, the plugs, air box, and distributor are almost in your lap! Pulling the head for head gasket service can be accomplished without removing the manifolds (the procedure is not in the manual) and doing the timing belt is a relatively easy four hour job. My 1988 has over 190,000 miles on it, and I recently found that the timing belt tensioner pulley can wear in a way that allows the belt to slip over the rim of the pulley and eat itself up... (The manual did not have a step recommending to check for that.)
On the Turbo I, the wastegate tends to stick open. You can fix this by removing the wastegate, and installing a new one. Another problem is the Torx bolts that attach the crankshaft pulley. You can save yourself the time and money of buying a Torx set of sockets, and just cut about an inch off of the lower protective cover below the belt. Don't try removing it, you must remove the front main oil seals to do so and it's not worth it.
The 2.2L Turbos idle very hot, reaching in excess of 200 degrees. The idle is high and rough. True, they were designed to run higher than other fours, but it's crucial that you keep your timing accurate.
All in all, the 2.2L four is a great engine, and all it really needs is attention, and a little innovative thinking to get around those pesky problems.
Jeremy Zumwalt wrote: I went through more than a half dozen constant velocity joints (CV joints) between my 1989 Daytona C/S and my 1987 Lebaron before a mechanic hit on a fix. Change the motor mounts. The engine torques the mounts so much it bends them putting pressure on the C/Vs and breaking them. After breaking them at a rate of one every 4-6 months I went 15 months without before I sold my car.
David Reynolds wrote: There are three common causes of the [clacking] noise: wrist pins, piston slap, and valve train noise. It seems possible that T2s, with floating wrist pins, might suffer less than the others from wrist pin noise.
Jeff Chojnacki wrote: Stock pistons/wrist pins are famous for making the clacking sound. My Shelby Z has over 143K miles on it and has been making the clacking sound for some time now. However it is not as loud as I've heard in many T1s. Fortunately, a motor can run with the clacking for a long long time without damage. Not like a rod knock or detonation.
Wes Grueninger said: Almost all radiators used with nonintercooled 2.2s, carbed, TBI, or T1, are identical in dimension, regardless of body style. They have a 22-1/4"x15-1/4"x1-1/4" 2-row core, 1-7/8x16-3/8 end tanks, a 1 to 1-1/4" inlet and a 1-1/4" to 1-1/2" outlet. This applies to 1981-89 models. N bodies, P bodies, and Dakotas use different radiators.
Disintegration of the vacuum hoses
Over time, the vacuum hoses may disintegrate where they go over the engine. The solution is to replace them, as you might expect. One set goes to the vapor canister; this set includes two vacuum check valves. Twin vacuum hoses come from the throttle body, meet, and join before running to the vapor canister relay. Another hose goes from the wastegate to the turbo solenoid which is right next to the vapor canister relay. You can't get the solid pipes used by Chrysler any more, so use ordinary vacuum hose (for the vapor canister line, you need to use fuel line hose) with standard connectors. Make sure you re-create any orifices (glue and a drill bit?).
Tim Mikolay wrote: I retorque the spark plugs and the throttle body gasket bolts at every season change. They work themselves loose. With a new (1990s) one piece valve cover gasket, a redesigned oil filler cap that doesn't leak and hose clamps on either end of the hose connecting the valve cover to the air filter housing (legendary for oil leakage), oil stays.
2.2 engine power bands (by Jeff Chojnacki)
The cam/porting/restrictions is still what basically defines the power band on a turbo motor. Although when you raise the boost it feels like it pulls sooner and higher, however this is because the motor is making more power, the curve has about the same shape. A 2.5L turbo is still thought of as a low end motor while the 2.2L turbo is a higher rpm engine relatively ). ex. Gus just got his FM Stage II converter for his 2.5L that's got a stall set at 3000+ rpm. The stage II converter I ordered for my 2.2L is set at 4000+ rpm. We will both leave the line close to our torque peaks.
In general the '84-'87 2.2 T1s breaths well up to 5700-5800 and a '88+ T2 is around 5500. The difference is in the cam. The FM 475 cam allowed my T1 to breath up to 6000 ok. That same cam in my T2 w/ porting will breath up to 6300rpm, but doesn't start making real power until 3200 rpm.
Turbo I to Turbo II conversion
One of the most popular ways to increase power for the Turbo I is to convert it, at least partially, to a Turbo II. Jeff Chojnacki wrote: "These pieces are not just bolt ons, you may want to consider doing most of the conversion at once. How many times do you want to take the motor apart?...You can drop in a T2 bottom end w/ head and attach all the regular T1 stuff to it and it will run great. Or you may even rebuild your T1 block w/ head and attach the T2 intake/exhaust/turbo/TB/computer. An '87 bottom end is still pretty strong!
After that, it's best to do both manifolds, turbo, TB, and computer at the same time. The T1 turbo hardly clears the T2 intake and the 4 - wire AIS sometimes works with '87 T1 logic modules. I'd recommend finding a T2 intake and exhaust manifold and a T2 turbo. A dead T2 turbo will work too.
[A same-year] logic module will drop right in - but you have to run two extra wires to the AIS motor and extend the Intake Charge temp sensor wires. Neither of which are that difficult. Don't run the T1 injectors with the T2 computer.
Vacuum wiring is the next fun step. On my Lebaron I made it up as I went along. :) It helps to get some of the major T2 pieces ( elbows, molded lines, etc ). That 4 way connector from your T1 works in the T2. I believe that the T1 oil feed line requires some bending to fit around all the T2 parts.
Less involved performance boosts
Chuck Green wrote:
- Power flush the fuel injectors and fuel rails and change the fuel filter
- Power flush the transmission fluid out on a machine and then change the filter and install all new fluid [Editor's note: 7176!]
- Flush the radiator out and install new thermostat (190 degree) with new gasket and coolant
- Clean out the Throttle Body of all carbon [Editor's note: can be very important!]
- Change the Spark Plugs to Champion (gap to .035)
- Change the Air Filter element to a K & N Unit
After all this is done I would do the following
- Cut off the original exhaust and install a 2.5" diameter exhaust with a Walker Dynomax Muffler and a performance CatCo Convertor
- Install a set of Taylor spark Plug Wires
- Wire Seperators for the plug wires
- Also buy and install a Mopar Performance Computer (this is available from Forward Motion.com)...
Boost adjustments and Grainger valves
The late Gus Mahon (owner of the 12 second minivan) and others pioneered and popularized the practice of getting more power from the 2.2 and 2.5 liter turbocharged engines by adjusting turbocharger boost levels (presumably at a cost in engine life, though the 2.2 seems fairly durable despite such boost boosting). For example, Paul Kraus wrote:
Under boost conditions (when the turbocharger is active), your vacuum lines turn into pressure lines. The pressure acts upon the diaphragm inside the small round can (waste gate actuator), overcoming the internal spring inside, and pushing the wastegate open.
If you tap into the direct hose from the manifold to the waste gate controller, it allows full boost to the controller. Depending on the spring you have, and how tight it is, it should open the waste gate around 5 to 7 psi. Shorten the rod, or put washers under the can to further compress the spring, and this value will increase. This is minimum boost. To run less boost than this will require mechanical modifications to your waste gate.
If you completely disconnect the manifold source of pressure, the internal spring will keep the wastegate closed until exhaust back pressure simply becomes too great, and pushes past the actual wastegate, overcoming the spring. This amount varies widely. On Mitsu turbos, about 17 psi, on Garrets, normally above 20 psi, but some came with weak actuator springs, and will be lower, like around 15 psi I think. My Enforcer turbo is about 25 psi (where I run it!)
To control boost at some point between minimum and maximum, you must provide a regulator pressure source to the actuator. Factory cars do this with a solenoid valve, which is cycled very fast by the computer, allow a controlled amount of pressure to reach the waste gate. The MAP sensor is used by the computer to measure the pressure.
The Grainger valve, used be me and hundreds of others to control boost, is nothing more than a pressure "pop off" valve used on industrial air compressors. It is a steel ball, held against a sealing seat by a spring. Pressure is applied to the inlet of the valve, and when enough pressure is present, it overcomes the spring and allow air pressure to pass through the valve. When connected to the waste gate, this spring pressure can be set to "pop off" at the boost pressure you desire. When boost set point is reached, air pressure flows through the "G" valve to the waste gate and it opens. easy boost control. Tighten the spring in the G valve and boost setting goes up!
Other 2.2 turbo engine performance issues
See our interview with engine tuner Mike Holler, who details a cost-effective 2.2 turbo buildup.
Maurice Barrett wrote: "The only thing that really holds most of the 2.2/2.5s back is the 8 valve SOHC design, which is why a lot of turbo Dodge people run high boost levels. While this is a disadvantage for many there are also the TIII 2.2 DOHC 16v Turbos which have a Lotus designed cylinder head and the Masarati 2.2 16v. Unfortunately these are harder to find and parts are expensive. The other alternative is mating the Neon DOHC head to the 2.2/2.5 block, which has been done by a few people already. No matter which way you go though you are still using Mopar parts which is kind of interesting and unique.
"But what really makes turbo Dodges so much faster than other turbo cars is that we are the underdogs or often overlooked. It seems to me that most people don't realize how fast these cars can be made and how cheap they can be had. Generally speaking your average Joe in the Mustang, or Camaro, or Integra, or whatever isn't going to realize what hit them until after its over, and even then they don't want to acknowledge the facts. If you didn't know much about cars, would you be more intimidated by a Spirit R/T, or a Talon TSi?"
Other 2.5 / 2.2 turbocharged engine performance and repair sources
We have a small page on turbo bleeds - an inexpensive way to greatly enhance the power of the turbocharger. In addition, for those troubleshooting their systems, we have a page on turbo boost spiking and boost creep. Meanwhile, acarplace has an interview with a Garrett turbocharger engineer.
FWD Performance has products for the 2.2 and 2.5 engines, including modified computers. David Lucidi recommended James Richardson, and his company, Turbo Star Racing, for turbo modifications and fuel pressure regulators.
See 13 Seconds Next! How to build a Mustang-stomping Chrysler Turbo 4 (by Tom Hand)
Advancing cam timing tends to increase both economy and gas mileage.
There's a wealth of information at Gus Mahon's site.
A site of interest (thanks, Stephen Lyons) is http://www.thedodgegarage.com/turbo_intercooling.html, which discusses intercooling.