Turbo 2.1 Diesel Comanche, Help!!

[azdiesel]

Just bought 86 Comanche diesel 2.1 and could use some help.

 

1)  Could use any technical publiations with details on motor.Already have factory shop manual which isn't very complete.

2)  Have oil in radiator. Where is it coming from? is this a common problem?

3) Where is vacuum reservior?

4) Details on vacuum lines as all of mine were disconnected.

5) Would like to hear another one run as a comparison.I live in Phoenix,AZ

6) Will probably pull the engine due to many oil leaks. front & rear crank seals.

7) Had diesel mechanic drive it. He stated it ran quite well but smoked quite a lot.

8) Injectorer were bench checked and found to have bad nozzles---being rebuilt.

9) Major concern at this time is oil in water. No water in oil, truck doesn't use water, doesn't over heat or show sighns of a bad head gasket.

10) Is cooling system on this engine prone to cavitation causing possible oil in water?

 

Any help, conference phone calls or any other communications would be appreciated.

 

Richard in Phoenix

[jimoshel]

Sounds like to me you just got yourself a truckload of head aches. I would suggest you find some dumb fish and pawn it off on him.  Should be somebody around dumb enough to want it. I'm PM'ing you my PN. :yes:

[azdiesel]

Sounds like you are not a diesel Comanche fan! Have you ever driven one or for that matter seen one?  Some say that only a diesel is a real truck, all others are wannabees. For sure, this will be an education---parlevue frenchie or something like that. So far, the Comanche is just the right size for me as I just sold my Dodge Ram 2500 Diesel. Years ago, i bought a 66 dodge  with a 426 street hemi. it took over a year to figure that one out. the front licence plate said excedrin headache # 426. This was telling me something!!  Nothing could be as bad as that one was! Best it ever did was 11mpg with a quart of 50w oil every tank of gas.

 

Your reply is appreciated. Thanks

[dasbulliwagen]

There are a couple of MJ diesel gurus on here. Just give them a little time tio chime in and youll be all set!

[rmoore1031]

I know nothing about the 2.1 but I'm jealous that you have one. I haven't found any in NY.

[87manche1]

Fyi jims just jealous he's looking for a diesel alternative.

[jimoshel]

Fyi jims just jealous he's looking for a diesel alternative.

YEP! Some peeps just don't recognize tongue in cheek humor. :rotf:

Oh. And that's 'Parlez vous Francais'  Do you speak French?

[azdiesel]

No speka da francheze,  un pokode italiano & Espinolski

[Alexia]

Any technical answers from me are just general answers as I do not direct experience with this motor.

1)  Could use any technical publiations with details on motor.Already have factory shop manual which isn't very complete.

There is a diesel manual supplement floating around the internet somewhere. I am still trying to find it.
Rob(Automan2164) may be able to send you some details. He also has a thread on his diesel truck with many pictures from doing engine tune ups.
http://comancheclub.com/topic/31030-diesel-fuel-only-factory-diesel-comanche/

2)  Have oil in radiator. Where is it coming from? is this a common problem?

Option A.)
The radiator includes an oil cooler for the transmission. The radiator may have fail and is allowing the fluids to mix. This means replacing the radiator, flushing the oil and coolant, and refilling.

 

Option B.) The "OH NO" option.
Oil in the radiator can mean a blown head gasket. Another way to verify this is if the oil on the dip stick is milky.

3) Where is vacuum reservior?

 

On 4.0L models it is attached to the back of the bumper on the right side.  Just a round plastic ball.

5) Would like to hear another one run as a comparison.I live in Phoenix,AZ

 

From Rob.

 

 

[92tanMJ]

So jealous man, I know nothing about diesels but I would love to swap one into mine

[jimoshel]

Interesting tidbit. For people who like tidbits. At the end end of WII when the B29 finally got into action, they used multi fuel engines. Used 100 octane Av for take off and climbing to altitude. After reaching their altitude they would switch to diesel for cruising.

[HOrnbrod]

Opsled, a member here, had an MJ diesel for years and is very knowledgeable regarding these creatures. Hopefully he will chime in.

[azdiesel]

Vacuum reservior is not in front behind bumper. the 2.1 diesel is different!  My Comanche is a 5speed manual, No cooler lines of any kind in the radiator.  as of this afternoon, smells to be diesel fuel in the water---blown headgasket?  No water in oil nor does it use water!  ( and it runs great, no sign of blown head gasket. so, it's coming apart because of oil leaks. Engine oil cooler is oil to air mounted just behind the grill next to intercooler.

[mvusse]

I thought diesel engines didn't produce any vacuum to speak of, so it should not have a vacuum system. Now I have never seen a Renault 2.1 in a Comanche or Cherokee, but every diesel I have looked under the hood ( granted, only a few) used hydroboost brakes because of this.

 

Hope you will never need parts for the engine. Even in Europe parts have been discontinued for years and are impossible to find.

[jimoshel]

I thought diesel engines didn't produce any vacuum to speak of, so it should not have a vacuum system. Now I have never seen a Renault 2.1 in a Comanche or Cherokee, but every diesel I have looked under the hood ( granted, only a few) used hydroboost brakes because of this.

 

Hope you will never need parts for the engine. Even in Europe parts have been discontinued for years and are impossible to find.

They don't. That's why most, all?, of the big rigs have engine driven vacuum pumps.

[terrawombat]

Most diesel engines will not create any measurable vacuum like a gasser.  There are a couple of diesel engines out there that will create vacuum with a throttle plate, but they're mostly used on forklifts.

[Zebvance]

I don't get it. Then Benz engines are great. But have now power at all. My roommate has a 80 300sd. Slow as balls. Can barely break the tires loose on dirt. Numbers on this motor a equally not impressive and far as power is concerned.

[johnj92131]

The M-B diesel has a lot of potential power.  More important, it has torque, and it is fantastically reliable.  Parts can be had all over the place. 

I don't get it. Then Benz engines are great. But have now power at all. My roommate has a 80 300sd. Slow as balls. Can barely break the tires loose on dirt. Numbers on this motor a equally not impressive and far as power is concerned.

[terrawombat]

I don't get it. Then Benz engines are great. But have now power at all. My roommate has a 80 300sd. Slow as balls. Can barely break the tires loose on dirt. Numbers on this motor a equally not impressive and far as power is concerned.

What is it that you don't get?

[cruiser54]

 

I thought diesel engines didn't produce any vacuum to speak of, so it should not have a vacuum system. Now I have never seen a Renault 2.1 in a Comanche or Cherokee, but every diesel I have looked under the hood ( granted, only a few) used hydroboost brakes because of this.

 

Hope you will never need parts for the engine. Even in Europe parts have been discontinued for years and are impossible to find.

They don't. That's why most, all?, of the big rigs have engine driven vacuum pumps.

Big rigs don't have vacuum pumps. Mostly passenger vehicles do. Big rigs use air pressure operated accessories rather than vacuum as they are equipped with air brakes already.

 

[azdiesel]

Interesting comments-----

 

1) a turbo comanche needs vacuum to operate the power brakes, heater/a/c  controls & cruise control. They have two seperate vacuum reserviors, one is just for cruise control---according to the factory manual. BUT---they are not located in the same place as the gasoline powered vehicles & the shop manual does not tell where they are! The 2.1 renault has a diaphram vacuum pump on the engine. Same manufacturer as a MB 240 or 300D. The diesel also uses vacuum to control fuel mixture based on atmospheric pressure & possibly temperature.

 

regarding parts, there is a new short block and head on ebay for $160.00.   Unfortunately, it is pickup only, no shipping & it's in England. Parts are hard to find & you have to be patient .  I have driven a few 300 sd turbo Mercedes and was quite surprized at how fast they were!  I would say that a 300mb turbo diesel in cherokee would out perform a 4.0 gas engine hands down. With a few mods, It would start breaking driveline components/transmissions. 250 to 300 hp would be relativly easy to come by not to mention gobs of torque.

 

The newer VWs use an electric vacuum pump operated by the ecu. I was going to install one until I found the rebuild kit for my oem vacuum pump.

[JeepcoMJ]

Just bought 86 Comanche diesel 2.1 and could use some help.

 

1)  Could use any technical publiations with details on motor.Already have factory shop manual which isn't very complete.

2)  Have oil in radiator. Where is it coming from? is this a common problem?

3) Where is vacuum reservior?

4) Details on vacuum lines as all of mine were disconnected.

5) Would like to hear another one run as a comparison.I live in Phoenix,AZ

6) Will probably pull the engine due to many oil leaks. front & rear crank seals.

7) Had diesel mechanic drive it. He stated it ran quite well but smoked quite a lot.

8) Injectorer were bench checked and found to have bad nozzles---being rebuilt.

9) Major concern at this time is oil in water. No water in oil, truck doesn't use water, doesn't over heat or show sighns of a bad head gasket.

10) Is cooling system on this engine prone to cavitation causing possible oil in water?

 

Any help, conference phone calls or any other communications would be appreciated.

 

Richard in Phoenix

Opsled is my father, and I learned to drive on his diesel MJ.

 

Oil in radiator indicates to me that there is a crack in the head or something of that nature. This is not unheard of, though I have no direct experience with oil in coolant.

 

Ours drove for 100,000 miles with a crack in the cylinder 3 behind the precup, putting pressure into the cooling system. We could not get the boost above 5PSI or we would end up losing coolant as well as heat. You could have a similar issue, as well as blow-by in the cylinders, thus putting oil into the cooling system. This is a reasonable solution considering how much the jeep allegedly smokes.

 

In no way have I ever heard of cooling system cavitation causing oil in coolant.

 

As the charge cooler is seperate, located on the passenger side of the engine bay, and in no way attached to the radiator, you cannot be confusing the two.

 

Vacuum reservoir is on both sides of the bumper, behind it near the end caps.

 

I cannot help you with vacuum diagrams. Let's get Rob to snap pics of his.

 

2.1 TD and non-turbo have a vacuum pump located on the driver's side of the motor underneath the injector pump. It's likely blown, and IIRC Rob found a source for them.

 

There are two different styles of alternators. One is a GM style, the other is a Paris Rhone. The latter is the harder to find, although I believe Rob found a source for them through carquest.

[azdiesel]

Thanks for the feedback. I understand the intercooler and oil cooler. Someone else mentioned a connection of the radiator having oil cooling coils internally. You are correct in that there is no direct way for the oil to enter the cooling system except as you mentioned, a cracked head/ leaking head gasket or the like. There is a poduct that claims it will seal up this kind of crack leak. I might give it a try and remain quite sceptical especially with a diesel. it has been establishe that the oil is diesel fuel. it doesn't use water overheat here in Phoenix and it runs great. So, time will tell.

 

I learned of a 7.3 ford that ate through a cylinder liner due to cavitation which accelerates the process when the coolant has an unhealthy ph level. I was informed that cavitation in diesel cooling systems is common due to the high frequency flexing of the block due to operational stresses. I am familiar with cavitation but in a diesel engine block is new to me. There is an rpm on the older Lamborghini engines where the block starts vibrating (ringing) as the natural resonant frquency of the block is passed. I suspect many engines experience something like this.

 

By the way, My tach was inop and found the rectifier plate in the Paris Rhone alt to be bad. Found the parts locally after 2hrs on the phone.

[JeepcoMJ]

that's not going to happen in a renault 2.1.

 

The cylinders are drop-in sleeves in an aluminum block that are the better part of 5/8" thick.