2.1 Turbo Diesel Knowledge

Any one at all have any knowledge of the 2.1 Turbo Diesel 85 Cherokees? I am looking at one. It is rebuilt but over revs after warmed up. I'm thinking oil leak from turbo or plugged oil return on turbo? Bad head gasket sucking oil, but I'd think it would build up coolant pressure before oil in the cylinders?? Air sensor???Help!

I have an '86 Comanche with the 2.1L. The first thing I would check is that the thermostatic capsule on the injection pump is working properly. It sets cold idle and timing, and should relax when warmed up.

Thermostatic capsule:



What exactly do you mean my 'over revs' though?

Rob

Drove one of those in college had a spare alternator and starter that were expensive to rebuild. Great mileage- sucked on power.

Depending on the 2.1, you can have 2 systems, one being a Delco starter/alt, and the other being a Paris-Rhone. I have the Paris-Rhone, but you can get replacement alternators still. Carquest found me one on a shelf in New York or Jersey... Can't remember which now.



The starters are known for cracking the aluminum bell housing because of the torque. When I found my MJ, someone had already repaired a crack.

Rob

automan2164 said:

I have an '86 Comanche with the 2.1L. The first thing I would check is that the thermostatic capsule on the injection pump is working properly. It sets cold idle and timing, and should relax when warmed up.
Thermostatic capsule:
What exactly do you mean my 'over revs' though?

Rob

Click to expand...

I don't know the symptoms but what I was told it increases it's rpm's. I'm thinking it may be getting oil in the intake from a leaky turbo or glogged oil return line turning the oil into fuel. I could not get it started. I think the factory in tank fuel pump quit. No fuel out of the steel line. I cracked the injectors nothing pulled fuel line nothing. So I'll go back next week and bring some fuel in a tank and pump directly to the injection pump and see if she fires. Tell me a little more about the thermostatic capsule?

The head gasket was replaced again after the motor was rebuilt because there was some debris that stuck to the gasket (I'm thinking head or block not cleaned correctly). The head went thru all 4 torque down specs. The injection pump was rebuilt also at the same time! Radiator recored ect... Any other pointers you guys can give me I'd appreciate it!! Oh brand new alternator too. Not related: 5 New tires! The floor is rusted thru on the driver side and not too bad on pass. Missing the back hatch inside cover (I have one in the same color), the interior is suprisingly clean! I don't know whether to take a chance on it or not. Seller wanted 1700 I offered 1200 before the no fire, then I offered 500 and thought I'd take a chance? What do you guys think

The thermostatic capsule is a temperature sensitive actuator that pushes/pulls on the cold start/base timing lever. It is coolant fed, and designed to hold the idle up until warm, as well as alter timing to assist in warming up. I replaced mine because I had some issues when I first picked mine up.



A factory XJ/MJ diesel doesn't have an in tank pump. The only pump is a vane style lift pump built into the injection pump, and I believe there may be one in the fuel filter housing on the firewall. I just rechecked my parts book and my Renault injection book to confirm.

I would be real worried about the rebuild. There are different size head gaskets based on what was required to meet the deck height and combustion chamber needs when it was assembled. Many people don't know this, and they slap in whatever gasket they get their hands on. It could lead to problems. I would especially be worried about them saying they had to redo it because of "Debris" on the surface/gasket. If you miss a crucial step like maintaining a clean area or proper prep of your job, you probably shouldn't be in there.

The engine is an interference engine, and if timing isn't just so, pistons can kiss the valves also... Leading to a bigger mess. They should have also replaced the timing belt along with all that work.

Questions I would ask of them:

Why was it rebuilt?
Where was it done?
Competent shop?
Warranty?
What was replaced?

The Renault is tricky. If it wasn't taken care of, it's going to be nothing but problems or a money pit. Aluminum head, block, easily warped... All it takes is one person under there that doesn't know what they are doing to mess up the works.

If it's already not running, I wouldn't treat it as anything but. Unless they realize that they are selling a non running vehicle that is uber hard to find parts for and price it as such, I would move on. Keep in mind that the only things to get the 2.1L Renault in the states were the few years of XJ/MJ and the Winnebago Lesharo motorhome which stopped production at about the same time. Parts, when you can find them, are expensive.

Rob

Thanks for all the info! Yes I was aware of the 3 head gasket sizes and the 4 torque specs on the head. They don't know why it was rebuilt but it came with a spare 2.1. He said it ran but had probs with the water building pressure from the bad or wrongfully installed head gasket. They fixed it and then the runaway engine happened. I offered $500.00. mainly for the smogless diesel tittle. I have a V8 1985 Chke Chief that I built back in 90's that has all Bronco running gear with a built Boss motor that I was going to upgrade to one tons or military's under,o r possibly put a 4 or 6bt in it and run it, that is why I wanted it to register legally, per say. They haven't called back on my offer so I guess I"m out!

Happy to share the info with whomever I can. There isn't much of it out there. The more and more info I get out onto the interwebs... More searchable returns for anyone interested.

I would be worried seeing as they know little about what they have... If somehow you do end up with it, and want it for a smogless title, I would be interested in any of the diesel stuff you do away with.

Good luck!
Rob

Didn't get it. I was too busy at work to mess with it but the guy had a spare motor. If I find his # I'll pass it on. There is a wrecking yard back east that contacted me after I Googled info that had a complete running motor with warranty at $1400.00 including shipping!

1400 for one of these motors is dirt cheap.... A head with no can, valves, injectors, rockers, etc. retails at over that.