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GM Diesels.

Date: Thu, 19 Mar 1998 08:27:50 -0400 (EDT)
From: [email]
Subject: Re: New GM 350 diesel FS in NJ : $700

I hate to jump in but everything I've heard has been Bad with the gas 350 based diesel, no one I've met has had a good word for it, it seems it just wasn't up to the task, durable enough asa gas engine but not as a diesel... there are some pages on the net with people bitching about them and having specific complaints and analysis of their faults. I believe I've seen them under oldsmobile 98 pages and whatnot...

I've heard both good and bad about the 6.2 6.5 series as well, I believe they had trouble early on with headgaskets, I remember my fatherran a fleet of busses powered by them and you could not keep them, going. Also I've heard nothing but complaints from GIs who work with them, every one I know who has to work withthose GM diesels uses Navistars for their personal vehicles and won't touch the 6.2/6.5.

but then again didn't the 6.9/7.3 navistars have a bore erosion problem or something too?
matt

From: [email]
Date: Thu, 19 Mar 1998 07:29:46 -0600
Subject: Re: New GM 350 diesel FS in NJ : $700

I worked at a Chevy dealer during the hayday (if you can call it that) of this first generation of GM light duty diesels. It was one of the finest boat achors that GM ever built. I firmly believe that this engine did more to kill the market for passanger car/ light truck diesels than any other factor.

Date: Thu, 19 Mar 1998 08:48:50 -0500
From: [email] (Mike Smith)
Subject: Diesels

All, I have 2 mechanics working for me that are ex-US military. Both had to work on the Hummers with the 6.2 for the years they were in service, and both hate the GM diesels! 100's of horror stories. I know a lot of Rover owners are fascinated by this engine, most likely because you can by adpt. for it from the UK, but with all the really cool diesel engines, Cummings, Ford Power Stroke, some of the neat-o small Nissan and other Japanese turbo units I'd say you can surely do better with torque, mileage, durabilty, etc. One of our painters has a J**p M-715 with a Izusu turbo diesel from a large truck, that thing is cool. I also think that a small part of the interest in the UK with the 6.2 is its SIZE! For a UK powerplant that will fit in a Rover it is massive. Here in the US, my car has a 7.7 liter, so the 6.2 is no big deal. I'm sure some people love their 6.2, so please, no flames, this is just our opinion! Have a great day!
From: Mike Smith, EAST COAST ROVER CO.

Date: Thu, 19 Mar 1998 10:29:33 -0400 (EDT)
From: [email]
Subject: of 6.2/6.5 and 6.9/7.3ld.

Not that anyone cares, but the 7.3l Navistar engines seem to be quite impressive in extended use, I'd like to see a conversion using one of them!

Ive seen at least two with 280k before a rebuild was really even considered, and it seems as long as you use the correct coolant and maintain them properly they'll last forever. at least in big 40 passenger busses...

with the 6.2 and 6.5s there was MUCH more downtime, headgaskets were the main problem you couldn't keep them in them, there were other probs as well...

most of the Busses used to run on chevy 350s (gas) they recieved 2000 mile oilchanges for their whole lives and generally lasted 200k plus, the whole time toting ARC people throughout the county. it worked well as a gas engine goes.

now most buses come with BIG 6 cylinder turbo diesels, I thought about them for a conversion but they are MUCH MUCH MUCH too large, about a foot and a half higher than a Landcriuiser 6cyl engine.

Ive been mucking about with the idea of dropping a 7.3 into an M715 or something but I don't think they'd do in a landrover, who knows though, has anyone considered it? Id be interested in what other people have considered in the range of large diesels.(being american it seems I like everything bigger...) ;-)

thanks reply here or to my email if you don't want to clutter the list...
Matt

Date: Thu, 19 Mar 1998 07:46:16 -0800 (PST)
From: [email] (Jim Allen)
Subject: GM Diesels (Some LR content)

I may be in a postion to comment upon GM diesels, as I have had to immerse myself in them for the Four Wheeler project rig I'm building. Moderator, I believe this is relevant because a) there is plenty of precedent on this thread so far, and b) folks are installing them in LRs.

1) The early 350 Olds was anchor material. Nodootabootit! It got so bad that GM was actually doing gas engine conversions for customers under warranty (and threat of lawsuit) and there was a small sideline business for some shops converting the more unlucky owners whose engines lasted till they were out of warranty. As has been stated, it did more to kill the diesel market in NA than anything. If the engines listed for sale are these, they are a museum piece. Most of their ilk are holding down bouys at the yacht basin these days.

2) A second version of the 350 came out in the late '70s/early '80s that was OK. Also a 4.3L V6 version. I say OK, not great. They were definitely a light duty diesel powerplant, in the same category as the Volvo/BMW diesel, the VW, and some of the other Euro and Japanese diesel engines. The economy of a diesel but the longevity of a petrol.

3) For every 6.2L-6.5L horror story you tell me, I can come up with 10 extoling their virtues. People who work at dealerships/shops are not necessarily the best sources for info, because all they saw were the bum steers. The good ones were out there running happily and seldom seen (nobody goes back to the dealer for normal maintenance). I spent many years as a Land Rover tech. If you wanna hear some horror stories and base your entire outlook on them, I could put you off this list in an hour, completely cured of Land Rover. The only way to accurately plot good or bad is to compare sales records to shop records.

4) The 6.2-6.5 is what I would call a medium duty diesel. It falls short of some of the more industrial strength units, like the Cummins (I'm not sure the Navistar is quite in that category - I own one - but close), but it's easily capable of 250K miles, is lighter and easier to fit than either the Navistar or the Cummins and has fantastic economy. My stock'83 6.2L unit was delivering 24+ mpg and had 112K miles on it. The rig now runs 35 inch tires, weighs 6000 pounds and still delivers 20mpg at 75mph. It now has 140K and a recent compression and leakdown test yielded like-new specs. Anecdotal? Sure, but it is typical of the stories I turned up in a year of research.

5) I have also turned up some horror stories and a list of common defects. Acknowledged. A similar list can be made for any engine, including 2.25s, Rover V8s, and any other engine you care to name. The GM 6.2-6.5L diesel's list is no longer or more alarming than any other, and shorter than most. Like any engine that has been in production for a while, bugs get worked out and the engine improves with time. The newer verions are better, though I can't fault my '83 even though it was in the "troublsome era."

6) My reseach yielded some intersting statistics on diesels and their use with Americans used to gas engines.Some of this info indicates that light duty diesel failures are often maintenance problems. Diesels generally require less maintenance than petrol engines (excepting these new 100K petrol engines) but what they require, they DEMAND. Oil changes are one such item. The diesel soils it's oil faster than a gas engine and requires more freguent changes. The clarity and quality of fuel is also vital. Many Americans get into a diesel thinking they can run 200K miles with zero maintenance, then piss and moan when the injection pump fails at 60K miles because they never read their manual and never changed the fuel filters.

7) The general public's driving habits were one of the undoings of the 6.2. I won't go into much detail here, but a diesel likes a somewhat different driving style than a petrol. The ordinary "stoplight racer" American driving style is not the ideal diesel enviroment. Being normally aspirated and detuned, the 6.2s were fairly slow. That means that folks ran them wide open all the time. Since these engines were fitted to trucks, this was ususally under a load. No engine tolerates this for long, and diesels are even less tolerant. I think GM should have used the 155hp HD versions in the light duty rigs rather than the 135hp and the adoption of the turbo was too slow. Had the power output been higher, perhaps they would have been abused less. 'Course they would have been more highly stressed also. Perhaps a toss up.

8) Check out the 6.2-6.5 Diesel Page at [here].
Jim Allen