When you say the words “GM diesel” in the context of a vehicle from the 1980s, I wouldn’t blame you for thinking the worst. After all, GM had a significant swing and miss when it came to selling a diesel-powered sedan in the U.S. with the Oldsmobile V8 under the hood. These engines were trouble-prone and often not worth the cost of admission. However, a lesser-known engine and certainly seen quite rarely is the 4.3L diesel V6 that came in cars like this minty 1984 Pontiac 6000. The six-cylinder version fixed a number of issues with the earlier motor, but sadly seems to live in its shadow. Find the diesel Pontiac listed here on Facebook Marketplace for $6,500.
I often wonder with cars like these how many are truly still on the road. One would think it has to be nearing double digits – like, literally 50 cars still driving with registered plates on them. I haven’t seen a 6000 outside of a junkyard (and even there they’re a sight) in probably 10 years. I always loved the STE versions, especially the later cars that combined AWD with the racy appearance package. At one time, automotive pundits thought the 6000 could be a world-beater for Pontiac, putting it on the stage with the world’s best sport sedans. Obviously, that never happened, but it’s interesting to think about a brand like Pontiac being allowed to continue refining a decent platform – what could it have become?
Back to the matter at hand: the 4.3L V6 diesel introduced a number of “fixes” for the shortcomings of the V8. A water separator and fuel filter in the V6 helped prevent the issues in the V8 caused by water entering the fuel mixture which, of course, ruined injection pumps and injectors, both of which were costly and annoying fixes. In addition, head bolts were the other major issue. While the material of the bolts themselves was suspect, the bigger issue was too few of them. The V6 addressed this by adding six bolts per cylinder, an increase over the V8’s four per cylinder design. Another fun fact is that the diesel used in front-wheel drive applications was the extensive use of aluminum, and as such, significant weight savings were achieved over rear-wheel drive diesel applications.
The shame of it is that even today, the flaws of GM’s diesel overshadow its efforts to mass-produce a fuel-efficient vehicle with good power. But the flaws themselves were not egregious, in my opinion – sloppy, yes, but GM’s engineers were quick to make the necessary fixes. Unfortunately, the impact of the media and consumer sentiment are two influences that make it very hard to reverse course. Regardless, this honey of a Pontiac 6000 looks like it has years of life left in its wheels and the interesting engine choice makes it an enthusiast darling despite not being particularly beautiful or fast. The asking price may have to dip below $5,000 for it to find a new home, in my opinion. Thanks to Barn Finds reader Sam61 for the find.
A “good” GM diesel from the ‘80’s-almost a oxymoron but the two V6 GM diesels (not sure what ci they were) in our neighborhood just seem to run for decades then disappeared some years after the owners quit driving.
GM–Oldsmobile–diesels got a real bum rap right out of the chute. They got launched into a field full of gas-pot mechanics who started blaming the LAST thing that should be blamed: the injection system.
Face it, whenever the engine acted up they blamed the ONE they knew nothing about. And they were WRONG almost 100% of the time.
Diesels played right into my hands. I was a diesel mechanic while I was a gaspot mechanic. I’d been around both long enough to know what made each one tick, so I knew what to look for when diagnosing a problem. Needless to say, our dealership had some problems with diesel but nothing close to what other dealerships had.
When the V-6 units came out most of the diesel problems were cleared up but there were some that carried over, mostly due to the mindset developed when the V-8s were at the forefront. But still the bad press generated by that mindset helped to kill an otherwise good engine.
Personally, I wouldn’t turn an Olds based diesel engine down if I was in the market. I’d like to find an ’80-’82 Cadillac Eldorado with a diesel. I looked after one for a customer and told him that when he was ready to sell it to let me know.
Obviously that time never happened…