Maintenance and contaminated fuel were big problems.

 

I bet they were also terrible in the really cold weather states too...

 

1984 Monte Carlo:
The SS was a hit not only in the car-buying public, (starving for some power after the hefty emissions regulations of the late 1970s) but also in NASCAR competition, where it continued to be a winning body style after the 1984 season successes. Production picked up, and 112,730 sport coupes were sold as 1984 year model coupes. An additional 24,050 had the SS option (with an 180 hp (130 kW) 305 V8 that saw a 5 hp (3.7 kW) boost from the previous year), having an asking price of US$10,700 (£6,890). The Monte Carlo SS was available with Strato bucket seats and floor console as extra-cost options for the first time in place of the standard split bench seat with armrest (the Strato buckets also returned as an option on the regular Monte after a two-year absence). The regular Monte Carlo came standard with a 125 hp (93 kW) 229 CID V6 (231 CID V6 for California) and a 165 hp (123 kW) 305 V8 was optional. Available for the last year in a base Monte Carlo was the 350 CID diesel engine, and there were only 168 manufactured. All engines for 1984 got the three-speed

automatic transmission

with the exception of three SSs at the end of the 1984 production run that received the Turbo Hydramatic 200-R4 transmission with overdrive.
Chevrolet Monte Carlo (4th gen) 1981-1988 - Ultimatecarpage.com forums
Source of above infor

 

I'd venture to say that there were a lot more Turbo 231s than there were diesel 350s. Wasn't that diesel based off the Olds 350 (which was different than the SBC)?

 

Yeah, there were alot more Turbo 231s. 13,839 built in 1980, but in 1981 they made only 3,027 "Turbo" Montes with that same Buick engine that had a hood scoop on the left side and 3.8 badges making them even rarer than the 1987 Aerocoupe of which 6,057 were built.

 

And yes, The diesel 350 was the Olds LT6.

 

Lou got it first.

It would be interesting to find a 350 diesel monte, im sure they're slow as hell but they'd probably get decent fuel economy lol. I've seen some of the oldsmobile diesels get up towards 30mpg