bcg88

Interesting article in Popular Mechanics. It pretty much blames the failure of the Olds diesel back in the late 70's early 80's on the US not adopting the technology.

Read on:

http://www.popularmechanics.com/cars...mobile-diesels

leepear

Just a comment, they were pretty bad. We blew one on a family vacation in the middle of who knows where and my friend who owned a dealership let me scrap out about 30 sitting in his dealership. Was a bad time for olds.

Lee

Nilsson

Typical American junk of the period.

Kyle's 77 Cutlass

So what they are saying is the olds diesel was junk, the only good thing was the block.

joe_padavano

As with the Vega and several other GM new technology products, one simple flaw, usually caused by cost cutting, has damned the entire line and the general press won't take the time to get the story right.

In the case of the Olds diesels, the primary problem was the lack of a water trap in the fuel system. Of course, this DOES make for a nice supply of bulletproof GASOLINE engine blocks...

330oldsmobile

What is the difference between the deisel and gasonline block?

Destructor

Caddy 4100 was a good one too.

75regency

The problems were the bad fuel quality , no water separators, only 10 head bolts per head,people drove them like a gasoline engine,didn;t use the correct diesel oil, and most didn't follow the recommended oil change intervals of 3000 miles. You CAN NOT do that with this type of diesel. It needs to warm up before driving, and have the oil changed no more than 3000 miles between and use diesel only oil. I own 3 of them and they run flawlessly. I actually enjoy driving them and getting 25+mpg in a big car. One I have has the original D-block which was suppose to be the worse one. It runs great. Don't knock what you hear. There a lot of us out here who like this diesel. There is a forum just for the olds diesel. In case anyone was wondering, they are a great motor and will last hundreds of thousands of miles as long as you let it warm up and change the oil every 3000 miles and use diesel specific oil.

Boldsmobile

There is a brand new diesel crate motor on craigslist, need a spare?

Kyle's 77 Cutlass

Also which is very true, may of been one of the problems with them,people drove them like a gas

jensenracing77

i agree completely. my dad just got rid of his last diesel car. not because of the engine. he hit a deer and totaled it. he was getting 28 MPG consistently. he drove it on I-70 for one tank and got right at 30. these engines had some problems but i still like them. but i also like the Quad 4 engine

jaunty75

Some of this may be true, but it doesn't cover the entire issue.

My father, who did everything exactly by the book in maintaining his '79 Toronado diesel and had all service done at the dealer where he bought it, still had the bottom fall out on it at 25,000 miles. Problems experienced by these diesels was not caused solely by poor maintenance. There was a class-action lawsuit against GM at the time about this, so this was not the occasional isolated problem, but rather it occurred nationally on a large scale. The owners won the suit, and, in the end, my father collected some money.

75regency

I would love to have a new crate motor spare.. where at?

rocketraider

Part of the problem was that GM advertised it as lower maintenance than the gas engine- and people took them at their word. The American car owner being what they are, most didn't maintain them at all. Nobody ever told them that just because it didn't have spark plugs and an ignition system (GM rationale for "low maintenance") did not mean it didn't need to be maintained properly.

There was a reason Olds was tasked with bringing the Diesel to fruition. At the time they were still recognized as having the best engineering department in GM and the 350 gas block was one of the strongest GM had. So Olds got the job of developing GM's passenger car Diesel. The Engineering staff involved all admitted they learned as they went, because they didn't know anything about Diesels.

Everyone I've known who got high miles out of their Diesel kept it on a rigorous maintenance schedule, used the best fuel and oil they could get for it, and installed additional fuel filters with water separators. Most kept a block heater on it even in warm weather and had few short trips.

I'm convinced small Diesels are part of the future. Europe and Asia use them but for whatever reason the US does not take to them.

Now, if GM had elected to turbocharge the Olds Diesel and get a little more oomph from it once the initial teething problems were addressed, I think they'd have had a winner.

But you see what bean counters can do to an otherwise worthy project. Trouble was THEY didn't take the blame for the Diesel's relative failure, along with other cost-slashed GM projects they sabotaged.

Kyle's 77 Cutlass

are these the same diesel's that were in the Chevy and GMC half ton's in the early 80's?

oldsmike1972

As several have mentioned, the lack of a quality fuel cleaner (dirt and water) was the largest problem on those motors. A close second was head gasket failure and that was primarily due to not using the next size up head bolt.

As a gas engine, they are darn near as thick as the Nascar block. Stuff a 425 crank in there (offset ground of course) a very light reciprocating assy, heavy compression and a monster cam and you got gobs of horsepower. Anything can be broken but those motors are significantly stronger than everything else in the Olds lineup from a performance standpoint.

MDchanic

No.

These are the Olds 350 (5.7L).

You're thinking about the GM 6.2. Completely different engine, designed from scratch as a diesel, no interchangeable parts whatsoever. It's the one that powers the earlier (pre-turbo) Humvees.

The 6.2 is an underpowered but bulletproof 500,000 mile motor.

- Eric

jensenracing77

they had some of the olds diesels in the trucks also in the early 80s. my had had one new back then.

Boldsmobile

http://boston.craigslist.org/bmw/pts/2305728189.html

Kyle's 77 Cutlass

Well in shop class years ago, a friend of mine had a 83ish. That Chevy had a 5.7diesel in it and if I remember right it had a tag on the tail gate Chevy 5.7 diesel

Kyle's 77 Cutlass

Also these 350's, is the deck hight the same as the regular 350 OB? Also I've been reading that they have a 3" crank journal,which you can drop 425/455 crank into it to make a stroker.Since I am not good with engine math, if you did this to an engine what would happen to it as in end result of size,HP,torque, lets say around 10/10.5to1 compression? Is it still a small block? Also I read that this diesel had a 22.5 to 1 compression. No wonder it had head problems

rocketraider

22.5 CR is nominal for a Diesel as it relies on heat generated by compression to ignite its fuel mixture. Yeah, Olds should have gone to more and larger headbolts to handle that, but, as stated earlier, they admittedly knew nothing about Diesels when they went in. And GM being GM, wouldn't hear to them using outside experience. Not even from their in-house Detroit Diesel Division.

Typical GM stupidity from the time.

The 5.7 Diesel was used across the board in Diesel-equipped passenger cars and light trucks thru the mid-80s.

MDchanic

Okay. When you said that, I thought you meant it in comparison to the very common 6.2 that was made from the early '80's into the early '90's, and then modified to make the electronically controlled 6.5 turbodiesel.

Yes, they put the Olds motor into other divisions in the early eighties, and they overlapped the 6.2's for a number of years.

You can tell the difference because the Olds motor looks like an Olds motor, but the 6.2 looks kind of like a Chebby big block.

- Eric

Kyle's 77 Cutlass

Well I did some looking, my 07 Duramax has a 16.5to1 ratio,there 22.5 may of been a little much?

MDchanic

The Duramax is turbocharged.

22.5 is for normally aspirated engines.

- Eric