: Not to sound stupid....



Lazarus_Rooney
12-30-09, 12:42 PM
....but what exactly was so dreadful about the diesel 350 cadillacs? I understand that early fuel injection technology wasnt great, but i work at a car dealership as a detailer and get to see a lot of cars, the VW Golf TDI has come into its own and were selling them faster than any other car right now. Ive started to wonder, what if the kinks could be worked out of a diesel 350? add a turbo and some fancy computer things that i know nothing about, and away you go, or so i think.... im building a nuke shelter just in case i have this more wrong than i can imagine.

dirt_cheap_fleetwood
12-30-09, 03:17 PM
If I remember right the Olds 350 diesel was not designed to be a diesel, it was just a gasoline engine block converted to diesel.

outsider
12-30-09, 03:30 PM
My personal preference is to stick to a gasoline engine. I know a lot of people who prefer diesels but i'm not one of them. As for the 350 diesel...I don't know much technical stuff about it other than what dirt cheap said. I read somewhere it was just a regular olds 350 converted to run diesel.

teledan
12-30-09, 03:31 PM
Im not exactly sure about that specific car, but I think americans are afraid of diesels or something. Or maybe just ignorant to the advantages of the diesel engine. I blame the EPA :) I have always wanted to drop a Cummins 6BT into an old Caddy.

RocketFast321
12-30-09, 04:53 PM
.Ive started to wonder, what if the kinks could be worked out of a diesel 350? add a turbo

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sven914
12-30-09, 06:17 PM
It is a common misconception that the 350 diesel (LF9) was a converted 350 gasoline (L34). They were two separate engines that shared the same bore and stroke specifications. The first big difference is that the LF9 block is thicker and heavier than the L34. Because the internal pressures are so much higher in diesel engines, their walls have to be larger and thicker. A gasoline block cannot withstand the pressures of a diesel engine.

Other differences between the LF9 and L34 blocks are that the LF9 had the injector pump mounts cast into the lifter valley, solid cast main webs were used, transmission and exhaust manifold bolt locations are different, and the LF9 has a high a higher nickel content for both the block and heads.

Problems with the LF9 were in the heads and fuel system. Both the LF9 and L34 engines have the same head bolt head pattern, which does not provide adequate clamping force for diesel pressures. The fuel pump on the LF9 is chain driven, and the chain stretches over time, which cause fuel delivery at he wrong time. The larges problem was that the diesel did not come with an oil and water separator, which caused major corrosion problems in the fuel system.

Bro-Ham
12-30-09, 06:25 PM
Do some homework on this - there is plenty of info on the net. The 350 diesel was based on the gas engine although modified to be a diesel. There were flaws in the design which affected the longevity of the engine and most early versions were replaced by GM with an improved later version with the kinks worked out but the market had changed and performance was in and economy was out and GM's early poor diesel design killed a generation of buyers who were burned by the early dogs. From what I've read the 83-85 350 diesels are basically decent drivers although slow. They have to be better than the HT4100. :)

Bro-Ham
12-30-09, 06:31 PM
Sven, check your source because in 1985 I believe there was a water from fuel seperator added. In the 1985 Cadillac brochure, which, incidentally, shows that FWD Fleetwood model separate from the deVille :), anyway, it says about the 5.7 350 diesel which was available in RWD Fleetwood Brougham, Eldo, and Seville: "...this V8 Diesel benefits from an in-tank water meter pickup valve that continuously removes water from the diesel fuel and moves it in to a water separating fuel container conveniently located on the left side of the engine compartment." I think if one could find a 1985 350 diesel equipped Cadillac that it would be a super cool car! By 1985 hardly any buyers cared about fuel economy with the uplift of the Reagan economy in full swing. :) With Obama tanking like Carter we're ripe for big All American Cadillacs again!!! We shall overcome and drive big fun Cadillacs again!!! :)

sven914
12-30-09, 07:28 PM
Fuel/water separators were not apart of the LF9's factory fuel system. They were however added by the dealership. It might have been a Cadillac exclusive thing that diesel equipped Cadillacs got a separator on the assembly line, or that they were installed at the dealership (which makes sense because diesels had to be special ordered).

Bro-Ham
12-30-09, 07:54 PM
Well, we only know Cadillac had the separator in 1985 - the factory brochure doesn't mention it is dealer installed so I would bet it was a factory item and I would also bet all GM 350 diesels had it by 1985, if not before. :)

I~LUV~Caddys8792
12-30-09, 08:52 PM
I think it was Rick that said that most of the 5.7 Diesel Cadillacs weren't run like a diesel should be. Meaning they were only run for short trips which is death for a diesel engine. Nobody apparently mentioned to the owners that they weren't meant to be run like that. But then back in 1978 when they first appeared, Diesels were extremely new in the marketplace. Not even full size GM and Ford trucks would get them until 1982 & 83.

Bro-Ham
12-30-09, 09:01 PM
Bean counters @ GM wanted them made cost effectively at the expense of durability. The bugs were worked out by the early 1980's. The diesel engine should be driveable for any kind of driving but nobody cared about economy by the time GM perfected the 350 diesel. The reputation GM had made for its diesel as unreliable by that time killed the engine in addition to the fact that buyers wanted performance by the mid-1980's. Too bad since I love diesels and have owned a bunch of MB diesels which, with the turbo, were fun to own and comfortable to travel in although they were hardly as loveable as all the glitz and glamour of the 1970's and 1980's Cadillacs which also featured the unrefined 350 diesel. The 4.3 liter V6 diesel fitted to FWD Cadillacs in 1985 wasn't so bad, according to folks I've talked to who own them, although they are few and far between. That engine was designed and built specifically as a diesel and is beefier than the 5.7 350 V8 diesel GM originated. Here is a link to a car I entertained buying but opted against because the 1985 little Cads are not my favorite iteration of Cadillac. Take a look and buy it if you're seeking a fun and inexpensive diesel to tool around in. :) http://frontiermotorcars.autorevo.com/webtemplate.aspx?iid=588360

csbuckn
12-30-09, 09:46 PM
some info
http://oldsjunction.classicoldsmobile.com/oldsfaq/ofedsl.htm#EDSL%20DieselEngineDetail

snubdeville
01-01-10, 02:59 PM
I have been and I am still around GM diesel engines, and from my 20 years experience I can say they are all JUNK up until the LB7 Duramax....they should have went with Isuzu years ago.

jimmbo
01-01-10, 05:40 PM
I had the 350 diesel in an 81 GMC pickup at work. I hated it. Poor accelleration, any paperboy with two full paperbags could out beat it up to 20mph on a single speed bicycle. Noisy, sounded like a coffee can with 10 marbles being violently shaken. Unless it was plugged in at temps below freezing starting was hit or miss. Once it went below -18c(0F) it needed 2 blockheaters. It never ran right, it ran like it have an ignition miss, if it had an ignition system. I was told it was fine. After 3 years of complaining( to our fleet operations) it was sent out to a Detriot Diesel shop where it was decided the motor was shot and needed replacement. A new motor was installed and prior it being returned to me I stopped at the shop one night and took a look at it. It was running in the shop, so I asked the mechanic how it was doing. He replyed they had just 'returned from a test drive. it was running not bad, but it had this miss". I walked out shaking my head. I drove that junk for a couple more years, then one day there was knocking sound, very softly at this moment. I said nothing, just drove it. A week or two later, when I started it up BANG BANG BANG, left it running, went and found one of the mechanics, told him it was making a wierd sound and could he come see it. It could be heard about 150 ft away. The mechanic was... Shut it off shut it off. Never saw the truck again.

I~LUV~Caddys8792
01-01-10, 07:06 PM
I remember reading somewhere that a Diesel '81 Seville did 0-60 in about 19 seconds. An HT4100 Seville would do it in about 12 seconds. If that isn't enough reason to avoid the Diesel 5.7, I don't know what is.

I~LUV~Caddys8792
01-01-10, 07:43 PM
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Hmmm....they do sound nice though. Sounds like a 6.2 or 6.5L Diesel...

csbuckn
01-01-10, 08:07 PM
The blocks are not the same, the diesel is heavier because it has much thinker cylinder walls to handle the 22/1 compression. You can bore it out .060 and still have thicker cylinder walls then a stock olds gas block.

greencadillacmatt
01-02-10, 04:57 AM
I remember reading somewhere that a Diesel '81 Seville did 0-60 in about 19 seconds. An HT4100 Seville would do it in about 12 seconds. If that isn't enough reason to avoid the Diesel 5.7, I don't know what is.

Saying an HT4100 powered Caddy is faster than ANYTHING is a great reason to avoid whatever you are comparing it against. :yup:

Bro-Ham
01-02-10, 11:35 AM
It's too bad the 350 diesel was such a failure because it could have been the best thing in the world had the engine been a champ and later had a turbo hooked up.

I~LUV~Caddys8792
01-02-10, 11:41 AM
A diesel as noisy as that (although it sounds sweet) isn't very fitting for a big quiet luxury liner. Now, a Duramax on the other hand....

dkozloski
01-02-10, 06:34 PM
There were many conversions done locally with 53 series GMC two-stroke diesels put in pickups, box trucks and step vans. They were miles ahead of the junk you see now days. They were meant to last and did just that.

I~LUV~Caddys8792
01-02-10, 10:29 PM
There were many conversions done locally with 53 series GMC two-stroke diesels put in pickups, box trucks and step vans. They were miles ahead of the junk you see now days. They were meant to last and did just that.

I've seen those on Youtube, but the tough part about that idea is getting them DOT certified. Those old two strokes (god bless them) were about the most pollutin' thing you could buy. That's pretty much the only reason you never see them anymore, god knows they'd still be running.

Bro-Ham
01-03-10, 08:16 PM
Not to sound stupid, but I remember the 5.7 diesels sounding pretty quiet when they were new back in the day and sort of sexy and semi-refined. Maybe that sounds romantic but my memory of those diesels has always made me want to own one...stay tuned! It may be my entry into a 1985 FleetWood BrougHam. :)

77CDV
01-03-10, 11:11 PM
I have the same memory of them, Dave. They did sound more quiet and smoother than the contemporary European diesels. Pity they weren't better engineered.

Bro-Ham
01-04-10, 12:13 AM
Craig, Mercedes diesels sure are clackers. I had about a dozen of them several years back. I have to say they were sure nice road cars though. I'd take my chances on a really nice diesel Cad since it can't be any riskier than an HT4100. Plus, here in Florida it wouldn't have to plugged in. :)

I~LUV~Caddys8792
01-06-10, 08:00 PM
You want a clacky diesel? Here's an '82 Toyota Hilux, with the original 2.2L diesel I-4.

FE41AjBeVfI

Here's a '79 Eldorado, with the rebuilt 5.7 diesel.
o89fQMRIgEo

77CDV
01-07-10, 02:06 AM
^And people paid good money for that? Really?

I~LUV~Caddys8792
01-07-10, 09:36 PM
1986 Cadillac Fleetwood Brougham converted from 307 to the 6.2L diesel!

5nfXYCKjW18

Bro-Ham
01-07-10, 09:40 PM
OK, Please alert me to an A+ diesel 5.7 - I'm in the market. Olds 98, Buick Electra, or Cadillac deVille or Fleetwood. My yellow bird, or lemon drop as some of my friends call it :), needs a stablemate. :)

jayoldschool
01-07-10, 10:19 PM
The main problem with the 5.7 GM diesel was that the traditional buyers drove them like gas engines. With a diesel (back then), that was a big no no, and led to broken parts, and a bad rep. If you drive it like a diesel, it will be reliable forever, and give you great gas mileage while pulling just about anything you can hitch up.

Bro-Ham
01-07-10, 10:24 PM
Jay, please explain what you mean by the behavior that was a "no no" leading to broken parts. A diesel should be tuff, I always flogged my Benz diesels - they smoked more when I passed idiot drivers who pissed me off - - I always called it "smoking" them when I finally got enough speed to pass them and then lay on the gas and blow out the smoke screen! :) Ever so more important in the age of showing prius drivers who is boss. :) Towing?!?!?!? Are you kidding? It's a luxury car! :)

I~LUV~Caddys8792
01-07-10, 10:43 PM
OK, Please alert me to an A+ diesel 5.7 - I'm in the market. Olds 98, Buick Electra, or Cadillac deVille or Fleetwood. My yellow bird, or lemon drop as some of my friends call it :), needs a stablemate. :)

Wouldn't you rather have a really nice triple yellow '78 Eldorado Biarritz? :)


Jay, please explain what you mean by the behavior that was a "no no" leading to broken parts.

People would drive them for very short distances, not allowing the engine to reach operating temp, which is CRUCIAL in a diesel.

Bro-Ham
01-07-10, 10:47 PM
Chad, that's hokus pokus. A good diesel should run on obama salt/silica and still go a million miles. I think the early GM diesels had flaws but they did eventually figure them out but it was too late and buyers petered out. I'm yellowed out unless there's the smell of a deal in the air. A diesel has romance and the feel of an exotic. How many people do you know who drive a 5.7 diesel?? :) :) :)

Stingroo
01-07-10, 10:49 PM
Careful, in 4 years you could be asking that question without the word diesel attached. Scary.

jayoldschool
01-07-10, 11:09 PM
People would drive them for very short distances, not allowing the engine to reach operating temp, which is CRUCIAL in a diesel.

This is exactly the problem. Starting, then just immediately driving away.

I~LUV~Caddys8792
01-07-10, 11:12 PM
Chad, that's hokus pokus. A good diesel should run on obama salt/silica and still go a million miles. I think the early GM diesels had flaws but they did eventually figure them out but it was too late and buyers petered out.

I'm not just talking about the 5.7 diesel, but rather all diesels, even the ones used in full size pickup trucks, and bigger. My dad's been a diesel mechanic with the city bus system since 1980 and he's the one that told me that diesels aren't meant to be run for short distances.

FWIW, I like diesels, as long as they've been well maintained and won't be a money pit for me.

Bro-Ham
01-07-10, 11:12 PM
Booooooo.. Diesels never warm up by letting them idle. They only warm up after driving them. If the GM diesel is that weak then they deserved to fail. Florida may be the perfect place to test one of these weakliing diesels. I want one to clack and smoke around in. :)

greencadillacmatt
01-08-10, 01:00 AM
I want one to clack and smoke around in. :)

It would be like your Caddy is smoking a reeeeeaaaaally big cigar. :)

Cadillac_Fan
01-09-10, 12:03 AM
It is a common misconception that the 350 diesel (LF9) was a converted 350 gasoline (L34). They were two separate engines that shared the same bore and stroke specifications. The first big difference is that the LF9 block is thicker and heavier than the L34. Because the internal pressures are so much higher in diesel engines, their walls have to be larger and thicker. A gasoline block cannot withstand the pressures of a diesel engine.

Other differences between the LF9 and L34 blocks are that the LF9 had the injector pump mounts cast into the lifter valley, solid cast main webs were used, transmission and exhaust manifold bolt locations are different, and the LF9 has a high a higher nickel content for both the block and heads.

Problems with the LF9 were in the heads and fuel system. Both the LF9 and L34 engines have the same head bolt head pattern, which does not provide adequate clamping force for diesel pressures. The fuel pump on the LF9 is chain driven, and the chain stretches over time, which cause fuel delivery at he wrong time. The larges problem was that the diesel did not come with an oil and water separator, which caused major corrosion problems in the fuel system.


Insightful analysis and comparison. Mechanical engineer?

Stingroo
01-09-10, 12:32 AM
No, UberSven. lol

IIRC he goes to an automotive vocational school of sorts.

sven914
01-09-10, 01:07 AM
^Actually I'm done with the automotive college; graduated with an Associates in Automotive Technology. I'm currently working on my Bachelors in business operations and management.

csbuckn
01-09-10, 01:30 AM
FWIW? IIRC? I may be too old but I have no idea what these initials mean. Doesnt IIRC have something to do with racing?

sven914
01-09-10, 01:42 AM
^I can't understand what they say either... I usually have to look everything up on Urban Dictionary (http://www.urbandictionary.com/).

FWIW= For What It's Worth

IIRC= If I Recall Correctly

greencadillacmatt
01-09-10, 01:43 AM
cs, I'm 19 and I have no idea what those initials mean. Anybody wanna clarify?

csbuckn
01-09-10, 02:01 AM
^I can't understand what they say either... I usually have to look everything up on Urban Dictionary (http://www.urbandictionary.com/).

FWIW= For What It's Worth

IIRC= If I Recall Correctly

TSFSNIKWTLITF(Thats some funny stuff, now I know where to look in the future)

I~LUV~Caddys8792
01-09-10, 02:04 AM
I used to think IMHO was "in my high opinion", not "in my honest opinion".