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Goodwrench 5.7 GM Diesel engine


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The Goodwrench replacement engine should be very durable. Most of the points have been covered. Use the correct oil in it, keep it changed regularly and it should last a long time.

I think the low sulfur diesel is bad for the injector pump as the sulfur is what lubricated the pump. You might want to ask Goodwrench what to do regarding the use of the low sulfur fuel.

A good substitute for the sulfur is 2 cycle oil. I mix 1 oz oil to 1 (gallon) diesel fuel. I also buy my 2 cycle oil at Walmart in the gallon jug.

Edited by Ed Hall
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Keep the oil changed regularly... use Diesel rated oil ONLY.

Change the fuel filters every once in a while.

I am not telling "YOU" to do this... it is just food for thought.

I always did two things to any of the GM Diesel cars I had.

Put TRUE DUAL EXHAUST alll the way from the manifolds to the rear bumper and include and "X" pipe in the exhaust, up close to the transmission.

If you look at the factory exhaust, it is similar to the exhaust found on the gasoline engine.

In my humble opinion, the exhaust system chokes the engine and doesn't let it breathe.

The other thing I did was find a "GOOD" diesel mechanic that knows what he is doing, and have the pump "TURNED UP".

If he don't know what you mean when you say that... find another mechanic.

Both of those mods... done together... seemed to "INCREASE" both horsepower and fuel mileage, while DECREASING the amount of smoke the diesel would put out on heavy acceleration.

The only other thing I would add to the things mentioned would be a set of exhaust headers. GM must have been counting pennies because these simple mods really wake up these old diesel engines.

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Keep the oil changed regularly... use Diesel rated oil ONLY.

Change the fuel filters every once in a while.

I am not telling "YOU" to do this... it is just food for thought.

I always did two things to any of the GM Diesel cars I had.

Put TRUE DUAL EXHAUST alll the way from the manifolds to the rear bumper and include and "X" pipe in the exhaust, up close to the transmission.

If you look at the factory exhaust, it is similar to the exhaust found on the gasoline engine.

In my humble opinion, the exhaust system chokes the engine and doesn't let it breathe.

The other thing I did was find a "GOOD" diesel mechanic that knows what he is doing, and have the pump "TURNED UP".

If he don't know what you mean when you say that... find another mechanic.

Both of those mods... done together... seemed to "INCREASE" both horsepower and fuel mileage, while DECREASING the amount of smoke the diesel would put out on heavy acceleration.

The only other thing I would add to the things mentioned would be a set of exhaust headers. GM must have been counting pennies because these simple mods really wake up these old diesel engines.

I agree about the headers.... I forgot to mention that.

Back then I used Hooker headers, made for a 350 chevy pickup with REAL LONG collectors to increase torque.

They obvisouly didn't make them for Cadillacs and Olds 98's... :):)

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  • 7 months later...

Hey guys, my son just bought a 78 Cadillac Seville. 5.7 diesel engine.

Since I know very little about diesel engines, I might be hanging around here quite a bit.

The issue I'm having is the fuel return line connections are cracked and leaking where they connect

to the injectors.

Any idea where I can find new injector connections for this car????

I've been looking inline for a couple hours abd can't seem to find ANY sites or suppliers for these parts.

Thanks in advance for ANY advise or suggestions, Dave

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Rock Auto lists a selection with prices varying from $20 to $121 each, with the zinger being AC/Delco. Standard Motor Products offers OEM quality at value prices of a lot of items and offers them for $34.

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-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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A couple of things to keep in mind with the old 5.7 diesel engine. Be sure to use the correct engine oil in it - Rotalla diesel oil or an equivalent Mobil Delvac oil.

Another thing is the injector pumps on those engines needed the sulfur in the diesel fuil to lubricate the pump internals. Today's diesel is so low in sulfur contend that an additional lubricant should be aded to the fuel. I'm not sure what people use but I'm sure if you visit www.Olds-Diesel.com, there will be a ton of information on keeping the engine in reliable operating condition.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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Coworker had a 1980ish Olds Regency 98 with the 5.7L diesel. He purchased it used from an Olds dealer with low mileage and only a few years old. He drove it about a year or two (not sure today) back and forth to work all over logging about 25,000+ miles a year. One Monday AM he never showed up for work. We did survey work for the state govt so we were always out on a highway project so we never heard from him. Next day he comes in driving another car, a used Mercury Marquis. Said he was about 25 miles from home (150 miles to job site) on Monday and the engine up and quit going down the road. Would not start, nothing. So he had it towed back to the dealer. They gave him a car to use while they tried to determine why it quit. Next week he came back with the Mercury (he bought) and said the crankshaft in the engine broke in half, engine was shot. He then tried for months to find a replacement engine and could not find anything worth using. Olds had no replacement engine they could order, they told him he would have to buy all the parts and literally piece an engine together at a cost of over $3k back in the mid 1980's. He went and found a salvage yard to install a used 350 gas engine and he gave the car to his daughter and never bought another GM vehicle to this day.

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Coworker had a 1980ish Olds Regency 98 with the 5.7L diesel. He purchased it used from an Olds dealer with low mileage and only a few years old. He drove it about a year or two (not sure today) back and forth to work all over logging about 25,000+ miles a year. One Monday AM he never showed up for work. We did survey work for the state govt so we were always out on a highway project so we never heard from him. Next day he comes in driving another car, a used Mercury Marquis. Said he was about 25 miles from home (150 miles to job site) on Monday and the engine up and quit going down the road. Would not start, nothing. So he had it towed back to the dealer. They gave him a car to use while they tried to determine why it quit. Next week he came back with the Mercury (he bought) and said the crankshaft in the engine broke in half, engine was shot. He then tried for months to find a replacement engine and could not find anything worth using. Olds had no replacement engine they could order, they told him he would have to buy all the parts and literally piece an engine together at a cost of over $3k back in the mid 1980's. He went and found a salvage yard to install a used 350 gas engine and he gave the car to his daughter and never bought another GM vehicle to this day.

Something doesn't sound right with that story - there were GM Goodwrench crate diesels available. Not sure how many miles were on the Regency but at 25,000 miles per year, I'll bet it was well over 100,000 miles. People think vehicles should be lifetime vehicles. If they were lifetime vehicles, they would be so expensive, no one could afford them...

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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I found no hits on Snopes for "Oldsmobile" or "Crankshaft" and hits on "Diesel" were not related. I did a web search on "Oldsmobile broken crankshaft" and found only one guy in Chile who put together a home-brew hot-rod Olds 4-4-2 with a bow-tie 350 and somehow the damper wheel bolt stripped out and the damper wheel caught on the frame or whatever and the key gouged a spiral on the crankshaft tip. I couldn't find anything on anyone breaking a crankshaft on *any* car.

The guy might have lost the damper wheel and the end of the crankshaft was damaged, like the poor dude in Chile. I've heard of that happening on cars that did not have the damper wheel properly torqued. If the bolt is over-torqued on some cars, the bolt will fail and the damper will come off, and the keyway may be damaged while the damper is loose. If the bolt is under-torqued it can loosen or come out with the same result, only slower and thus more likelihood of keyway damage.

40 years ago I heard that it is possible for an early Chevrolet 235.5 cid straight six (1949-1953 model years) to break the crank between numbers two and three on a standard shift if the damper wheel is broken or frozen up. Apparently a Powerglide torque converter provides enough damping to keep this from happening, or maybe just the standard shift people would wind them up enough to scatter the motor. But I never heard of one that had done it.

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-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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I "THINK" I remember my brother having an Oldsmobile diesel that broke the crankshaft...

If I am remembering it right... when it broke, it also broke one of the main bearing webs off of the bottom of the block.

He works nights... I will call him later today and see if I am remembering it right.

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Its not BS, it happened. Just because you never heard of it does not mean it did not happen. His engine was beyong repair it was so damaged, he was travelling at the speed limit (or more) when it quit.

I don't think he had over 100,000 miles because he bought the car used with very low mileage from a GM dealer, it was 2-3 yrs old if I recall correctly. I do recall the reason it was said of why it was traded in was the owner wifes was getting sick from the diesel odor. I think back then the warranty was 3 yrs / 36,000 miles. I distinctly recall he could not get a new crate engine from GM at the time this happened.

Edited by Z15
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Oldsmobile Diesel
Based upon the 350 cubic-inch Olds gas engine, the diesel debuted for the 1978 model year to much fanfare. The promise of the future, it allowed big car comfort with small car fuel economy.

Contrary to popular belief, the engine was completely different than its gasoline brethren, but it did look the same since it needed to go down the same assembly line and fit into vehicles that could be either gas or compression-ignition powered.

The block was much sturdier and the crankshaft mains and crankpins were 0.500-inch bigger, measuring 3.00 inches instead of 2.5 inches.

The crankcase was heavier and the pistons were fitted with full-floating pins. The block was so good that during that era many drag racers used it to make big power and it was known to stay together.

Then what happened to the Olds Diesel to give it such a poor reputation and the impetus for a class-action law suit?

The engine suffered from poor familiarity by the consumer and Olds service personnel along with the lack of a water/fuel seperator and drain in the fuel system.

This was compounded by a flood of very poor-quality diesel fuel into the market place shortly after the engine's introduction.

Any moisture or dirt that would get into the high-pressure Roosa Master injection pump would cause some of the parts to hang up. This could have occurred for only a second, but that was enough time of an incorrect fuel inject cycle that would allow cylinder pressure to peak and overcome head bolt tension or break down the head gasket.

The driver may have only sensed a slight shudder but the damage was already done. The injured head gasket would then let coolant seep into the cylinder and since there is little quench volume in a diesel, the uncompressability of a liquid was a theory very quickly reinforced.

Something had to give and it often was a piston, connecting rod or crankshaft but it spelled disaster either way. In addition, both the dealer body and the consumer often used the incorrect oil for the engine, creating further service issues.

The Olds Diesel, when cared for properly, ran for hundreds of thousands of miles, but only in the hands of an experienced diesel operator.

Other than that, it makes a great gasoline race engine block.

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I talked to my Brother last night...

The crankshaft broke on his Olds 98.

When it broke, it also broke one of the center main bearing supports from the bottom of the block.

He sold it AS IS and bought another car.

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Any word about crate engines? That could have been true for the time it happened to Z15 too, even if they were listed, because the network might have been out-of-stock. On an old, low-volume assembly, that can mean a wait of a few months. That happened to me in 2006 when I was rear-ended by a Honda, which scratched my bumper cover, ruined the left bumper shock absorber, and wiped out my exhaust system behind the rear Y, including the tips on the left side. The tips come with the mufflers for the 1997 ETC and the mufflers were out-of-stock at GM, with an estimated wait time of 90 days. That's why it had 2007 STS tips from that time forward.

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-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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  • 8 months later...

We had one of these 350 Olds diesels in a Delta 88 I think an 84, because of the low sulfur we had to *smurf* Howe's diesel treatment to the tank on every fill up, besides the car sounding like a old school bus at idle and smelling like one, it ran fine, wasn't fast but got around just fine, until the injection pump went out and we scrapped the car. It leaked like a old Detroit diesel semi tho lol.

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Actually, I think you had to *add* Howe's diesel treatment to the fuel.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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Forum software has an automatic editor that looks for "bad" words, or words that are not family-friendly four our young friends are just learning to read and practicing on the Internet. It turns them into whatever you like. This forum turns them into "*smurf*" which is as good as anything, I guess.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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  • 6 years later...

For Sale is one of these 350 Goodwrench 6cyl's

I purchased it 20 years ago on an engine stand as a new engine for a Jeep project- well I wrecked the rusty Jeep- and this engine has stored inside my house for 20 years! 

Ive never run it- dont know much about it- 

But its in good shape and I would like it sold..

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