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1979 Eldorado 5.7 diesel
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Discussion Starter · #1 ·
Hello, I am currently putting my 5.7l diesel v8 from 1979 (LF9) back together from replacing the headgaskets.
I would like to know if anyone has a clue what torque specs the bolts for the heads have. I assume its probably the same as for many other engines, so any number that seems good is appreciated:)
 

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Hello,
I can check the FSM for torque/sequence and lubrication reference later today. I don't know the diesels well but I understood the head bolts may have been one of the weaker points of the design. So if you sourced alternative bolts like the brand ARP I wonder if the torque will be the same.

I would recommend buying the FSM. I bought mine on eBay. It was reprinted. It's the thickest single FSM I've ever seen. It would be heavy to ship to you but it could go "book rate" so I would investigate the cost further. Book or media rate is normally quite a lot less than a standard rate.

Scott
 

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1979 Eldorado 5.7 diesel
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Discussion Starter · #5 ·
Hello,
I can check the FSM for torque/sequence and lubrication reference later today. I don't know the diesels well but I understood the head bolts may have been one of the weaker points of the design. So if you sourced alternative bolts like the brand ARP I wonder if the torque will be the same.

I would recommend buying the FSM. I bought mine on eBay. It was reprinted. It's the thickest single FSM I've ever seen. It would be heavy to ship to you but it could go "book rate" so I would investigate the cost further. Book or media rate is normally quite a lot less than a standard rate.

Scott
Please do, lmk if you find anything that could be relevant. :)
 

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Root,
I grabbed some of the pages from my 1979 Oldsmobile FSM which I thought you may find useful. I also captured a photo of the cover. I liked that manual enough that I bought one for my house and a second for my shop. The Olds manual is not as thick as the Cadillac All series FSM, still a typical ~7cm though, so if you find an Oldsmobile book it would ship at a cheaper rate I guess. DB2 had captures from a 1984 manual. It might be interesting to see if any of the information changed. I don't know that there are any differences but since the topic is 5.7L diesel and a lot of them were pulled and replaced with Goodwrench versions maybe GM learned or updated some best practices after 4yrs. My point being if DB2's manual says anything different than the 1979 manual it may represent an updated practice. That said I have occasionally found errors in FSM's... so in the end if information doesn't seem to make sense it should always be checked.

Scott
 

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1979 Eldorado 5.7 diesel
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Discussion Starter · #7 ·
Root,
I grabbed some of the pages from my 1979 Oldsmobile FSM which I thought you may find useful. I also captured a photo of the cover. I liked that manual enough that I bought one for my house and a second for my shop. The Olds manual is not as thick as the Cadillac All series FSM, still a typical ~7cm though, so if you find an Oldsmobile book it would ship at a cheaper rate I guess. DB2 had captures from a 1984 manual. It might be interesting to see if any of the information changed. I don't know that there are any differences but since the topic is 5.7L diesel and a lot of them were pulled and replaced with Goodwrench versions maybe GM learned or updated some best practices after 4yrs. My point being if DB2's manual says anything different than the 1979 manual it may represent an updated practice. That said I have occasionally found errors in FSM's... so in the end if information doesn't seem to make sense it should always be checked.

Scott
That looks like just what I need!
Thank you for your help.
 

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Ah I was about to upload the same instructions. 1979 Eldorado beat me to it
DB2,
Does it look like they just reprinted the exact same pages? I know you likely don't want to read through everything but sometimes you can catch things if the page breaks and structure changed. The 79 manual has so much information on the engine that it does seem like a must have if you're getting to the point of doing head gaskets. I'm pretty sure Root also posted a couple of weeks ago regarding the balancer as well.

I also included the figure with all of the Jxxx tools because the FSM loves to through a tool number out and who knows what Jxxx looks like. At least if you can see an image it may give you a clue regarding what they were trying to do.

Scott
 

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'84 Eldorado and Seville
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What do see that is different is sequence. In my '84 diagram 7 & 8, 9 & 10 are flipped around.
I also have the '81 to '83 service bulletin's and the diagram in it matches the '84 FSM.
The service bulletin said in 1980 new bolts are supposed to be used torqued different. The torque values do not match the '84 service manual. So I don't know if that different torque is because of the new bolts which that is what it reads like. I will upload those service bulletin pages.

'84 FSM
Font Line Parallel Paper Line art


Font Material property Parallel Monochrome Paper
 

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Interesting:
79 &84 show 176Nm or 130ft-llbs (129.8 ft-lbs so ok)
Service bulletin (June 81): 180Nm or 130ft-lbs (but 180Nm = 132.76 ft-lbs)

They do say they are using a new bolt in the service bulletin but what was their real target for torque? Were they simply rounding? It doesn't seem like enough of a difference for a different bolt class. The bolt heads in the bulletin I hoped would show a recognizable classification but I don't recognize those symbols.

Sequence: Making certain you go up to a partial value first, as stated in the bulletin, seems more significant than switching the 7&8 vs 9&10 positions. I don't understand why that specific change in sequence would matter but I would follow the bulletin and the 84 manual for sequence even though it seems it shouldn't matter. I hope it wasn't simply a time savings in light of the fact it should not matter (a tiny amount of jumping to the other side saved). Remember this was published around the same time GM paid an employee suggestion and made it official GM policy that employee would be spelled "employe" to save one key stroke... and as always when I started to type "employe" without two e's at the end I needed to backspace over one of the e's. Genius! And yes employee vs employe is a true story.

And what of the head gasket difference? They mention how they can be identified but by color. They never really explain the difference to look for.

I also forgot about those darn double sided bolts; the ones with a bracket mounting stud out of the other side of the head. Good luck finding those....

One other thing I noticed is they made certain to advise checking to see that the bolt head could actually contact the surface of the head. They mention chips but I wonder if they cut things so close they had a tolerance issue with depth of threading versus bolt length. Since they want you to check head clearance with a feeler gauge and no head gasket it seems like a good time to run each head bolt in "by hand". If it seems to touch, bolt-head to head-surface, then there should be no question it's good-to-go with a gasket.

Scott
 

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1984 Eldorado Biarritz, 1983 Sedan deVille
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I believe the later diesels were some of the first use of torque to yield bolts in an engine application like that. Now I could be wrong about that, but there were countless revisions to the head bolt setup on these. It would probably be worth it to get a subscription to AlldataDIY for a 1985 Eldorado with a diesel, it will have all the most recent TSB's with the part numbers for the upgrade kits. This is something you don't want to do twice. Good luck.
 

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Anthony,
Now that you mention it I do have the 85 Oldsmobile manual... same torque spec as the other manuals (not the service bulletin value). Sequence is the same as all of the other sources with the exception on the 1979 manual. Again I cannot see that would make a difference because either way you work from the center of the head outward with both patterns. I think it's the employee vs employe explanation.

On the 2-3 ft-lb difference in the spec on the bulletin I wonder if someone simply rounded differently and the number in all cases is 130ft-lbs. Going one step further 130ft pounds at the upper end of wrenches which go to 150ft-lbs which are pretty common. A torque wrench should be closest to calibration in the center of the range. So there is some danger of being on the high end. Had GM intentionally increased from 176Nm to 180Nm it would have been a 2.3% increase which would very likely be considered within tolerance. I think if this were my job I would get my torque wrench calibrated and I would want to know exactly the torque applied when I set-up for 130 ft-lbs.

Scott
 

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I searched around and found 22510580 and saw some on eBay and GM Parts Giant.
22510582 is superseded by 2250637 and I saw some on eBay. The others I didn't search for.

I presume the stamped id number on the gasket goes on the up side is the difference to identify the newer gasket.

Written by engineers who probably have never worked on one would be my guess. Much less even know what a torque wrench even is.

I'm guessing earlier torque wrenches the values were rounded and not spot on. The newer digital wrenches are pretty accurate as to the value you can set them at.
 

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1979 Eldorado 5.7 diesel
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Discussion Starter · #17 ·
I went with the torque specs that Scott submitted, 176 nm for the head bolts and I followed the torque specs for the other specified bolts aswell.
We'll see if it holds, the engine is almost back together so I can post an update when I have done a test start.
Thank you to everyone who posted, it helped out alot!

Olle
 

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Discussion Starter · #18 ·
Well, havent gotten it back together yet and I just encountered a minor obstacle. The pipe in the engine block that the oil dipstick sits in has somehow broken clean off at the base of the pipe, right at the block.
How can I possobly repair this? Is the pipe screwed into the block so I can order a new pipe and just replace it or do I have to JB weld it, which most likely wont hold?
Ive created a new thread about this but thought I would just update here aswell.
 

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Olle,
The dipstick tubes are just tapped into place. I haven't purchased a replacement in a long time but they do (at least did) sell them. Just be careful because the length might be a little different which could cause your stick to sit higher or lower. So try to get a known level with your original and then note the position indicated with the new tube.

How to remove the old one? If you had access to the oil pan side you could tap it out. If you do not maybe you could find a tight fitting sheet metal screw to thread into the ID of the broken tube. If you can thread something in and use a slide hammer you may be able to retract it with taking the oil pan off.

Let's see what others say. I'm suggesting the slide hammer technique may work but to be clear I've never tried it.

Scott
 
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