Technical Oil Pump Failure Question

I have a 53 Buick with a 76 Buick 455 engine. I know the basics of engines, but am not a mechanic. I had a leaky gasket on oil filter bracket and took it in to a shop for them to replace it. Long story short, they didn't prime the oil pump after replacing the gasket. I picked the car up and was down the road a quarter mile or so when I noticed it knocking and had no oil pressure. I immediately turned around and went back to the shop. They started it several times trying to figure out the problem. A experience mechanic later figured out that the lessor experience mechanic had forgot to prime the pump after replacing the gasket. They primed the pump and it now has good oil pressure. I went to pick it up and it had a "knocking" sound coming from, what seems to be the front of the engine and was idling semi-rough. I told them I wanted a more experienced mechanic check the car out for damage before I would except it back. My question is: What could have been damaged when engine had no oil pumping for that 1/4 mile? What could the sound most likely be? I don't want them to try to blow smoke up my butt when I go talk to them on Monday. Any advice or information you all could give me would be appreciated.

 

In my opinion (check my signature, i see a lot of engines internals) the pump is scratched, main and big end bearings are toast (especially that one which is knocking), and it is possible that at least one cylinder (and piston) has to be replaced. That is the worse option. But if You can hear knocking there is no good option. Good luck talking with them!

 

first things, if your car looses oil pressure , shut it down and don't drive it anywhere till you find out why. Do you have a lamp or gauge? red (big) warning lamp is hard to beat, I used to like gauges but now I like the big red lamp.
Id say, at a guess you have damaged at least the crank bearings, if I did that, Id drop the sump and inspect the rod and main bearings for damage.

 

read this and get back to me on your original question.

http://datinmanspeaks.blogspot.com/2013/09/anyone-got-any-luck-i-can-beg-borrow.html

 

On a buick the "oil filter bracket" is the bottom of the oil pump. Change the gasket and the pump is dry. If they used a gasket that's too thin it will chew up the bottom of the pump and fill the oil galleries with metal shavings, too thick a gasket and the oil pressure goes to hell once it starts to warm up.

 

My bad, I had Oldsmobile on the brain

 

Thanks for the replies. I don't know what I was thinking when I saw no oil pressure. I had thought maybe they had taken the sending unit wire off and forgot to put it back on or loosened it when they did the repair and that is why I wasn't getting any pressure reading. Plus, I was close enough to the shop (I could still see the shop from where I stopped and turned around) and so I just turned around and went back. Everyone I have talked to all agree that major damage had to have happened. I just hope the owner of the shop has some integrity and will make it right. Either way no bueno

 

Interesting. So the pump is external?

 

Yes...it is.

 

Thanks. I've sometimes pondered the merits of an easily serviceable oil pump but apparently it has it's down side. I've played with many GM engines but never knew the Buick had this feature, surprised they differed from the others.

And I wouldn't settle for anything less than a complete rebuild. Bummer.

 

The 455 oil pump uses a paper thin gasket, a too THICK gasket will cause problems. (master Buick tech)
A dab of vasoline or grease is all that is needed to prime the pump. So the shop never fired the engine after replacing the oil pump gasket??

 

Sounds like the bottom end is toast. Knocking, idling rough, it was just seconds from seizing up completely. Any time you have one of those pumps apart you are supposed to pack the gears with a light grease so that when you start it up it will prime with oil. The shop owes you a new engine, hope that they are stand up guys and pay for their mistake, if not, you may have to get legal council.

 

I put a t in the oil line of the mechanical gauge and run an oil light from there .
You are sure to notice the oil light come on before you ever see the gauge drop!!!
My dad and uncle done this for years on there race cars

 

Sad affair, engine noise? Stop now, not another foot!!!

 

Knocking in the front of the engine. that is the last place on the crank to get it, so it could be a rod or a main. In a quarter mile your bearings should actually survive if they were getting oil before and you were not hammering it.

Wrist pin, lifters, timing chain. rockers, valves? The timing chain should have survived but anything in the top end would have been oil starved.

I would need to hear the noise to actually answer the question.

 

The owner has two separate shops. One a automotive repair/body shop and the other is just a classic car restore shop. I stopped in at the classic car one since it was closer to me. I originally went in to get an estimate on some body work. While there, I asked the owner about replacing the leaky gasket. He told me to drop it off and he'd have one of his guys replace it. They normally don't do mechanical repairs at this shop. The guy that replaced the gasket was young and inexperienced (I found out later) and didn't prime the pump after her replaced the gasket. I actually researched the issue that night and called him the next morning and told him that he didn't prime it. Others that I have spoke to about this said that it probably caused damage to the engine, but I was hopeful that it didn't. When I went in to pick it up I didn't even drive it, because I heard the knocking sound coming from the front and wanted one of their experienced mechanics at their other location look at it. They moved to their other location and now I'm waiting to hear back from the owner. From my understanding he is reputable shop, so I hope he will do the right thing. I do know they had started the car to make sure it wasn't leaking after they replaced the gasket. Why they didn't check for oil pressure I don't know. I'm just assuming it was inexperience of the mechanic for this costly oversight. It just sucks waiting the whole weekend to hear back on what they're going to do about the whole situation.

 

I hope everything works out for you. This is upsetting to hear. They need to replace or fully repair your engine!

 

This is one weakness of the Buick V8 design, the oil pump is in an external aluminum housing and it wears. It must be primed with Vaseline if taken apart otherwise it won't get pressure. The oiling system design itself isn't the greatest either.

I'm a Pontiac guy and not a Buick expert by any means, but this is one fairly well-known problem with Buick V8s.

 

Holy crap, what a bag of worms. The guy who directed the kid to change the gasket apparently didn't know to pack the pump and the kid certainly didn't know. This falls into one of those weird categories like putting a timing chain on a Y-block, but hey, in the end, the shop owner is responsible for the screw-up. I hope he steps up to the plate for you.

 

Something you might consider: If your engine was not fresh, or if you want to make any changes, cam, compression, etc., you could offer to pay some portion of a rebuild if you have the bread.

Do repair businesses have insurance to cover such matters?

 

Any updates? Pete

 

Update: Went into the shop and met with the owner. They seem to think its the timing chain/gears making the noise, which he said that failure is unrelated to the starvation of oil. I told him that when I brought the car in all it needed was a leaky gasket fixed. There were no "other" sounds emitting from the engine. He said, they were going to drop the pan and inspect the bearings and check the timing chain and gears. He assured me that if anything was damaged related to the failure on their part to prime the pump, that they would accept responsibility and repair it. From everyone that I have talked with, they say he is a honest and straight up guy. We'll see. Could the oil pump issue cause the timing chain issues? I would think that if there was no oil flowing to the top end, that anything related to that would have excessive heat to such things as bearings or any type of gaskets and in turn cause failure. Like I said, I'm not a mechanic. I just know the basics and theory. But I am getting a crash course here... Thanks for the help guys.

 

They're supposed to. I do. Though I wouldn't put it thru my insurance. I'd pay out of pocket. Insurance is pricey for businesses.

I had a kid forget to out an oil cap on. Customer drove it for days until it caught fire. Everything on too melted (newer car, lots of plastic). Someone put it out before it was gone.

I have her a loaner for a couple weeks. Bought a parts car. New hood. Changed all wiring and lots of plastic parts. Cost me at least a few grand.

That was a couple years ago. Customer is still diving car, and I still have customer. (But damn, do I ever double check that oil cap every oil change).


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Just a thought - The shop that made the mistake in the first place is now going to examine the engine for damage to determine if it was their fault and who should pay for it. I really don't think I'd have much confidence in their assessment of the damage and if by some miracle they did determine it was their fault, what sort of repair would they do??

Am I too cynical?

 

Something isn't adding up here. If the engine was only run a 1/4 mile, there should have been enough oil on the bearings to last getting back to the shop. Engines are pretty friggin tough, they can actually run a while with no oil (not advisable). But the knocking you speak of sure does sound like a rod or a main. Is the knocking proportional to engine RPM? Or does it stop at speed and knock at idle?

I used to have an old 289 SBF in a 63 Fairlane that I ran for quite a while with very little oil and it developed a rod knock. That engine always had very low oil pressure, 4 lbs at idle and like 35-40 lbs running down the road. I put SAE30 weight in it and it would be just fine at speed, but would knock a bit at idle and hard if you accelerated hard from idle before the engine had a chance to build some oil pressure. I took into account the engine's issues when I drove it, and had no problems, even driving it 600 miles per week for almost a year. I sold it to my father in law who also drove it a while without issue before ultimately swapping the engine and trans. Even still, if you've got a knock that you didn't have before, the shop owes you a rebuilt engine.

 

Update: Got a call from the shop and went in this morning to see what they had found. They pulled the timing cover and this is what they discovered. One of the bolts that hold the timing chain gear had backed out over time. Whom ever built the engine did not use Loctite or a lock washer on either of the bolts holding the gear on. The mechanical fuel pump armature hit the bolt that had backed out and had snapped off. The pump was still operable even with the arm broke off. What was left of the arm was just enough to hit the backed out bolt on each revolution and still pump fuel. The ticking noise was the arm hitting the bolt. You could see scouring where the broken piece of the fuel pump arm had got caught in the bottom timing chain gear. All the evidence was there. The mechanic showed me everything that was wrong when the motor was rebuilt years ago. There was a bolt broken off from the timing cover that wasn't extracted and should have been, among other things. So I can't blame the shop for this failure as it doesn't relate to the oil pump priming issue.

 

OK, so you are on the hook for the fuel pump related issues, but you still have no oil pressure....

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No..the oil pressure was fixed when I went to pick up the car. They had primed it and it was running good pressure. However, it was making a knocking noise from the front of the engine. So I didn't take the car home and wanted them to see what was causing the knocking sound. I assumed the noise was due something related to not priming the oil pump, but it wasn't. Hope that clarifies it.

 

LOL not laughing at your dilemma but the honest statement.

My Ol' Man was a mechanic before the war, and died in '03 (no condolences necessary), he was still wrenching the year before he dies so he was only fully retired for about 1 year. As long as I can remember he told me that all mechanics are dishonest.

I am sure that your man will straighten it out for you, my Ol' Man would have. Good luck with it.

 

Ok, good to know of a shop in this area that stands behind their work.. so how about the name and location.