Can the wrong motor oil destroy your engine?

Please forgive my ignorance, but I'm at a loss right now. My mechanic replaced an oil pan on Monday. When I got the car back, I heard this loud clacking sound as I reached the top of each gear (it's a manual transmission). He took it back and said one of his guy's put in 10W20 as opposed to 10W40. He changed it out, but the noise never disappeared. The engine sounded HORRIBLE! He tried to replace some bearings, but the noise never disappeared. He suggested driving it and it might disappear. Anyway, I'm driving it tonight and the engine just shuts off on the highway. The engine sounded perfect before this guy touched it!!!!! I'm convinced that he destroyed my engine.....but I'm looking for some confirmation from some of you who are more technically minded. Thanks in advance!!!!!!!!!!!!!!

JD

I'm wondering if he didn't damage the oil pump pickup or knock it loose. If that happened, the engine would be oil starved at higher rpm, especially when cold and with a thicker oil (slower drainback to the pan). It would be the same as being a few quarts low.

You didn't happen to notice the oil pressure gauge did you? What did you mean by shutoff? Is it seized? I would bet the 10W20 story is BS - it's not easy to tell what weight an oil is after it's put into the engine. 10W20 is an odd weight to have in a shop anyway.

Tried to replace some bearings? Did he BILL yo ufor replacing bearings, because that's not exactly something that can be done in an afternoon at the garage without tearing into the engine pretty thoroughly...unless he replaced muffler bearings...

10W20, man thats a rare grade of oil. If it's as bad as you say and he told you to drive it this guy should have his shop closed.
First question I have is why did he replace the oil pan ? Thats not something that normally fails unless you whacked it on something.
I'm assuming it's a 4.0L XJ, that requires some dexterity getting the pickup back on as you reinstall the oil pan, screw up and the pick up falls out and won't pick up any oil.
This guy has to make good on it in my book but I would never let him even put gas in it after this.
Worst case and most likely your engine bearings, maybe rings are toast. I would start looking for a replacment motor especially after he let you drive it that way. Bad and damaged bearings do not fix themselves and a scored crankshaft needs a machine shop to fix it and repolish it.

If Im not mistaken some of the new Ford vehicles/trucks specify something like 0/20 wt or 10/20 oil due to a odd engine/lifter/cam? setup. If not used it voids the warranty.
do an oil pressure check with another mechanical guage or have another shop do it and document the findings. Sounds like they might have damaged it.

Thanks! As far as I'm concerned, I think he has to do whatever necessary to make this right - even if it means replacing the engine. In your estimation, is this a fair demand?

As for the oil pan, originally it was just a leak. I have an 85 XJ (2.5 4 cylinder). He suggested that oil was leaking from the oil pan.

Anyway, I think he realized that his guys messed up.....because once I brought it back, he replaced the oil pump and put in some new bearings (someplace near the bottom of the engine).....and he didn't charge me (although I offered to pay him for the parts). (Call me old fashion, but I believe in paying what I owe). But I was doing this based on my belief that he was sincere in his efforts. BUT now I believe that he KNEW the engine (or something inside the engine) was destroyed as a result of his guys' sloppiness and he didn't want to tell me.

I'm really amazed that putting in the wrong oil could have such a profound and immediate effect on your engine!!!!

Oh yeah.....when I said, "it shut off"......I meant that it seized.....right in the middle of the highway at 50 mph.

JeepDawg said:

Oh yeah.....when I said, "it shut off"......I meant that it seized.....right in the middle of the highway at 50 mph.

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OUCH!!!

How many miles was on this hooptie anyway?
Sounds to me it was ready to go to start with.
The wrong weight oil would not have hurt anything that quickly what was your oil pressure do you look at it?
How many times did you run it out of oil before you got it fixed?

I would concider talking to him in a civilized manner about him paying for replacing the engine and see how it goes. having to take this to small claims/civil court would be time consuming and the way it is in MN. you are responcable for the initial court costs but can include them in your claim against the other parties involved and then they have to pay you back. It could go on for months before your jeep see the road and he could possibly even win. When I say civilized, that is just to say you should not loose your cool as easy as it could be in this situation. If he is defensive and not cooprative start letting him khow that you'll be contacting the better buisness burreu and local news papers. Word of mouth can kill his buisness and any amount of Good PR is worth it's weight in gold

I don't think the motor oil would destroy your engine but a dropped oil pick-up sure would. Now that it seized it doesn't matter , the engine is toast. Time or a free re-build or replacement

Ridr said:

I don't think the motor oil would destroy your engine but a dropped oil pick-up sure would. Now that it seized it doesn't matter , the engine is toast. Time or a free re-build or replacement

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x2

if it was fine and reliable before you took it in, its def. the shop's fault. probably some rookie who worked on it and f'd up the pick up/pump

I'd have it towed to another shop and have them drop the pan and see what the cause was. If the pump pickup is laying in the pan or bent then they will find it. Get a letter from them stating the cause of the engine failure and take it with you. Infrmation is the key to winning something like this, you need solid evidence that it was work not done properly. Also see if he has liability insurance through the business, and do they have a warranty on labor and workmanship?

Even though it was an 85, the engine had 157,000 on it.....which isn't horrible. Granted, it wasn't new. But the engine had been rebuilt once before (when my father had it), so I am still inclined to think that it was this guy's fault...

I definitely agree on talking in a civilized manner - and thanks for the suggestion! I mean, I've been more than reasonable with this guy. And unfortunately, they would make mistakes in the past - which they readily fixed. As someone recently pointed out to me, just because he's a good mechanic doesn't mean his a good businessman. I think he has some sloppy guys working for him...

Currently, it's at another shop - the tow truck took it to their place. I'll find out on Monday what happened. I just want this nonsense to be settled. The mechanic has generally been reasonable, so I'm hoping that he will just replace (or rebuild) the engine. Considering how much money I've spent in there, the costs to him will be minimal.

The jeep was never run with no oil.... The leak was a few drops and it just started - I'm very particular and address problems as soon as they arise! (Since my father bought this new back in 1985, I'm very familiar with its history.....and I'm in the process of restoring it.)

About how much should a rebuilt 2.5, 4 cylinder.....or 4.0, V6 cost?

skyjackedxj96 said:

x2

if it was fine and reliable before you took it in, its def. the shop's fault. probably some rookie who worked on it and f'd up the pick up/pump

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We are definitely on the same page on this one... Monday morning, it was running fine - except for a very slight leak. Monday afternoon, the engine was making a "clacking" noise everytime I got to the top of the gear...

JeepDawg said:

Even though it was an 85, the engine had 157,000 on it.....which isn't horrible. Granted, it wasn't new. But the engine had been rebuilt once before (when my father had it), so I am still inclined to think that it was this guy's fault...

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From how you've described things here, it sounds like it was most likely something he did - and that he has a history of slipshod work. I give mechanics one mistake which they can rectify at their expense. If they make a second one, the vehicle gets taken elsewhere and they still pay to fix it, but my business goes elsewhere.

About how much should a rebuilt 2.5, 4 cylinder.....or 4.0, V6 cost?

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Can't help you with the prices, but you may want to check this thread for some thoughts on engine replacements. FWIW, putting a 4.0 into an XJ that originally had the V6 is no small task - the firewall is entirely different for starters.

Thanks for all the great feedback! This has been a stressful experience, but all of your insight has given me food for thought - plus ammunition!:viking:

Sounds like you were sent out with NO oil the first time!

Carnuck brings up a funny and good point, my aunt was in a shop for a oil change, they drained and changed filter, but forgot one step. motor seized up on her on the way home after violently knocking

JeepDawg said:

Please forgive my ignorance, but I'm at a loss right now. My mechanic replaced an oil pan on Monday. When I got the car back, I heard this loud clacking sound as I reached the top of each gear (it's a manual transmission). He took it back and said one of his guy's put in 10W20 as opposed to 10W40. He changed it out, but the noise never disappeared. The engine sounded HORRIBLE! He tried to replace some bearings, but the noise never disappeared. He suggested driving it and it might disappear. Anyway, I'm driving it tonight and the engine just shuts off on the highway. The engine sounded perfect before this guy touched it!!!!! I'm convinced that he destroyed my engine.....but I'm looking for some confirmation from some of you who are more technically minded. Thanks in advance!!!!!!!!!!!!!!

JD

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I'm inclined to agree with the others. It's most likely the oil pump pick-up was dislodged and the engine was starved of oil. What's left is basically toast. You could have the engine rebuilt at the mechanic's expense but I suspect you're gonna need a lot of replacement parts plus machine shop work done (reboring cylinders, new cam bearings, regrind crank journals, align bore mains, etc.). That means a lot of down time.
It would be cheaper and quicker to get a good used junkyard replacement 2.5 engine. Swapping a 4.0 I6 into an '85 chassis is a hell of a job and I wouldn't recommend it. The Chevy 2.8 V6 was an option in the '85 XJ so a 3.4 V6 swap would be much easier. It's a 60 degree V6 so it's narrower than the 90 degree Chevy 4.3 V6 and has more room to fit. Might be worth considering.