Found one mounting bolt in the bottom of the pan...

I realize that my discovery pales in comparison to what many of you on the board have discovered after dropping your oil pan on the M60 motor...so by finding only one bolt in the pan, I consider myself lucky and would not have started a new post to inform of such trivial info (relatively speaking).

Unfortunately, I also found what appears to be the head of a connecting rod bolt that has sheared.

Good news = I can at least see the location of the sheared bolt, which is directly behind the oil pump, but have not attempted to remove it as of yet (still in shock)...so I guess it will only be good news if I can actually remove the shank of the sheared bolt from the engine! (reference p/n 11-24-1-747-131)

Bad news = I obviously have no idea when this bolt sheared, what caused it to shear, and what/how much damaged may have been caused as a result. Any ideas???

There were No flakes/chunks of metal in the pan or in the filter, and the only indication concerning the lubrication system was an;

-'Oil Level Sensor' message at engine shutdown (not all the time/no pattern)

- Or, if I would goose the throttle while in park I could create the 'Oil Level Sensor' message...

Admittedly, after verifying proper oil quantity, I would simply dismiss this message as a nusiance and figured I would replace the sensor at next oil change - this was part of the reason for dropping the oil pan.

The other factor was that when I removed the oil pan for
a) the first oil change as the new owner (Jun05/95k), and b) to verify the integrity of my oil pump bolts (made aware of this problem prior to purchase thanks to this board), I tightened all the bolts that connect the two halves of the pump together and neglected to tighten the mounting bolts/nuts. Duh!

Based on the given information, what are your opinions regarding repair...

1. My plan is to remove and replace the sheared bolt (if possible), and replace both connecting rod bolts - Tq to spec. (Anyone know the Tq value?)

2. Disassemble, reassemble, and reinstall oil pump using Loctite on nuts and bolts. Installl oil pan with new oil pan gasket.

3. Service with fresh oil and keep motoring!!!

Or, am I dreaming?

onelivefive

Honestly, if it IS a rod bolt that's come apart, you're talking miracle it's not knocking. The bolt probably came from somewhere else. If it turns out the bolt IS a rod bolt, I wouldn't put it back together, I'd pull the motor, break it down, and start measuring parts to make sure they're within tolerance. Reusing parts like that without checking them out is just asking for trouble.


And please, take and post pics!

I don't plan to reuse any parts just replace the sheared bolt...

Pulling the motor is out of the question for many reasons, and besides, the car was running fine prior to this find...maybe I got lucky!

I cannot post pics at this time, but you can refer to the excellent posting and pics by 'gboezio' and shelbyz4u2nv [Jan 23, 07]...there is one photo by shelbyz4u2nv that shows the bolt that I am referring to (it is like a reverse or outside Torx head and it sits right behind the oil pump).

Thanks for the suggestion!

i say u replace the rod bolt and see what it does...

no point in pulling the engine out and taking it apart to check tolerances...
because if u replace the rod and the warning light flickering goes out, u're good, if not u're gonna have to pull the engine out anyways....but probably waaay down the road when u're prepared for it.

By no means am I an engine expert but if you are going that far you might as well check the rod bearing on that cylinder just to check for any advanced wear due to the "potential" incident of that bolt shearing

All else, your plan sounds spot on to me

I can't find anything by either of those users on that date, anyone else have better luck?

GLAD I HELPED
my post was in the original one...here is the link w/ pics
http://forums.bimmerforums.com/forum/showthread.php?t=674198&page=2&highlight=m60+oil+pan+bolts

I read both of those posts (and intend to drop my pan as well...) and got the impression that the bolt you speak of (looks like an inverted allen-head) was for the oil pump chain-tension adjustment. If that's what's broken on yours then you may have, in fact, gotten lucky.

I agree that if you did break off a rod bolt you'd have instant knocking and pretty immediate rod failure.

Update...

Just had the chance to get back under the car... after further investigation, it is not a connecting rod bolt that has sheared but a collar screw that supports the crankshaft. It has the same head as a connecting rod bolt only much larger. Thankfully, I was able to remove the broken bolt very easily!

The part number for the bolt is 11-11-1-741-294 (M10x100) - check realoem.com for illustration as I have no pics available...sorry!

Vehicle info - 95' 540iA/Prod date = 6/95

Does anyone know the Tq value for this/these bolts??? The dealers are very stingy about revealing this type of information!

onelivefive

How involved is it to take the pan down?? I plan on doing it as soon as possible. Thanks

Not difficult or involved...simply proceed as you normally would when changing your oil; once the old oil is drained, disconnect the oil level sensor connector/plug (it is the only electrical plug there), and remove the 20 or so 10mm hex bolts that secure the lower pan to the engine - remove the pan and investigate/repair/tighten as needed!

You can refer to the excellent posting and pics by 'gboezio' and shelbyz4u2nv [Jan 23, 07] to get a heads-up in terms of what you may (or may not) see once the pan is removed!!!

Be sure to install a new oil pan gasket!

Hope this helps!

Thank you very much. I am so happy i found this thread I had no idea the oil pump bolts were an issue. I am definitely going to check this out as soon as possible.
Thanks again!!