How long can Engine last with a spun/damaged bearing?

[futron.sim]

I did something extremely stupid yesterday which result in possibly a spun/damaged bearing. When I was installing the oil filter, I did not fit the copper crush washer properly, causing oil to spray thru a tiny gap.

The problem is I didn't notice it till I was travelling and saw smoke coming out from my hood there is a distinct burnt smell. When I stop and checked, I realise the dip stick is literally dry! I

The problem now with the engine is that there is an occassional rattling noise. It happens only after I have travel for around 20-30min. When its cold, there is no noise. Is the noise cause by a spun bearing? I also get the burnt smell coming from my aircon once in a while.

The car seems to be running fine right now with new oil. However, how long can an engine last with damaged bearings if I maintain the engine properly? I am planning a full rebuilt at end of the year with new pistons/rods/crank, thus I don't need the current internals, only the block itself. Just hoping it will last till then.

[xwill112x]

it should maintain well for a long period of time, if the rattling gets worse..i'd just rebuild the motor to avoid any more damage.

[cecotto]

i would most definatly have the bearing changed asap.

Your crank might not be damaged as of yet, but with a noisy bearing it's just a matter of time.

Also you can pick a convinient time to do the rebuild.

[peerless]

Bad bearing will make noise all the time.

You have scared yourself because you lost some of your oil. And you most likely didn't even loose all of it. The dipstick only shows about 1.5-2 qts, your M42 takes 5.5 qts. So just because it doesn't show on the dipstick doesn't mean you fried your engine.

The rattling has probably always been there and you just now noticing it because your 'hyper sensitive' because of what happened. Probably just the normal chain rattle on high mileage M42's.

Regarding your crank, its probably already damaged anyways. These M42's have only 1/2 a thrust face bearing which does not provide enough support to the crankshaft. Every M42 crank I have seen has had more then normal wear on the thrust surface. 2 out of 4 M42s where scrap. and the 3rd out of 4 was just barely within tolerance. So basically don't worry about the crank, its probably already damaged.

One other thing, be very aware that the M42 is a very expensive engine to rebuild properly. I can build a 400HP 350 for the cost of a stock M42 rebuild. They are roughly about $2500-$3000 to do them right.

As a note, pay attention to what your doing next time you do a oil change. These are not kids lego's your playing with. Also please put add your location to your profile so people know where your at. If your in SoCal, I rebuild BMW engines.

[futron.sim]

i would most definatly have the bearing changed asap.

Your crank might not be damaged as of yet, but with a noisy bearing it's just a matter of time.

Also you can pick a convinient time to do the rebuild.

Actually I don't mind the crank being damaged. This is because I will be using a different crank when I rebuild the engine (going to use the 88mm diesel crank).

[Hondo]

Can the crank be machined for oversized bearings?

[peerless]

Can the crank be machined for oversized bearings?

Yes but its rather expensive. You turn down the journals as normal, then precision grind the thrust surfaces. Then the whole crank needs to be re-hardened.

It cost about $400. I know because I have done one.

And all of that is providing the thrust surface still has enough meat left. The one we pulled from a 93 E36 M42 was completely wasted and non-serviceable.

[colin86325]

Drain your oil and look for copper-colored flakes.

[futron.sim]

Bad bearing will make noise all the time.

You have scared yourself because you lost some of your oil. And you most likely didn't even loose all of it. The dipstick only shows about 1.5-2 qts, your M42 takes 5.5 qts. So just because it doesn't show on the dipstick doesn't mean you fried your engine.

The rattling has probably always been there and you just now noticing it because your 'hyper sensitive' because of what happened. Probably just the normal chain rattle on high mileage M42's.

Regarding your crank, its probably already damaged anyways. These M42's have only 1/2 a thrust face bearing which does not provide enough support to the crankshaft. Every M42 crank I have seen has had more then normal wear on the thrust surface. 2 out of 4 M42s where scrap. and the 3rd out of 4 was just barely within tolerance. So basically don't worry about the crank, its probably already damaged.

One other thing, be very aware that the M42 is a very expensive engine to rebuild properly. I can build a 400HP 350 for the cost of a stock M42 rebuild. They are roughly about $2500-$3000 to do them right.

As a note, pay attention to what your doing next time you do a oil change. These are not kids lego's your playing with. Also please put add your location to your profile so people know where your at. If your in SoCal, I rebuild BMW engines.

Thanks for the info. Unfortunately, I won't be able to get help from anyone in the forum. This is because I lived in Singapore.