Replace rod bearings w/motor in car?

[DeeJayDubbuyew]

Is this worth trying? Or do you just have to pull the motor?





You know what'll happen if I get the motor on the stand... :) $ :)

[SpecM]

-You can, but It'll be a pain-in-the-butt. You'd still have to remove the head, and the crank. Remember to replace the rod bolts too!

[peerless]

You can do it. If you have a lift it would be a ton easier. As a note you do not have to remove the crank from the engine to do rod bearings. You will need new bod bolts. About $55.

You also don't have to remove the head or the pistons.

But I do ask

'Are you sure your bearings are bad?'

What are the symptoms?

[DeeJayDubbuyew]

It knocks at 2500+ rpms, & the first few revolutions on a cold start, b4 oil pressure builds. It runs very well & only seems to be one rod. I've inspected the rockers & all seems good there. The car has 190k on the clock.
Gaining access to the rod bolts is all I need. So I need to raise the motor & pull the pan, or do you drop out the cross member?

[ieatpeople]

It knocks at 2500+ rpms, & the first few revolutions on a cold start, b4 oil pressure builds. It runs very well & only seems to be one rod.

i have an identical problem with my 87 325is, if that is fixable without swapping engines, or complete removal, that would be awesome.

[Eric Giles]

I replaced the rod bearings on my E30 M3 with the motor in the car, but I was also in the process of replacing the front subframe so it made the process much easier. I used one of those engine hoists that sits between the channels on the front fender and holds the engine via chain on the front pickup point, then dropped all of the front suspension and subframe. You can do it with the subframe in the car, but you will have a much tighter area to work in. Due to the fact it can be a pain reinstalling the oil pan/oil pump assembly on an M20, I would probably remove the front subframe to make the entire process easier.

[erik325i]

-You'd still have to remove the head, and the crank. Remember to replace the rod bolts too!

You do not even have to touch the head. You don't have to remove the crank either. I replaced my rod bearings in my m20 while in the car. I dropped the whole front subframe for easier access.

Erik

[jlevie]

As stated above, this isn't all that difficult to do w/o pulling the engine. An engine brace makes it easier and you will want to drop the sub-frame.

[DeeJayDubbuyew]

You do not even have to touch the head. You don't have to remove the crank either.

Erik

Yeah, I knew all that - I just need to be able to remove the pan, rotate the crank & have access to the rod bolts.

It looks like you could leave the struts attached at the top, remove the 4 big bolts & just drop (not remove) the sub-frame. Am I missing anything? Steering column-to-rack connection? Brake lines?
Maybe two hours & I could have the pan removed?

[SpecM]

You do not even have to touch the head. You don't have to remove the crank either. I replaced my rod bearings in my m20 while in the car. I dropped the whole front subframe for easier access.

Erik

-Yea you're right, I wasn't thinking about it correctly... nevermind...

[kenika65]

Here there are some picture to help you visualize it.

And I know you have an M20!

http://www.r3vlimited.com/board/showthread.php?t=114492