E90 170k rod bearing question

[pbonsalb]

But coils may be more critical on the S65 because knock control is done through the plugs. I would like to know more about the role of the coils in that and whether added resistance and/or weaker coils due to age or heat or use/mileage has any effect.

[randrews15]

Originally Posted by Ximian

Have you seen the price of ignition coils? Complete waste of money if they are working properly. Since they're easy enough to replace, it doesn't make sense to do them preemptively. These aren't broken N54 engines that are constantly fouling up spark plugs and ignition coils.

I'm well aware of the cost of coils. It's about preventative maintenance. The key word here is preventing a problem before one. If they are original coils they one can likely assume that they are at the end of their service life at that mileage. If you're driving an M you better be able to afford some preventative maintenance, but you may not understand that and want to cut corners.

[Ximian]

Originally Posted by randrews15

I'm well aware of the cost of coils. It's about preventative maintenance. The key word here is preventing a problem before one. If they are original coils they one can likely assume that they are at the end of their service life at that mileage. If you're driving an M you better be able to afford some preventative maintenance, but you may not understand that and want to cut corners.

My eyes have rolled all the way to the back of my head. Can you help by searching for a fix? Preferably something cheap. Thanks!

The car has 170k miles on it. I doubt ignition coils are going to be the cause of whatever catastrophic failure occurs on it.

[randrews15]

Originally Posted by Ximian

My eyes have rolled all the way to the back of my head. Can you help by searching for a fix? Preferably something cheap. Thanks!

The car has 170k miles on it. I doubt ignition coils are going to be the cause of whatever catastrophic failure occurs on it.

Keep em rolling buddy and go troll somewhere else. You obviously don't understand mechanics of a car and not every failure is catastrophic. Just sit in the corner and be quiet now.

[randrews15]

Originally Posted by pbonsalb

But coils may be more critical on the S65 because knock control is done through the plugs. I would like to know more about the role of the coils in that and whether added resistance and/or weaker coils due to age or heat or use/mileage has any effect.

Certainly, if after 170k miles of use, if the original coils, they would have wear and tear from use and repeated heating and cooling cycles. If I remember correctly, the OP stated there was a low rpm issue which coils can contribute to as weak spark can cause this. Every used car in buy gets a tune up and every maintenance item addressed to ensure longevity. To date, I haven't had a catastrophic failure and all of them are going strong. This car may have a long life ahead of it since my first 3 series was well over 300k when I sold it.

[bmwpower603]

For the spark plug job.

Is the 16mm spark plug socket available at Harbor Freight/ auto parts stores?

Or is that something I should order from ECS tuning?

I have a receipt receipt from bmw. Stating that the car needs plugs. That was at 173k.

Definitely will be doing coils. But would like to try doing plugs first.

[randrews15]

Originally Posted by bmwpower603

For the spark plug job.

Is the 16mm spark plug socket available at Harbor Freight/ auto parts stores?

Or is that something I should order from ECS tuning?

I have a receipt receipt from bmw. Stating that the car needs plugs. That was at 173k.

Definitely will be doing coils. But would like to try doing plugs first.

If memory serves be correct, it was just the standard spark plug socket. It's not like the special one on a N55 motor or anything. I'd order one with a flexible head and plenty of extensions. The back cylinders are tricky but can be done with patience. You can order them anywhere you want as they're all the same.

[pbonsalb]

If you are doing plugs and plan on doing coils soon, I would do both at the same time so you do not repeat most of the labor. As suggested above, have a few extension options so you can fit rears where clearance is tighter. If you do not have a rubber lined plug socket that grips the plug, a magnet stick will help you pull the plug out of the hole. The coil tops can break if you are not careful and even when you pull them out. They are hollow plastic and can’t take much prying. There are various tricks people use and one person even designed a special tool just for these coils though I have one and don’t think it is that great.

[Scharbag]

I have found the bent coat hanger method works the best for getting the coils out. I also find that twisting them all a little before pulling helps. I find that getting the PS reservoir out of the way helps - and you of course have to remove the air-box. No need to remove the plenum.

And as pbonsalb implied, it is much easier with a good plug socket. 6 of the 8 plugs are easy. The back 2 can be entertaining but for a V8 in a small car, it is really quite easy to do.

[bmwpower603]

Here’s what the rod bearings looked like!

172k. Dealer maintained. Oil changes done when OBC recommended.

[LeeMT]

holy..... it's good to know you replaced them...

[s14_kev]

You did the right thing replacing the bearings, hats off to you. I'm not surprised at the condition given the mileage, but that is definitely NOT normal bearing wear.

[bmwpower603]

Originally Posted by s14_kev

You did the right thing replacing the bearings, hats off to you. I'm not surprised at the condition given the mileage, but that is definitely NOT normal bearing wear.

Yeah the owner said that’s abnormal wear lol

I’m glad it’s done. Hopefully I can run it until 250k before a rebuild.

Also, should I be keeping the RPM under 3k?

Atleast until I do the o2 sensors and plugs ?

I need an alignment and then diagnose the rear and sway when turning left only

[SoCalRPM]

Originally Posted by bmwpower603

Yeah the owner said that's abnormal wear lol

I'm glad it's done. Hopefully I can run it until 250k before a rebuild.

Also, should I be keeping the RPM under 3k?

Atleast until I do the o2 sensors and plugs ?

I need an alignment and then diagnose the rear and sway when turning left only

There shouldn't be any need for a break-in period with new bearings. In general though, as good practice I think most follow the following warmup procedure:

1.) Start the car and allow cold start cycle to finish, it's only about a minute.

2.) Begin driving as normal but don't push the car crazy hard or anything and keep the revs to about 3k RPM until the engine temp. needle hits that first indicator dot, which is appx. 165 degrees.

3.) You can then gradually increase revs up to 4K and 5k RPM and so on as the engine temp nears full operating temp of appx. 210 degrees.

4.) Once the car is up to full temp - Fire at will and enjoy!

Yes, this is a little absurd but this will allow time for the super thick 10W-60 oil to properly works its way through the engine to achieve sufficient lubrication hopefully without causing any damage or premature wear along the way.

[SoCalRPM]

And WOOF those bearings looked bad. You did the right thing.

[bmwpower603]

I’m so happy to have done this.

The car is amazing. And real M motorsport. Unlike the new m3 and m4. Which have same internals as the 340s, just beefed up.

It was either this. Or an e36 m3.. I say this

[8500RPM]

Originally Posted by bmwpower603

I’m so happy to have done this.

The car is amazing. And real M motorsport. Unlike the new m3 and m4. Which have same internals as the 340s, just beefed up.

It was either this. Or an e36 m3.. I say this

For sure the E60 M5 and E92 M3 are the real motor sports experience. I remember my 1st test drive in my car before I bought it. With test pipes and OEM exhaust mod I was sold. These cars have such a soul you can feel it. They love when you push them hard. Way more pleasurable than my old LS3 vette.

[TrAcK TRaP]

I don't remember anyone saying woww those RB's are still in good condition even with 35K miles vehicle

[pbonsalb]

There have been a few cars with good looking bearings. I’d put it at maybe 10%. Some were low mileage and some were higher mileage. But 90% show wear that is way beyond what wear should be for the mileage.

[Helmsman]

OP, thanks for sharing! Good sign that the bearing can wear and tear for a long time before they potentially go boom.

Would you mind posting here as well mate: https://www.m3post.com/forums/showth...253084&page=51

Thx

[XKxRome0ox]

Originally Posted by randrews15

my first 3 series was well over 300k when I sold it.

which 3 series was it and how much did you end up selling it for with 300k+ miles???

[randrews15]

Originally Posted by XKxRome0ox

which 3 series was it and how much did you end up selling it for with 300k+ miles???

It was a 1982 318i coupe. If memory serves me right I believe I got $1000 for it when I sold it.