Rod bearing replacement - UPDATE

Viren said:
FD3S said:
Before 3 days I have done my rod bearings replacements and changed also my mounts with Vibra Technics Road version. The car at cold start has vibrations and has no comparison with stock mounts. However within the first mile the vibration gets reduced and disappears. My car has idle at 950 rpms however. Also the car feels more robust on the gear changes but that can be also a placebo effect.
Click to expand...

So to be a little more clear sometimes when pulling away up hill if you don't give enough gas the revs drop a little and I feel a vibration throughout the car (the cars idle is perfect, no issue with that, just the vibrations). Also when pulling away like normal there is an initial virbration. It has been getting gradually worse and I've booked the car in to have it looked at. Will let you guys know what the problem is.
Click to expand...

The same applies for me. Below 750 rpm when I am in first gear I have noticeable vibrations. Also when the car is starting a cold start I have a slight vibration in the whole cabin. To be honest after the rod bearing replacement I have done only three runs with the car so I have to test it more so I can verify those situations.
 
FD3S said:
Viren said:
FD3S said:
Before 3 days I have done my rod bearings replacements and changed also my mounts with Vibra Technics Road version. The car at cold start has vibrations and has no comparison with stock mounts. However within the first mile the vibration gets reduced and disappears. My car has idle at 950 rpms however. Also the car feels more robust on the gear changes but that can be also a placebo effect.
Click to expand...

So to be a little more clear sometimes when pulling away up hill if you don't give enough gas the revs drop a little and I feel a vibration throughout the car (the cars idle is perfect, no issue with that, just the vibrations). Also when pulling away like normal there is an initial virbration. It has been getting gradually worse and I've booked the car in to have it looked at. Will let you guys know what the problem is.
Click to expand...

The same applies for me. Below 750 rpm when I am in first gear I have noticeable vibrations. Also when the car is starting a cold start I have a slight vibration in the whole cabin. To be honest after the rod bearing replacement I have done only three runs with the car so I have to test it more so I can verify those situations.
Click to expand...

That's interesting, where abouts are you based would be good to do a comparison if you want?
 
I think its just a trait of the mounts unfortunately quite a few on cutters have installed them and removed them due to vibrations maybe take a look on there :(
 
It's funny because the vibration has got progressively more noticeable. Normal driving it feels so tight nothing wrong. It's really only on idle and pulling away at low revs. I'll take a look on cutters as well
 
Viren said:
FD3S said:
Viren said:
So to be a little more clear sometimes when pulling away up hill if you don't give enough gas the revs drop a little and I feel a vibration throughout the car (the cars idle is perfect, no issue with that, just the vibrations). Also when pulling away like normal there is an initial virbration. It has been getting gradually worse and I've booked the car in to have it looked at. Will let you guys know what the problem is.
Click to expand...

The same applies for me. Below 750 rpm when I am in first gear I have noticeable vibrations. Also when the car is starting a cold start I have a slight vibration in the whole cabin. To be honest after the rod bearing replacement I have done only three runs with the car so I have to test it more so I can verify those situations.
Click to expand...

That's interesting, where abouts are you based would be good to do a comparison if you want?
Click to expand...

You are always welcome to come to Greece where my car is located to do the live comparison. :rofl: :rofl: :rofl:
I will watch how it goes within the next week and I will update you though.
 
:rofl:
Fair enough, that's a bit far! My cars going in to the mechanic on Tuesday so will also provide update after that.
 
An increase in NVH at idle is to be expected. The engine is more rigidly mounted, so more vibration is transmitted. This will be especially noticeable at the engine speed that matches the resonant frequency of the body shell.
I would expect a similar increase in vibration at multiples of that engine speed, but this is probably hidden by the noise and vibration generated by the car moving.
With the car in neutral, try to identify the exact rpm where the vibration is at its greatest, then raise the revs to multiples of that rpm with the car stationary. You'll likely find similar vibration at each multiple.
Of course, if it really is becoming more pronounced with use, it's worth checking the bolts are torqued correctly.
 
So seems like the reinforcement plate needed a little tightening but that's it. The vibrations have definitely decreased and all in all I'm loving it! Now I need to get past the running in period and oil change at 500 miles. Then good to go!
 
Nice to hear buddy glad it's all sorted.

You going for the 500 Mile oil change then and not the 1200 Miles?

Did they put fresh oil in when the did the bearings?

Mine are getting done one Thursday with new OEM Mounts and PAS hose.
 
hopz121 said:
Nice to hear buddy glad it's all sorted.

You going for the 500 Mile oil change then and not the 1200 Miles?

Did they put fresh oil in when the did the bearings?

Mine are getting done one Thursday with new OEM Mounts and PAS hose.
Click to expand...

I'm changing tge oil at 500 miles and yes the oil is completely drained when rod bearings are changed so fresh oil is part of the service. I've just been taking it easy keeping it below 4k rpm. Once the oil has been changed then I'll raise the revs. The main reason people breakin an engine is the seat the valves. However taking it easy after a rod bearings change is precautionary, theoretically speaking there is nothing to break in as the parts do not make contact. However it's seen as good practice.
 
Viren said:
hopz121 said:
Nice to hear buddy glad it's all sorted.

You going for the 500 Mile oil change then and not the 1200 Miles?

Did they put fresh oil in when the did the bearings?

Mine are getting done one Thursday with new OEM Mounts and PAS hose.
Click to expand...

I'm changing tge oil at 500 miles and yes the oil is completely drained when rod bearings are changed so fresh oil is part of the service. I've just been taking it easy keeping it below 4k rpm. Once the oil has been changed then I'll raise the revs. The main reason people breakin an engine is the seat the valves. However taking it easy after a rod bearings change is precautionary, theoretically speaking there is nothing to break in as the parts do not make contact. However it's seen as good practice.
Click to expand...

Is that what CPC recommends, changing oil 500 miles later?
 
Cpc said it should be okay to not change the oil as they ultrasonic clean the sump and other bits however for what it costs there can't be any harm. They change lots of rod bearings so would listen to their opinion but like i said if any bearing bits have rubbed of or if there is any dirt which made its way into the bottom end while it was all apart, I think a oil change seems reasonable. 500 miles is my own decision based on what I've read. 1200 miles is more for new engines or full engine builds.
 
Thanks for the reply. Are you local to them? I'm only 10 miles up the Chesham road, would be good to meet for a chat if you're close by.
 
bmwaddict said:
Thanks for the reply. Are you local to them? I'm only 10 miles up the Chesham road, would be good to meet for a chat if you're close by.
Click to expand...

Sure bud. I'm in edgware so not far. Drop me a pm and we can organise a meet.
 
50k miles/80k km

So if a rod bearing replacement repair costs £1000 its an added 0,02ct/mile or 0,0125ct/km running cost.
 
How is the running in going OP?

I have managed 40 miles so far so this could take a while.... I am finding it very boring that's for sure.

Ash
 
You must log in or register to reply here.
Back
Top Bottom