Excessive Engine Movement

[Rek]

I have what appears to be excessive engine movement. This translates to movement at the guibo when accelerating in first gear - although I have not been able to verify this is the cause.

I have a B34 engine installed from a 535i E34 (Alpina B10). Which engine mounts have people used when replacing the engine? The original E9 ones or the E34 mounts?

I will check for tightness but cannot see much movement. Also - the mounts may be after market parts. Has anyone had experience of such and are their inferior products out there? I was thinking that the rubber might be softer or something similar.

Normal driving seems fine, but too much revs in first and the drive train vibrates.

 

[lloyd]

I have what appears to be excessive engine movement. This translates to movement at the guibo when accelerating in first gear - although I have not been able to verify this is the cause.

I have a B34 engine installed from a 535i E34 (Alpina B10). Which engine mounts have people used when replacing the engine? The original E9 ones or the E34 mounts?

I will check for tightness but cannot see much movement. Also - the mounts may be after market parts. Has anyone had experience of such and are their inferior products out there? I was thinking that the rubber might be softer or something similar.

Normal driving seems fine, but too much revs in first and the drive train vibrates.

Although I suspect that the newer mounts would incorporate certain improvements over the older style mounts, your issue begs another question: What is the condition of the mount (or mounts) on your transmission cross member? Whatever type of cross member and mount or mounts, if in bad shape, it /they will permit and/or contribute to the "unwanted" movement you suspect to be at the root of your problem. The cross member/transmission mount may also alter drive shaft alignment.

 

[teahead]

Driveline/shaft angle?

 

[teahead]

Rev in neutral.... Vibrates?

 

[bert35csi]

With this condition, watch out for sudden braking as the engine can lurch forward and smash into the radiator with the fan/clutch assembly. Been there.

 

[Rek]

Thanks for this. I will get the car on a lift and inspect the engine and transmission mountings. They were all replaced, but I think they might be substandard aftermarket items rather than the originals.

The engine does move a lot regardless of transmission movement, so engine mounts are first, then the transmission. I will also try to revving in neutral. I do believe there is vibration. It is certainly not the smooth drive train I would expect from a BMW.

 

[sfdon]

All 3 rubber mounts together are under 25 dollars us.
Just replace them if you are worried.
If it doesn’t exhibit the problem at idle or reving but not in gear it’s behind the tranny that is where you should be looking I think.

https://www.rmeuropean.com/Make/PartNumberSearch.aspx?pnsearch=11811132322

https://www.rmeuropean.com/Products/23711175424-MFG253-V147.aspx

 

[sfdon]

BTW- no b34 engines came from e34 cars. E34 has the b35 Engine.
Different intake valves, ports, oil chain tensioner, pistons....

You need to post a pic of your tranny output - which tranny, guibo and whether it has a manual or automatic driveshaft. The drive shaft noses are different and if you installed an auto driveshaft into a manual with a later guibo it will shake.

 

[Rek]

Thanks, I will take some pictures and post them. I will also video the engine movement.

I used the drive shaft which was on the car, but the bearing mounts did not line up with the brackets on the body so it might have been a replacement. Its a manual car with the original 4 speed transmission.

Noted on the B34 - its the 3430 cc version.

 

[Ohmess]

Look too at your tranny mount where it is bolted to the body of the car. I was concerned about how close the T bolt that fits into the body came to the opening in the steel runner that holds the bolts on my car. If the bolt aligns with that opening, it will not hold the tranny in place.

Because of this concern, I replaced the tranny mount I had with the one that Coupe King sells. http://www.coupeking.com/shop/product/e9-5-speed-conversion-mount-kit/

Pricey, but very robust.

 

[inovermyhead]

Rek, I too have been going through this problem, mine will make some load banging noises when under reasonably hard acceleration in first gear or pulling away on a hill start. It is not across the board as I have tracked the car and it will pull hard in higher gears but in first you have to be a little gentle and feed the power in.
I have been through all the usual suspects and am fairly convinced the problem lies with the engine mounts being too soft and allowing the engine to twist under load.
There is a company in the UK that makes engine and transmission mounts that are machined from aluminium with rubber inserts and the e30 m3 model is the one you want, sorry can’t remember the name of the company, that’s the way I’m going to go.

John

 

[Ohmess]

Guys -- with our cars, I would stick to rubber bushings. While other materials might hold the engine or tranny in tighter to the body, they will transfer more load into the body of the car. And the body of our cars is held together with spot welds.

I know with newer cars going stiffer is better, but I worry about the ability of our cars to handle the stresses. A friend of mine totaled a coupe on the track going off and bottoming out -- stress fractures in the body of the car.

 

[sfdon]

Rek, I too have been going through this problem, mine will make some load banging noises when under reasonably hard acceleration in first gear or pulling away on a hill start. It is not across the board as I have tracked the car and it will pull hard in higher gears but in first you have to be a little gentle and feed the power in.
I have been through all the usual suspects and am fairly convinced the problem lies with the engine mounts being too soft and allowing the engine to twist under load.
There is a company in the UK that makes engine and transmission mounts that are machined from aluminium with rubber inserts and the e30 m3 model is the one you want, sorry can’t remember the name of the company, that’s the way I’m going to go.

John

Bad center bearing or on backwards...

 

[aearch]

no brainer

 

[aearch]

move shake it around by hand

 

[inovermyhead]

Ohmess I hear what you are saying and agree that the coupe body shell is inherently weak in comparison with a modern... but, what about the stress of an engine twisting under load, surely that’s going to cause a problem?

Don, we have done this dance before, the center bearing is new, the right way round and preloaded, the prop is balanced, the transmission mounts are new, the guibo is new, the diff mount has been reinforced, the cross member is new AND it only happens in first from stand still....

Alan WTF does ‘no brainer ‘ mean

 

[Rek]

My centre bearing is new as is the guibo and gearbox mounts. Mine only happens in first too, and only really from a standstill.

I am not going to differ from the rubber mounts as this is how it was designed and they should work well. I do wonder whether the E34 mounts or the E9 mounts should be used. I currently have E34 mounts, but the engine should not move as much as it does. Its not meant to move that much and BMW's are noted for their smooth drive train.

More investigating to be done. First will be to take a look at engine movement on other E9 and E34 cars and compare these with mine.

I will let you know what I find.

 

[inovermyhead]

Rek, I have a b35 from an e34 and used new mounts for an e9, been chasing this problem for some time, obviously I have no brain.

 

[sfdon]

Ohmess I hear what you are saying and agree that the coupe body shell is inherently weak in comparison with a modern... but, what about the stress of an engine twisting under load, surely that’s going to cause a problem?

Don, we have done this dance before, the center bearing is new, the right way round and preloaded, the prop is balanced, the transmission mounts are new, the guibo is new, the diff mount has been reinforced, the cross member is new AND it only happens in first from stand still....

Alan WTF does ‘no brainer ‘ mean

Febi or Rhein centerbearing?

 

[Stevehose]

Did you align your driveshaft to mate flush with the tranny flange? If it is off then all new components could still vibrate as you describe. Loosen the tranny flange/driveshaft bolts so there is about 1/8" gap, then rotate the driveshaft, if the distance closes or opens between the two surfaces you need to adjust the up and down or side to side position (or both) of the center bearing mount so that no wobble is present. You may need to add washers or enlarge the bearing mount slots to allow for more adjustments. A little goes a long way. Then tighten the tranny flange back up to the D/S.