E36 M3 Fan Blade Issue

[BMW4LIFE]

Has anyone had any issues with there fan blade hitting the shroud and breaking off the fins on hard cornering at the track? I searched this issue and found nothing.

My car has 130K miles.

It has happened to me twice now. My mechanic told me that the stock motor mounts are in good condition.

Do I need to upgrade to race mounts?

[jayhudson]

Is it possible the shroud is moving?

I wonder how your mechanic checked out the motor mounts? I'd be doing some checking myself.

Jay

[Michael9218]

Remove the fan, it robs you of horsepower anyway...

[GOTX]

Remove the fan, it robs you of horsepower anyway...

Maybe 3 or 4, big deal. Better to have the fan for a hot day. Many a driver has grenaded a motor forgetting to turn on his electric fan in the paddock on a 100 degree day.

Keep the engine fan.

[BMWALDO]

Keep the engine fan and upgrade the motor mounts. One of those "wow" maintenance upgrades.

I personally went with the Vorshlag Nylon mounts. I think the red Polyurethane would be a great upgrade that has little to no NVH.

[MikeE36]

Has anyone had any issues with there fan blade hitting the shroud and breaking off the fins on hard cornering at the track? I searched this issue and found nothing.

My car has 130K miles.

It has happened to me twice now. My mechanic told me that the stock motor mounts are in good condition.

Do I need to upgrade to race mounts?

Also check to make sure the little tab that holds the coolant line near the top of the fan shroud isn't broken off causing the line to touch the fan blades. This happened to me at the track. I would double check your engine mounts, mine needed replacing also, that's when I ate a 2nd fan... or maybe that was the 3rd...

[Boro]

I ruined 2 fans due to a failing water pump front bearing which then, subsequently, developed a leak. (Metal impeller pump)
Incidentally, I have been running my car without any fan for 3 years w/o any problems. My son's 95 M3 is street driven and has seen 90+deg heat all summer without a fan, again w/o any problems. (his car still has the aux fan which kicks in occasionally, my track car has no fan at all). I am not aware of anyone that has fried a motor with a "fan delete" but I shut it down if we are sitting in the pits for any length of time. YMMV
I would also replace the motor mounts (as already suggested), and probably tranny mounts if they are the original parts.
Hope that helps,
Tom

[magnetic1]

Id double check the motor mounts. I use stock rubber and have no issues.

[SportEvo]

I saw this happen just the other day. Seems stiffer motor mounts might be called for.

[NeilM]

Three (Edit: OK, so I can't count, make that four!) things to check, in order of likelihood (IMO):

1) Water pump shaft end-play. When the bearing fails this can allow the fan to touch the radiator.

2) Motor mounts. I too wonder how your mechanic checked them, since their rubber part isn't really visible when installed. And if you take them out to check, you might as well replace them anyhow.

3) Radiator shroud, hoses and related parts are all securely attached.

4) The front subframe where the motor mount lower studs attach. This is a known weak spot where I've personally seen a securely bolted motor mount lift right off, complete with the broken bit of subframe it was still attached to. Turner sells weld-in reinforcements, or you can use scrap metal.

If all these are as they should be then nothing should touch, even under track use.

Neil

[BMW4LIFE]

Thank you all for your suggestions and advice.

I think I will replace the motor mounts with something that is track worthy but does not effect the NVH.

Anyone other than BMWALDO have experience with the Vorshlag mounts? Any other companies have race mounts that I should take a look at as well?

Thank you!

[Michael9218]

I'd try someones "race" mounts out first. I have UUC race mounts and you will not like the vibration if you drive the car on the street. I could be that the mounts are worn and are the cause of the fan hitting the shroud. You may want to stick with stock mounts as a replacement.

I would still remove the fan. You have the auxiliary fan that will kick in if the motor gets hot. You can also buy an 80 degree celsius switch for the aux fan. The frying your motor comment was from someone who removed both the belt fan and the auto aux fan and was relying on a manually switched fan.

[cosmom3]

This has happened to me twice, and I finally upgraded to Poly engine mounts a couple months ago.

[BMWALDO]

Thank you all for your suggestions and advice.

I think I will replace the motor mounts with something that is track worthy but does not effect the NVH.

Anyone other than BMWALDO have experience with the Vorshlag mounts? Any other companies have race mounts that I should take a look at as well?

Thank you!

Some people commented in this thread:

http://forums.bimmerforums.com/forum...d.php?t=773326

[CABimmer]

I have nylon Vorshlag mount. Have had them on for a long time. I was one of the beta cars. They only really creat NVH just off idle. It is a non issue for a track car, but for a street car it may not be all that great, but its not that bad. These make a huge change to how your car handles when you shift. Total no brainer in my opinion.

I still drive mine to and from the track and it is not a race car, just track car. I dont even notice the NVH anymore.

[Erik L]

we used to check motor mounts on V8 domestics by idling the car, pop hte hood and rev it up. If it comes up more than 6 inches you need new mounts :-)

I think it only really checks one side though....