Broken fan blades make for idle vibration w/E300D - PeachParts Mercedes-Benz Forum

cewyattjr · #1 09-28-2013, 11:36 AM

This was a little surprising to me, but the physics of it make sense.

The back story is that I had my car ('99 E300D, W210) in the shop last week... evidently the fan shroud didn't get clipped in very well and when I started it the shroud was loose enough to fall into the moving fan.

Both of them are plastic and mostly just made a big racket. But then I noticed two blades had been broken off. I've now just pulled the whole shroud out.

Now at idle, you can feel a noticeable shake that feels like you are sitting in a massage chair. I am assuming this is a predictable result of the fan now being pretty severely out of balance.

I've ordered a new blade set from PeachParts. I assume the install should be a pretty simple wrenching, true? Do I really need the shrould?

I'll certainly mention it to my shop where I go, though they treat me well, so I don't want to really bust their b***s over it.

Thanks a lot!!

Chuck

compu_85 · #2 09-28-2013, 11:45 AM

I would remove the fan so you don't beat up the bearing on the water pump, or at the least break off the blades on the opposite side of the fan.

-J

cewyattjr · #3 09-28-2013, 12:02 PM

Wouldn't it overheat if I removed the fan entirely? Average temps this time of year are on the 60's though, I do mostly highway driving.

compu_85 · #4 09-28-2013, 12:51 PM

Then I'd break the blades off the opposite sides if you must drive the car. You don't want to ruin the bearing on the water pump.

rscurtis · #5 09-28-2013, 06:08 PM

Do I really need the shroud?

If you didn't, Mercedes wouldn't have installed it in the first place. You may be OK without it in most situations, but I would vote for replacement.

razvy · #6 09-29-2013, 07:24 AM

Chuck, the shroud makes the fan working properly , fan sucks air thru the radiator like a funel, whit shroud remouved driving in trafic in hot day you can overheat .

layback40 · #7 09-29-2013, 09:02 AM

i think if you broke 1/2 of one of your arms off, you would shake a bit, not just at idle !!

I would take the fan off for now. You will need to avoid sitting at the lights with the motor going. On the highway it will not be an issue.

vstech · #8 09-29-2013, 09:05 AM

the shroud is nigh critical. that motor makes some serious heat. I agree, if you MUST drive with the fan broken, gently saw off the blades on the opposite side, or treat the two broken blades as the base of a Y and clip two spanning the axis for better airflow
your blade should have had 11 blades, so removing two more would leave you with 7... not a lot, but it'll eleminate the vibration.

two things are causing the humm. one, the imbalance is causing the shake, but the buffeting from the gap in the wind, two the spacing is causing a harmonic that's noticed as well...

cewyattjr · #9 09-29-2013, 10:31 AM

Thanks guys. I took off the fan this AM, and am going to run an errand and see how it goes. I've ordered new blades but not the new shroud yet.

I know this repeats some info, but just for info purposes, I removed the cross beam above the radiator, once that was done, I could get just enough room in there to get in a ratchet with a 5mm male hex. Loosened up just enough to get in an allen wrench and did the rest by hand. There are 3 of those 5mm hex screws that hold on the fan, and you get to them at the front of that fan clutch.

The fan clutch seems pretty good, btw, not much play in the rotation.