Front fan blades blocked and not turning... can this ruin the engine when run? - PeachParts Mercedes-Benz Forum

DieselPop · #1 03-20-2011, 03:06 PM

I was recently in an accident where the front of my 300D was smashed up. The brunt of the damange was absorbed by the hood crunching into a rear-tire mount on a small SUV, but this also did push in the front elements around the radiator and lights some. It looks almost normal with a junkyard hood replacement put on, but the mount-latch does not match up and I have to wire the hood down to drive.

I found on closer inspection that the radiator and associated body frame where it mounts were pushed back enough where the fan is just slightly blocked from turning behind the radiator. Amazingly the radiator was not punctured and there were no fluid leaks. I was so bummed with the whole deal that I drove the short distance home after the accident. The car has been driveable on a few short hops and I did not notice any increase in normal operating temperatures on the gauge on the dash.

So.. it seems like the engine can run OK with the the fan blocked, at least for short distances. It must be on some kind of internal clutch system? What are the consequences of driving it like this until I can get the radiator and front area pulled out (if at all possible?). Could I be doing some serious damage here? I haven't driven very much at all with it like this, but I do need to be able to drive it again soon on longer trips.

Thanks All.

wildest · #2 03-20-2011, 03:20 PM

If the fan is locked while the motor is running, it is a just a matter of time till the fan clutch really locks up/comes apart. I wouldn't risk it short of a serious emergency.

vstech · #3 03-20-2011, 03:26 PM

the fan not turning likely damaged the clutch. I'd certainly replace the clutch once you are ready to drive the car again. (after you fix the radiator support)

leathermang · #4 03-20-2011, 04:03 PM

Quote:

Originally Posted by vstech

the fan not turning likely damaged the clutch. I'd certainly replace the clutch once you are ready to drive the car again. (after you fix the radiator support)

Justs something else to keep in mind... like when you can not go to sleep at night...
MB specifies that that replacement fan clutch be stored in the vertical position on the shelf....
Try being sure your replacement was not laying down flat... LOL

DieselPop · #5 03-20-2011, 05:50 PM

In regards to the "Wildest" post....

Since it would be bad if the fan clutch locks up while blocked like that, what if I could manage to undo and take off the fan so that at least the axle it is mounted on can turn freely?

Thanks for all the input... I'm somewhat in alarm mode now... have to get the rad pulled out soon. Would be nice to have it safely mobile though so that I can at least drive it to some body shops to get bids on pulling out the radiator area.

leathermang · #6 03-20-2011, 06:01 PM

You should be in somewhat alarm mode.... so that is good..
do you have aux fans in front of your radiator ?
If so, can you run them all the time you have the car running ?

aaa · #7 03-20-2011, 06:05 PM

Quote:

Originally Posted by DieselPop

Could I be doing some serious damage here?

Main risk is doing your radiator in. When you take the fan off, put some washers or something on the fan bolts, I don't think they go in deep enough to hold the pulley snug without the fan being there. Belts flying off = instant overheat. Don't ask how I know.

t walgamuth · #8 03-20-2011, 06:26 PM

If it were mine I would pull out the rad and try to straighten the rad supports enough to get the hood to latch, reinstall the rad taking care to be sure the mounts are matching up to the rather fragile radiator cleanly. ONce all that was squared away I would move the fan blade around and see if it feels normal....will move, will not wobble, moves with some resistance but not too much. Then if it pases all those tests I would try driving the car and see if it cools properly.

You might get lucky and have no serious damage once you get it all straightened out.

Stretch · #9 03-21-2011, 04:41 AM

Dieselpop do you live in a warm climate? Do you sit in traffic a lot?

If not then I'd say try driving about with out a fan! I've done so on my 300D with out any (over heating) trouble.

The thing to remember is that most of the year the temperatures where I live are under 20 degrees C... to me the fan is just a big old lump of junk that doesn't do any good for most of the time.

This subject can cause a lot of emotional responses - mainly from kind people who feel that I'll get stuck in a desert somewhere - but the nearest desert to where I live is probably a good 3 or 4 days solid drive away...

http://www.peachparts.com/shopforum/showthread.php?t=264626

josha37 · #10 03-21-2011, 01:18 PM

Army i pulled my fan to but i ran the aux fan on the front to a switch, might be something for you to consider?

Stretch · #11 03-21-2011, 02:06 PM

Quote:

Originally Posted by josha37

Army i pulled my fan to but i ran the aux fan on the front to a switch, might be something for you to consider?

Thanks for the tip but my Euro 300D doesn't have any air conditioning or extra fans as standard. If you look towards the end of the thread I posted above you'll see an electric aftermarket fan that I bought for our summer trips down to the South of France.