SLK 350 Noisy heater blower motor removal?

[Colin_b]

The blower has become noisy, sounds like a dry bearing. The vents/drains are all clear, and no error codes registered, so it sound like the motor needs a clean and lubricate.

So, how do I remove the motor - seems to be stuff saying it's easy or hard, depending where you look!

Anyone any experience?

 

[Colin_b]

As no one seems to know

Car is a 2007 SLK350 R171 and the problem was a noisy heater fan, squeaking, rattling and grating. Appeared suddenly.

Here's how I did it....

You need a T20 torx driver, and a couple of smallish screwdrivers and a piece of wood about 18" long.

First remove 3 x T20 screws holding the plastic cover under the glovebox (I'm assuming RHD by the way..), and drip the cover a bit.

Remove the connector for the interior light and fag lighter, the latter being a bit fiddly, you flip a catch to release the connector. Now remove the cover.

Next remove the pollen filter, its in the cover to the transmission side of the fan, and the cover is held on my 2 x slide clips.

Remove the fan housing, 3 x T20 screws, 2 fairly well concealed, you'll need to get your head inside the footwell. Hold the assembly and now remove 1 x electrical connection ans one junction cliped to the side of the housing. A small screwdriver to release the clips to unclip. Then out with the fan.

The inside of the fan housing was slightly water stained, though the drainage wasn't blocked (I check regularly). No signs at all of dampness, the pollen filter showed no sign of water staining.

To remove the fan from the housing... Remove 2 x T20 screws holding the control unit in place, then place the unit fan down and you'll see 3 rubber grommets which hold the fan and motor in place.

With a small screwdriver push these 3 grommets through the housing to release the fan. Carefully remove the fan and motor with the control unit, and disconnect the control unit.

The fan was running rough, the bearings were squeaky and there was a fair amount of end float which had allowed the fan to rub against the housing.

The noise appears to be a combination of dry bearings and fan/housing contact. Probably terminal, but a combination of wd40 and 3 in 1 oil at least made the fan spin quietly and relatively easily.

The bottom of the fan had signs of water damage, obviously spent some time immersed in water, but not much, there was only light surface rust.

So, reassemble and check results...

Put the fan/motor back in the housing. Put a little washing up liquid on the top of the grommets to make their pulling through the housing, then reassemble reversing the above. The bit of wood is useful to hold the housing in place while you replace the screws...

But...check you don't lose the clips that hold the pollen filter in place, they appear to jump off with gay abandon.

All in all, a fairly easy job, but quite fiddly

When it was back together, the fan was quieter, the bearing noise has gone, but the fan/housing noise is still present. So partial success and I'll need to replace the fan. Ho hum.

 

[Colin_b]

To complete, new motor and pollen filter installed. Parts £250, took about 45 mins after last weeks practice.

And works as designed again.

New front disks and pads are next, when we get a dry weekend...

 

[dermots]

To complete, new motor and pollen filter installed. Parts £250, took about 45 mins after last weeks practice.

And works as designed again.

Thanks for your instructions further up - I used them to remove the noisy blower in my SLK R171 and oil the thing, but I didn't expect it to last long and it has since stopped working.

I appreciate it is 3 years since you replaced yours, but would you have any advice on where to buy the parts? Cheers.

 

[Colin_b]

Thanks for your instructions further up - I used them to remove the noisy blower in my SLK R171 and oil the thing, but I didn't expect it to last long and it has since stopped working.

I appreciate it is 3 years since you replaced yours, but would you have any advice on where to buy the parts? Cheers.

Sorry for the delay... As far as I remember I got a genuine MB part from a UK dealer via Ebay (about £30 cheaper than the parts dept at my local dealer).

This is an example..
Genuine Mercedes-Benz R171 SLK Heater Blower Motor A1718350104 NEW | eBay

There are some cheaper pattern ones, but they look like the older SLK r170 version.

Have fun

 

[dermots]

Sorry for the delay... As far as I remember I got a genuine MB part from a UK dealer via Ebay (about £30 cheaper than the parts dept at my local dealer).

This is an example..
Genuine Mercedes-Benz R171 SLK Heater Blower Motor A1718350104 NEW | eBay

There are some cheaper pattern ones, but they look like the older SLK r170 version.

Have fun

Having since had the old fan assembly completely to pieces it is definitely non-repairable. I ordered the genuine MB part - all others were LHD - also at a slight discount from list as you did (£240 vs £265 dealer list). The secondary market LHD fans can be made to work RHD in the old fan casing (reverse motor polarity, reverse fan blades) but the old casing was in a bit of a state after wear from the old fan so I decided against it; reversing the fan blades also seemed to be a bit tricky.

I'll be fitting the new one this weekend if I have time. I opted for a new regulator too, £35 on Amazon against £260 from MB...

I bought the fan at Mercedes-Benz Parts, Inchcape which sounds quite a spammy URL (mercedes-benz-parts dot co dot uk) but in fact is MB of Oxford.

 

[dermots]

I'll be fitting the new one this weekend if I have time. I opted for a new regulator too, £35 on Amazon against £260 from MB...

All fitted successfully and I now have a quiet, efficient blower again.

The new regulator simply didn't work. With it in place the fan operated at full speed unconditionally - with the ignition off!!! It nearly took my fingers off when I plugged it all together. Although the old regulator looks like it has been sat in a bucket of rusty water it is working well. The "new" regulator was sent back for a refund as being either broken or incompatible.

Thanks again for the info above which gave me the knowledge to take on this task. I know it's hardly an engine rebuild, but the steps above turned a 4 hour job into a 1 hour job.

 

[Colin_b]

All fitted successfully and I now have a quiet, efficient blower again.

The new regulator simply didn't work. With it in place the fan operated at full speed unconditionally - with the ignition off!!! It nearly took my fingers off when I plugged it all together. Although the old regulator looks like it has been sat in a bucket of rusty water it is working well. The "new" regulator was sent back for a refund as being either broken or incompatible.

Thanks again for the info above which gave me the knowledge to take on this task. I know it's hardly an engine rebuild, but the steps above turned a 4 hour job into a 1 hour job.

Glad it's OK Just check the drain tubes are kept clear - particularly after autumn when dead leaves turn into stoppers...

 

[K80NBM]

Hi these heater blowers seem to break regularly due to water ingress from the water gulleys drain hole under the windscreen getting blocked with leaves etc and overflowing into the under glove compartment area housing the blower motor.

A lot cheaper to buy second hand blowers and reguators from eBay for around £45. If they go wrong again, not so painful..