Shagged Hedgehog E46

[RanchoGrande]

I think my FSU hedgehog thing is shagged as the fan sometimes doesn't blow any air - doesn't seem to be a pattern to it though so I'm guessing the FSU is on it's way out.

I changed the FSU myself when it went on an old E36 but having looked at some guides on changing it on an E46 it looks a bit trickier. Has anyone here done it themselves or is this a job for the garage?

thanks in advance

[verbarthe]

I did this on my last E46. It s quite an awkward job to do unless you re a double jointed dwarf, (no offence to dwarfs double jointed or otherwise) I got a row from the wife for swearing in front of the grandchildren as there was quite a few choice expletives emanating from me that afternoon. Basically you have to lie on your back in the drivers foot well and reach up .There are a few How To s online , Google is your friend .
There is an alternative to this although I did nt do it this way myself but had I known of it I would have done it this way and that is to simply disconnect the wires from the old Hedgehog and reconnect them to the new one leaving the new hedgehog inside the centre console tunnel for easy future access instead of putting back into the most awkward , inaccessible place Bmw could have put it . . You pays your money and you takes your choice. Good luck .

[to3m]

It's worth having a go, since either you'll fix it, and save a few quid, or you won't, and whatever you do spend will seem like a bargain.

My own attempt was a failure, but after spending 3 hours trying and failing to get any purchase on that fking screw it made me feel actually pretty happy about spending £40 to have somebody else do it.

(I feel a bit daft now for not thinking of just leaving the new one lying around somewhere! Rage-induced tunnel vision I suppose. There's a fair bit of padding and insulation around the transmission tunnel, so there'd be room to secure it somewhere I'm sure, while still leaving some airflow for the heat sink.)

Edited by to3m on Tuesday 12th April 01:58

[Toltec]

I found it a bit awkward to do, however it is not particularly difficult if you prepare for it and take your time. In addition to the advice on the guide I used I found using a phone camera to take pictures helped visualise the position of the screws etc. as you cannot see them directly.

A magnetic bit holder helped to stop me from losing a screw on extraction and I used a small piece of electrical tape to hold the screws to the bitter when replacing.

I'd also recommend buying a good quality replacement, I found a German made Hella unit which was twice the price of the cheapest Chinese ones on eBay, but still much cheaper than a bmw one.

[stevesuk]

I'm a mechanical numpty, but I managed it. As others have said, it does involve contortion - but the sense of satisfaction when you reconnect everything and find it working is worth it. I also bought a Hella replacement, which was still working fine when I sold the car a year or more later. When looking for guides, make sure you find one for right hand drive...

Edited to add... I found this guide useful at the time http://www.gwynfryn.co.uk/pdfs/e46-hedgehog.pdf

Edited by stevesuk on Tuesday 12th April 08:46

[RanchoGrande]

Thanks for the feedback, I'm tempted to give it a bash, see how I get on.

In regards to just unplugging the old heatsink and leaving the new one hanging somewhere, is it that easy to just pull out the cable?

[RanchoGrande]

stevesuk said:

I'm a mechanical numpty, but I managed it. As others have said, it does involve contortion - but the sense of satisfaction when you reconnect everything and find it working is worth it. I also bought a Hella replacement, which was still working fine when I sold the car a year or more later. When looking for guides, make sure you find one for right hand drive...

Edited to add... I found this guide useful at the time http://www.gwynfryn.co.uk/pdfs/e46-hedgehog.pdf

Edited by stevesuk on Tuesday 12th April 08:46

This looks like a good guide, clearer than some others I've seen. Thanks!

[RanchoGrande]

would a torx allen key type tool be suitable to get the hidden torx screw out? Or would a torx screwdriver be better suited?

[stevesuk]

RanchoGrande said:

would a torx allen key type tool be suitable to get the hidden torx screw out? Or would a torx screwdriver be better suited?

There's one bolt at the back that I ended up getting at with a flexi-driver It's one of those jobs that afterwards, you understand where everything goes and it seems simple. Its feeling around in the dark that makes it hard.

[ftypical]

As previously mentioned, afterwards it can seem easy, but the trick is visualising where to insert the Torx tool while lying on your back in the front footwell.

I used a Halfords Torx key from a set of 8 for the hidden screw, plus a Torx bit in a screwdriver handle for the rest.

I went aftermarket for the new part, which may explain why the fan doesn't blow as hard as it used to.

HTH

[Huff]

It's just the same in an e39 - posturing upside down, on your back on the driver's seat, trying to reach for the clip that is at the limit of arm reach & dexterity& strength of fingers ( I say that as an upright-bass player!) None of it is actually difficult, just undignified and awkward - buggardly awkward.

Buy the Behr part, it's the updated OEM and probably best (much better / denser pins on heatsink design for one - since it is basically a power mosfet in series with the fan motor, told what to do output of the climate control module, it has to dump several tens of watts itself)

Word to the wise - don't leave it hanging /tucked-up as some suggest, the design obviously relies on the fan air path over it to cool it; without such it will fail again sooner rather than later. HTH.

Edited by Huff on Tuesday 12th April 21:55

[RanchoGrande]

I've gone for an aftermarket one from eBay, none of them were brands I recognised so I ended up picking the one with longest warranty and the most sales. We'll see how that goes.

I bought the one for my e36 from a random eBay seller and don't recall having any issues.

[Sardonicus]

Dont leave it dangling outside the airbox (like been suggested) its fitted where it is so it gets cooled by the rush of incoming air these things get bloody hot in use you have been warned, and yes on the E46 they can be troublesome be selective about fitting certain pattern one's too

[RanchoGrande]

Did this today...very very tricky.

I think the best advice I read online was to get a cushion and place it over the door sill! Ended up using a drapers precision driver as it was short enough to get to the hidden upper screw. I didn't replace the upper screw in case it breaks again and if it doesn't break again during my ownership it'll make life easier for the next owner.

Always feels good when you successfully complete a job like this!

[Spitfires]

Thread resurrection, but many thanks for this.

Successfully replaced my hedgehog at the weekend. Top tip is to use a captive washer on the upper torx to hold it in position during refitting; I made one out of plastic from a milk carton and it worked a treat.

Not an enjoyable job but would be much easier if I have to do it again (hopefully thanks to the advice above to buy the decent Behr part, I won't have to).