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M3AN

M3AN E36 M3 PLOG (Project Log)

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Today I replaced all of the belt tensioners and pulleys which was quite an easy job. I'm glad I did it because my old ones were knackered! They should all be replaced every Inspection II I would think. $190 + 1 hour.

Edit for elaboration:

Note how the belts are installed before you remove them (make a drawing or take clear pictures).

I already had new belts on (a few posts back in this thread). If you're reusing your belts mark either the direction of rotation (do you know that?) or the edge that's at the front of the car (pretty simple). You should (but not a disaster otherwise) keep the rotation direction the same.

I did this all from the top with the fan and cowl already removed, it's not necessary to access from the bottom unless you have a piston type tensioner on the air conditioning side (apparently!). I don't know what vehicles have the piston on the AC side but most of my searches came up with this arrangement (so it must be common). My car (09/96) has an eccentric wheel tensioner for the AC and a piston tensioner for the alternator side.

The AC side is pretty straight forward and obvious. When re-tensioning I had to torque the 10mm hex clockwise then do up the 13mm (or 11?) bolt whilst I held tension on the hex.

After you've taken the belt (8mm hex clockwise on the lower wheel will remove the tension) and both wheels off on the alternator side then the piston comes off with a frame assembly which is held in place by three 11mm bolts. Top one (long) is recessed and (normally) behind a circular plastic cover which easily pops off. The lower most bolt is on the bottom of the piston which is both easy to see and safe to remove (it's not load bearing). The final bolt is at about 11pm from the bottom (piston) bolt, impossible to see without a mirror of sorts but accessible nevertheless. The frame is a very cool assembly with heavy duty thrust bearings, re-grease the shaft before putting it back in.

Also replaced the passenger side radiator mount (rubber 'foot') which had mysteriously gone missing and left the radiator hanging off the clip at the top. All straight now. $5 + 10 mins.

I also replaced the valve cover gasket because I noticed a slight tear in my old one when the cover was last off. Didn't quite get that finished though and can't tackle again until Thursday.

I did the AC one as well, it's just not in this pic.

BeltsBits.jpg

Edited by M3AN
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Good work man! Great to see it all coming together and a real motivator to get on and do mine....

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^ Cheers, it's coming along. Unfortunately it seems that maintenance will never end...

I've added some information in my post above to elaborate on the procedure.

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Finally got the leather tears on the (old) driver's side seat patched from the inside and the bolsters repaired so it won't get worse, $50. Then gave that seat a 3 stage clean and care - LUX flakes, then Oakwood leather cleaner then Oakwood leather conditioner. It certainly cleaned up and is much better than before but reality doesn't change and the leather is past its use by date.

Interestingly I noticed that the leather on that seat has previously been painted or has some paint type treatment which is interesting because I've had the car since it was only 70,000k's old and it wasn't done under my care.

At least it looks much, much better from "my" side now!

RHSsm.jpg

Not so much from the other side but hey... shouldn't get much worse now.

LHSsm.jpg

Edited by M3AN
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And now for a confession because my experience needs to count for something!

Keen observers of this thread will have noticed that it took more than a few days to replace my valve cover gasket last week. Well that's because I have to admit I stripped two of the threads in the head for the valve cover bolts. Fab. <_<

I've had that cover on and off many times in the last year so I'm quite familiar with it and I always use a quality torque wrench and I always take extraordinary care (moreso after the trouble I had with the tensioner a year or so ago). Damn aluminium heads!

I would have had a minor stroke had it not been for the knowledge that a friend had a very similar experience some time ago and, also carefully using a torque wrench, stripped about 6 of theirs (gulp) but survived and recovered. So a quick phone call and a short trip and I had a 6x1mm Helicoil thread repair kit in my hands and a great sense of anxiety in my gut.

Whilst it's not a situation I'd wish on anyone it didn't end up being too much drama. Getting everything square when drilling the hole for the tap is the most daunting part because getting that bit wrong can be terminal. Since I did it by eye (no jig and lasers unfortunately) I'm 100% sure it's not all 100% straight (how could it be?) but I was still able to install and torque down the valve cover after fixing the two threads so it can't be far off.

If you do this go really slow, take your time, be careful of aluminium going everywhere, clean up well, take your time.

At least the Helicoils will be 30%+ stronger than the originals! Small mercies right?

My hypothesis of why this happens is:

The valve cover bolts have compressible rubber grommets installed from the factory. This rubber compresses with less than 8 Nm force which is the torque spec for those bolts. Therefore the BMW factory design implies that these grommets will compress a little when the bolt is tightened to 8 Nm. If this grommet can't compress all of that surplus torque will be applied to the threads. The bolts are steel, the head is aluminium.

 

My theory is that with age and heat these grommets fatigue to the point where they can't compress as readily. As a result 8 Nm is fully transferred to the threads and overwhelms them.

 

My guesses on how to avoid this:

1. Use new valve cover bolts every time you remove the valve cover ($$$)

2. Replace valve cover bolts every xxx km's so they always 'relatively' fresh ($)

3. Substitute 8 Nm spec with 7 Nm - this worked for me, see below.

 

When I did everything up after the Helicoils I didn't want to strip any more threads! So I tightened everything to 6 Nm and left it for an hour to compress/settle (gasket and grommets) then I went back and tightened everything to 7 Nm. I've left it all there and monitored for the last week and no drama. I also chased all of the bolts with a die to clean those threads and hand wound a tap into each of the "good" sockets in the head to make sure they were also clean (some were not).

Suffice to say I'm learning more about "fix-it engineering" than I ever wanted to know! :huh:

Ready to drill...

Helicoilsm.jpg

Edited by M3AN
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Very common. I had one thread on my old M3 cover that would probably need a helicoil next time the cover is off. It held this time but it was soft.

Well done on getting stuck in and fixing it yourself. Certainly drilling into that very expensive head must be daunting.

I heard of one guy on another forum that had to helicoil the whole lot after a shady mechanic over torqued the lot!

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Fitted my new UUC (3+ month delivery!) rear rotors today because they couldn't wait any longer. Mine were already below spec when I ordered the new ones in November so were pretty terrible (but still flat) when they came off today.

Simple job if you have the correct tools (which include a rather uncommon 7mm hex bit - find one of those in your typical set!), took about 90 mins all up.

Now I have near new rotors and pads on all 4 corners, braided lines are here and will go in soon alongside rebuilt OEM front calipers with brass sliders. Full flush with new fluid with the lines and I shouldn't have to think about brakes again for many moons.

Edit: reverting damn forum's auto-formatting f*#@.

Edited by M3AN
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I think it always pays to apply a grain of skepticism to factory torque specs. Sometimes chasing that magical number can be a little dangerous. Be it old or previously damaged bolts, or grommets as you suggest that alters the situation.

You tend to ignore the little sensations that let you know you're about to strip a thread when you have a torque spec to follow, and are waiting for the 'click'. I've damaged far more threads while tightening when using a torque wrench, than just playing it by ear with a ring and open end.

Sometimes I wonder if you're best just with a basic understanding of the materials you're dealing with and the forces that the fastener is going to have to resist, then just playing it by feel.

Anyway, good rescue! :D

Edited by duvey
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on alloy threads do it by feel ... you can feel when youve tighten it enough. Never had a problem with a bolt backing off using this method, even on an engine environment. Beats stripped threads.
Most factory torque settings are for brand new metal. Something to keep in mind.
Also especially on alloy, thread surface deformation is a real issue if your bolting and unbolting a lot.
If youre having issues getting a bolt to not seating itself you can always glue the bitch in with loc-tite. Its better than a busted thread. You can use the weak sauce loc-tite for this.

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I picked her up today from SJ (EUROHO / Apex Auto) having had the following completed:

- rebuilt, powder coated front callipers with brass slider bushings installed

- braided brake lines all round

- power flush with new Dot 4

I'll bring the rear callipers up to spec some time in the future, they're not a priority at the moment. I really want an alignment before I take her for a long drive to get a sense for any change in brake feel. Need an alignment because I also got:

- a quick ratio steering rack (purple label - 3 turns) from an E46 installed

- new power steering reservoir, hoses and clamps

- full flush with new ATF

Front end alignment tomorrow and I'm not going to drive it much or draw conclusions before then. Nevertheless initial impressions are interesting, it's certainly more direct and with limiters is about 2.75 turns lock to lock but it's also substantially heavier, more so than I expected, not at all uncomfortable but will take some getting used to.

Once it's aligned and all settled in I'll make my next assessment.

Photos, FWIW, soon.

SJ also called me to point out that my (new) valve cover gasket was leaking. Some will remember I didn't torque that down fully when I replaced it recently (for good reason) and I've now realised the consequences of that. Who knows if I can apply enough torque to stop the leak without stripping more threads? :unsure:

Finally, my coolant return line (hard line from radiator to overflow) produced a tiny split near the radiator when the car was started up. SJ and crew came up with a sweet fix but the line needs replacing - a portion was cut off and perished in my hands - could go at any time now - not sure how to check one without splitting it? I'll post some pics in this thread later.

Of course a big shout out to SJ and the team at Apex Autos, communication and resourcefulness was top notch, pleasure to deal with. :)

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I picked her up today from SJ (EUROHO / Apex Auto) having had the following completed:

- rebuilt, powder coated front callipers with brass slider bushings installed

- braided brake lines all round

- power flush with new Dot 4

I'll bring the rear callipers up to spec some time in the future, they're not a priority at the moment. I really want an alignment before I take her for a long drive to get a sense for any change in brake feel. Need an alignment because I also got:

- a quick ratio steering rack (purple label - 3 turns) from an E46 installed

- new power steering reservoir, hoses and clamps

- full flush with new ATF

Front end alignment tomorrow and I'm not going to drive it much or draw conclusions before then. Nevertheless initial impressions are interesting, it's certainly more direct and with limiters is about 2.75 turns lock to lock but it's also substantially heavier, more so than I expected, not at all uncomfortable but will take some getting used to.

Once it's aligned and all settled in I'll make my next assessment.

Photos, FWIW, soon.

SJ also called me to point out that my (new) valve cover gasket was leaking. Some will remember I didn't torque that down fully when I replaced it recently (for good reason) and I've now realised the consequences of that. Who knows if I can apply enough torque to stop the leak without stripping more threads? :unsure:

Finally, my coolant return line (hard line from radiator to overflow) produced a tiny split near the radiator when the car was started up. SJ and crew came up with a sweet fix but the line needs replacing - a portion was cut off and perished in my hands - could go at any time now - not sure how to check one without splitting it? I'll post some pics in this thread later.

Of course a big shout out to SJ and the team at Apex Autos, communication and resourcefulness was top notch, pleasure to deal with. :)

Surely the difference between 7 and 8nm can't be the only reason for a leaking valve cover. Maybe just some rtv?

Good to see you're staying on top of maintainence.

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Surely the difference between 7 and 8nm can't be the only reason for a leaking valve cover. Maybe just some rtv?

My concern too... and it's leaking in the same place the one I replaced was which makes me wary. But the surfaces were clean... I'll (add some oil) and wait to look at it over the weekend...

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Any damage to the sealing surfaces? Motor oil gets pretty creepy when its hot :) Related to a helicoil repair? Not ideal but i'm sure some tactially placed rtv would plug the gap.

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Any damage to the sealing surfaces? Motor oil gets pretty creepy when its hot :) Related to a helicoil repair? Not ideal but i'm sure some tactially placed rtv would plug the gap.

The surfaces were good I'm sure and it's not leaking near the repairs... but who knows. I'll consider all feedback objectively when I hunt the culprit down this weekend! ;)

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Steering Rack Update

Now that I've had the alignment done and taken the car for a couple of good drives across city, highway and back country I can confirm the E46 "sport" power steering rack (BMW part #7852974679) almost completely transforms how the front of the car feels.

- all of the dullness at the centre of steering is gone, the consequence is you can't be lazy with the wheel.

- related to above it doesn't require micro corrections but if you do give it input on centre it will respond.

- no problems with highway driving, no "twitchiness" as some report with some racks.

- around roundabouts, traffic pacifiers and through twisty roads it's substantially tighter and more direct than stock.

- it's much, much easier to rapidly change direction (and back and forth and back and forth and so on). That bit is quite fun - mint for AutoX.

- it requires much, much heavier input than stock and some people will not like this at all. I'd say try before you buy if you can.

I got a great deal on this low km rack and got it installed whilst other work was being done so looking back and splitting out costs the whole thing probably cost me $500 installed, add another $100 or so for hoses, clamps, fluid and perhaps a new reservoir and you're good to go.

At $500 or $600 I'd say 'recommended' if you track your car or generally enjoy driving it hard. If it cost much more or you don't drive hard all that often I'd probably say 'skip it' because I'm not convinced it would offer significant benefit.

I can't imagine why people would want the even tighter, more expensive and heavier Z3 rack unless it was for a track/race car, it would be a nightmare around town I reckon.

I'm very happy but am not going to rave on and say it's the be all and end all of M3 upgrades (get a braided clutch hose if you want the best upgrade ever lol!).

I'll sell drives to those that want to try it... ;)

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I have a 2.7 turn z3 rack in the e30 on 8 1/2 fronts .. works really well. oversteer has never been so easy.

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I have a 2.7 turn z3 rack in the e30 on 8 1/2 fronts .. works really well. oversteer has never been so easy.

Yes, you have the benefit of -100 kg at the front end!

Edit: diet

Edited by M3AN

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OEM brake porn - I have no real need for a BBK (after much deliberation) but these factory brakes are as good as I'll get them and they're now mounted on the front:


- powder coated calipers and mounts
- braided lines
- brass slider bushings and new pins
- new seals and boots
- new stainless fittings and cap

e36M3RebuiltCaliper01sm.jpg

Installed:

RebuiltBrakesOn01.jpg

Edited by M3AN
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And I wanted to add a bit of info about an alarming coolant leak that developed - my hard 'return' line from the radiator to the overflow tank split and has started to perish! ? If that fails it will compromise the entire cooling system.

A small split turned into pieces that simply cracked off! See:

ReturnLineSm.jpg

Don't be too aggressive when you check yours! And be aware that there are multiple parts/years so check for your specific model. Mine (~1.3m) was only $30 to replace from the dealer.

Edited by M3AN

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Steering Rack Update

I have a very interesting finding that there's not a lot of discussion about despite the number of times this 'mod' has been used and discussed on the 'net (ad nauseum if you don't know). Ash (Heisenberg) recently completed a similar swap on his E30 and noticed that the boot venting mechanism for the E30/6 racks was different to that of the E46.

After a direct swap of an E46 rack into an E30/6, retaining the original E30/6 tie rods, the rack boots will both balloon and "suck in" (vacuum compress) horribly as the steering swings from lock to lock. It's immediately obvious when you take a look and it's quite dramatic, it's sure to ruin the boots or boot seals over time.

The E30/6 rack uses a separate vacuum hose to vent between boots whereas the E46 inner tie rods are internally vented and it seems that if they are a direct swap then that's the obvious solution. There's conflicting information out there in the "swapability" so I'm in the process of investigating that.

There's no authoritative information out there (that I can find) on a fix. It seems most people aren't even aware of the issue.

In the meantime I've drilled a 4mm hole into each boot which is less than ideal but better than what I was witnessing beforehand! If the E46 inner rods (and therefore boots) work then those holes will be discarded to the rubbish.

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Hey mate, are you home? Keen to take a look at the rack. I Have purchased one but unsure if I'm going to put it in....

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beersies @ Daves' hahahahaha

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