E91 Straight Six Bearding
Discussion
Crank pully looks a bit buggered, I suspect that'll need replacing.
Front of the engine looks absolutely filthy. I've tried to clean it up a bit with GUNK degreaser. As Helix says, probably a contributing factor.
New Tensioner and pully on (not torqued up yet).
Very stupid question for those in the know...according to this video:
Tensioner is 25Nm + 90 degrees.
So to clarify, once torqued to 25Nm, get the click...then literally cont another 90 degrees (with the torque wrench at the same setting)?
g3org3y said:
Crank pully looks a bit buggered, I suspect that'll need replacing.
Front of the engine looks absolutely filthy. I've tried to clean it up a bit with GUNK degreaser. As Helix says, probably a contributing factor.
New Tensioner and pully on (not torqued up yet).
Very stupid question for those in the know...according to this video:
Tensioner is 25Nm + 90 degrees.
So to clarify, once torqued to 25Nm, get the click...then literally cont another 90 degrees (with the torque wrench at the same setting)?
And yes to the torque question IIRC
Good going. As others have mentioned. Oil filter housing leaks can get on the belt and ruin it.
When you torque the bolt, use the torque wrench for the 25nm, but not for the degrees. You’ll be over straining it and could take it out of calibration. A normal bar will do it, you don’t need to be degree perfect. I usually do two 45° turns.
When you torque the bolt, use the torque wrench for the 25nm, but not for the degrees. You’ll be over straining it and could take it out of calibration. A normal bar will do it, you don’t need to be degree perfect. I usually do two 45° turns.
JakeT said:
Good going. As others have mentioned. Oil filter housing leaks can get on the belt and ruin it.
When you torque the bolt, use the torque wrench for the 25nm, but not for the degrees. You’ll be over straining it and could take it out of calibration. A normal bar will do it, you don’t need to be degree perfect. I usually do two 45° turns.
^^^When you torque the bolt, use the torque wrench for the 25nm, but not for the degrees. You’ll be over straining it and could take it out of calibration. A normal bar will do it, you don’t need to be degree perfect. I usually do two 45° turns.
That's the one; forgot to say that using a breaker bar is better
My pals got one of them small degree gauges that he uses for stuff where it needs to be more accurate rather than by 'eye' etc
VS02 said:
How comes the E90 M3 had the headlights of the E92? I always thought it would have looked better with the typical E90 headlights. Such a great looking car.
I thought that too, shame they used the E92 lights on the E90 M3 as it would otherwise have been a very handsome car with the E90 lights. They've done something similar with the latest M3 Touring, I thought it would look spectacular but they've ruined the look of it by fitting the hideous pig snout grille from the 4-series 
Looks like you had a very close call with the belt. There are countless tales of woe online where pieces of the belt get sucked into the engine via the front main seal, as the gap between the pulley and block is so small. Sorting that requires removal of the sump pan to pick out all the bits before they block the oil pickup, which is no small job.
Ageing of the belt (hastened by oil contamination) is one cause, but the tensioner can also develop some play which allows the belt to walk off. It's well worth replacing the belt and tensioners on any N52/53/54 engine if it hasn't been done recently. The N54 also has an additional concern whereby due to play in the engine mounts allows the power steering pulley to contact the subframe and shatter, tearing the belt to shreds in the process. This doesn't affect the non-turbo engines as the power steering pulley is mounted higher up.
Ageing of the belt (hastened by oil contamination) is one cause, but the tensioner can also develop some play which allows the belt to walk off. It's well worth replacing the belt and tensioners on any N52/53/54 engine if it hasn't been done recently. The N54 also has an additional concern whereby due to play in the engine mounts allows the power steering pulley to contact the subframe and shatter, tearing the belt to shreds in the process. This doesn't affect the non-turbo engines as the power steering pulley is mounted higher up.
g3org3y said:
Crank pully looks a bit buggered, I suspect that'll need replacing.
Front of the engine looks absolutely filthy. I've tried to clean it up a bit with GUNK degreaser. As Helix says, probably a contributing factor.
New Tensioner and pully on (not torqued up yet).
Very stupid question for those in the know...according to this video:
Tensioner is 25Nm + 90 degrees.
So to clarify, once torqued to 25Nm, get the click...then literally cont another 90 degrees (with the torque wrench at the same setting)?
Thanks all. 
Done (pin still in situ)
Checked and rechecked the correct belt 'path' before removing the pin. Even double checked in my Haynes manual.
Pin removed and it's all good.
Started up fine and drives well. Crankshaft pully doesn't look at smooth as I'd like so will have a chat with the mechanic about getting that replaced. Looks a bit of a faff in terms of access.
Lucky escape methinks! Could have been A LOT worse.
Done (pin still in situ)
Checked and rechecked the correct belt 'path' before removing the pin. Even double checked in my Haynes manual.
Pin removed and it's all good.
Started up fine and drives well. Crankshaft pully doesn't look at smooth as I'd like so will have a chat with the mechanic about getting that replaced. Looks a bit of a faff in terms of access.
Lucky escape methinks! Could have been A LOT worse.
Edited by g3org3y on Wednesday 22 June 11:02
More problems...
Yesterday after sorting the belt etc took the car for a 20 min test drive, no problems.
My wife took it out after and drove it for >1hr, again no problems.
Today she drove it into town (maybe 20 min drive) and had a yellow temp warning light and as she pulled up and stopped the car, went red. No reported limp mode or loss of power. No water leaking.
She called me and I advised for her to run her errands (30 mins) and call me back when she's done. I was reluctant for her to check the coolant as I'd likely still be v hot. I advised her to stick the temp on max, fan on max and nurse the car home. Apparently she's driven home, no warning lights and car runs ok.
Differentials:
- Waterpump/thermostat failure? Was changed probably only 30k miles ago. Waterpump is not one of the components of the serpentine belt arrangement.
- Fan (or other component/sensor) damaged by the flailing/broken belt. Should this spin freely by hand when the engine is off? Are these electric?
Any other ideas? TIA.
Yesterday after sorting the belt etc took the car for a 20 min test drive, no problems.
My wife took it out after and drove it for >1hr, again no problems.
Today she drove it into town (maybe 20 min drive) and had a yellow temp warning light and as she pulled up and stopped the car, went red. No reported limp mode or loss of power. No water leaking.
She called me and I advised for her to run her errands (30 mins) and call me back when she's done. I was reluctant for her to check the coolant as I'd likely still be v hot. I advised her to stick the temp on max, fan on max and nurse the car home. Apparently she's driven home, no warning lights and car runs ok.
Differentials:
- Waterpump/thermostat failure? Was changed probably only 30k miles ago. Waterpump is not one of the components of the serpentine belt arrangement.
- Fan (or other component/sensor) damaged by the flailing/broken belt. Should this spin freely by hand when the engine is off? Are these electric?
Any other ideas? TIA.
helix402 said:
Fans are electric and PWM driven by the engine ecu. They do fail.
And just checked on ECP - they are not cheap! >£300bodhi said:
Could the flailing belt have damaged one of the coolant pipes?
Possible. I will have to check it all over this evening after work.Or damage to one of the sensors or connectors that activate the rad (or damage to the rad itself).
I've just checked on my 630i and the fan is free to spin by hand when the car is off (wasn't sure on these electric fans).
What a faff.
bmwmike said:
The DME tests the fan by spinning it up and then testing the electricity it generates. If it is too tight or not working it should flag a code. Any codes?
The space for the front end drive belt is tight, you might have just knocked a connector loose?
Will have to check when I get home re codes.The space for the front end drive belt is tight, you might have just knocked a connector loose?
As mentioned, the car was driven for 20mins + 1hr yesterday with no issues or warnings. Also according to wife, car didn't go into any limp mode today.
I'm sure that belt could have caused all manner of damage while flailing about there!
EDIT to add: when I was changing the belt, I did try to spin the fan (by hand while the engine was off obvs) and it didn't move. Hence my question as to whether this was normal or abnormal with these electric fans.
Edited by g3org3y on Thursday 23 June 14:47
If I were a betting man I’d also say fan from what you’ve written.
If she was in town it’s more low speed work, and the car will rely on the fan for cooling. But if she’s been moving coming home and done the low speed work first there’s going to be enough airflow over the rad.
Easiest test Is to put the air conditioning on and see if the fan runs.
If she was in town it’s more low speed work, and the car will rely on the fan for cooling. But if she’s been moving coming home and done the low speed work first there’s going to be enough airflow over the rad.
Easiest test Is to put the air conditioning on and see if the fan runs.
pmorg4 said:
VS02 said:
How comes the E90 M3 had the headlights of the E92? I always thought it would have looked better with the typical E90 headlights. Such a great looking car.
I thought that too, shame they used the E92 lights on the E90 M3 as it would otherwise have been a very handsome car with the E90 lights. They've done something similar with the latest M3 Touring, I thought it would look spectacular but they've ruined the look of it by fitting the hideous pig snout grille from the 4-series Never minded it on the E9x or F8x cars to be honest, although it does make me sad to imagine how good a G80 M3 with the G20 3 Series grille and headlights could look.
Apologies for the de-railing, back to discussion of N52s and N53s...
When the water pump died on my 325i I got an amber temperature light followed by red in less than a mile but I was able to stop. When my Z4 one died I drove 5 or 6 miles further to get off an unlit dual carriageway in December and it went into limp mode!
But if your car had a new one 30K miles ago it shouldn't be that, unless the pump fitted was a knock-off part OE pumps were Pierburg - just don't buy from BMW as they charge over £500 for them.
You probably need to start with reading fault codes!
Good luck finding the problem and getting it fixed.
But if your car had a new one 30K miles ago it shouldn't be that, unless the pump fitted was a knock-off part OE pumps were Pierburg - just don't buy from BMW as they charge over £500 for them.
You probably need to start with reading fault codes!
Good luck finding the problem and getting it fixed.
bmwmike said:
Fan should easily spin. Check there is no belt jamming it up?
Fan did not spin easily.
Hooked the edge and pulled.
Got out all the bit wrapped round but it's lodged/stuck in the mechanism of the fan itself. No pulling will get it out, tried loads of silicon spray to lube it up.
Will remove the fan over the w/e and see if can dismantle...otherwise it's new fan time.
Damn, thought we'd got away with this...
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