I was setting off towards home from Birmingham last weekend, a journey of about 90 miles, and when I started my car I heard an almighty screech which lasted a couple of seconds then stopped.
I made a mental note to check the serpentine belt when I got home as I was sure this would be where the noise was emanating from. When I exited the M40 at Princes Risborough I once again heard another almighty screech which last a few seconds. All the pressures and temps seemed normal so I carried on and parked up when I got home.
I looked in the engine compartment yesterday to see if the serpentine belt looked like it needed replacing and was greeted with two of the belts ribbed sections completely gone, bits of belt all over the engine compartment and the tension pulley had exploded, the plastic runner had gone, there was just the bearing left. One of the idler pulleys had chunks out of it too.
I rang Porsche Reading and ordered a new set of pulleys, the tension pulley securing bolt and a new belt. I then set about stripping off the old pulleys.
Everything was going swimmingly until I tried removing the tension pulley from its arm. The 24mm bolt was so tight it took my longest breaker bar to get it to move, then I managed to undo it about 3/4 of a turn before it bound up and locked solid. This left me with a tension bearing loose in the tension arm which made applying any force very tricky, in the end the 15mm bolt rounded off as the only way to grip it is with an open ended spanner as there's not enough room to get a ring spanner between the bolt head and the engine casing.
I looked online to see if there was another way to tackle this and it seems the accepted wisdom is to remove the steering pump/aircon pump bracket which the tension arms spring housing is bolted to. This will give enough room to get a ring spanner on the 15mm bolt. Of course this means removing the steering pump and the aircon pump, not a job I fancied!
Looking at the exploded diagrams it appeared that the tension arm is held in place onto the tensioner by an allen screw that's screwed in from the back.
After taking an iPhone photo I could see the mounting bracket and the proximity of the oil filler tube.
Another photo confirmed the allen screw is there and would be accessible with the oil tube out of the way.
I figured if I could undo the screw the tension arm should pull through and I'll be able to take it out.
Of course to achieve this the oil filler tube needs to be removed and to achieve this the alternator has to be removed. Again I read horror stories about how difficult it is to remove the alternator in situ so I wasn't looking forward to the job.
My conclusion was the alternator is actually quite simple to remove, just disconnect the battery then it's just two bolts holding it in place, one of which was removed anyway as it carries one of the pulleys I'm replacing. Remove the other bolt, wiggle the alternator free so I could access the back, unclip the cable and unbolt the starter cable and out it came. The oil tube needs just two bolts undoing to remove making sure to plug the crankcase hole with a rag.
With these components out of the way it just needed a 5mm allen key to undo the tension lever securing screw and the tension lever pulls out from the rear of the car. Once out it was a simple job to get a ring spanner on the 15mm bolt and undo the 24mm one.
This is the engine bay with the lever removed, I'm just waiting for the parts to arrive so I can get on with the rebuild.
This is the remnants of the belt and the exploded tension pulley.
Even one of the idler pulleys had taken damage, probably where a chuck of tension pulley had been carried through.
The tension arm looks like this with it's securing bolt screwed in the end.
This only took a couple of hours to do and a lot of that was due to seized bolts needing coaxing out.
However when I tidied everything away I shut the engine compartment then the frunk and immediately thought *****, the battery's disconnected! This meant I had no way of locking the doors or opening the frunk!
I had a 12v battery on my BMW motorbike so I brought that alongside and jumped the power to the emergency bonnet "fuse" and the door striker plate but nothing happened. I left it a while and still nothing either by the switch or the remote. I'm not sure if the fact the battery was disconnected had anything to do with it or not but that method certainly wasn't working.
The other method I'd read about that isn't documented in the owners manual is the emergency release cable in the nearside wheel arch. Just remove the wheel and wheel arch liner, pull the cable and you're in. Guess where my locking wheel key was? Yep, where it's meant to be in the frunks toolkit!
I jacked up the car and discovered it is possible to remove the lower wheel arch liner with the wheel still fitted, even though I couldn't turn the steering wheel due to the lack of power (the steering lock stays engaged). I found the cable, gave it a pull with a pair of pliers and eventually I was in, you can see the cable poking out underneath the wiring harness in this photo.
This momentary lapse of concentration took me longer to sort out than actually removing all the damaged pulleys, alternator, oil filler and tension arm. I won't make that mistake again!
I made a mental note to check the serpentine belt when I got home as I was sure this would be where the noise was emanating from. When I exited the M40 at Princes Risborough I once again heard another almighty screech which last a few seconds. All the pressures and temps seemed normal so I carried on and parked up when I got home.
I looked in the engine compartment yesterday to see if the serpentine belt looked like it needed replacing and was greeted with two of the belts ribbed sections completely gone, bits of belt all over the engine compartment and the tension pulley had exploded, the plastic runner had gone, there was just the bearing left. One of the idler pulleys had chunks out of it too.
I rang Porsche Reading and ordered a new set of pulleys, the tension pulley securing bolt and a new belt. I then set about stripping off the old pulleys.
Everything was going swimmingly until I tried removing the tension pulley from its arm. The 24mm bolt was so tight it took my longest breaker bar to get it to move, then I managed to undo it about 3/4 of a turn before it bound up and locked solid. This left me with a tension bearing loose in the tension arm which made applying any force very tricky, in the end the 15mm bolt rounded off as the only way to grip it is with an open ended spanner as there's not enough room to get a ring spanner between the bolt head and the engine casing.
I looked online to see if there was another way to tackle this and it seems the accepted wisdom is to remove the steering pump/aircon pump bracket which the tension arms spring housing is bolted to. This will give enough room to get a ring spanner on the 15mm bolt. Of course this means removing the steering pump and the aircon pump, not a job I fancied!
Looking at the exploded diagrams it appeared that the tension arm is held in place onto the tensioner by an allen screw that's screwed in from the back.
After taking an iPhone photo I could see the mounting bracket and the proximity of the oil filler tube.
Another photo confirmed the allen screw is there and would be accessible with the oil tube out of the way.
I figured if I could undo the screw the tension arm should pull through and I'll be able to take it out.
Of course to achieve this the oil filler tube needs to be removed and to achieve this the alternator has to be removed. Again I read horror stories about how difficult it is to remove the alternator in situ so I wasn't looking forward to the job.
My conclusion was the alternator is actually quite simple to remove, just disconnect the battery then it's just two bolts holding it in place, one of which was removed anyway as it carries one of the pulleys I'm replacing. Remove the other bolt, wiggle the alternator free so I could access the back, unclip the cable and unbolt the starter cable and out it came. The oil tube needs just two bolts undoing to remove making sure to plug the crankcase hole with a rag.
With these components out of the way it just needed a 5mm allen key to undo the tension lever securing screw and the tension lever pulls out from the rear of the car. Once out it was a simple job to get a ring spanner on the 15mm bolt and undo the 24mm one.
This is the engine bay with the lever removed, I'm just waiting for the parts to arrive so I can get on with the rebuild.
This is the remnants of the belt and the exploded tension pulley.
Even one of the idler pulleys had taken damage, probably where a chuck of tension pulley had been carried through.
The tension arm looks like this with it's securing bolt screwed in the end.
This only took a couple of hours to do and a lot of that was due to seized bolts needing coaxing out.
However when I tidied everything away I shut the engine compartment then the frunk and immediately thought *****, the battery's disconnected! This meant I had no way of locking the doors or opening the frunk!
I had a 12v battery on my BMW motorbike so I brought that alongside and jumped the power to the emergency bonnet "fuse" and the door striker plate but nothing happened. I left it a while and still nothing either by the switch or the remote. I'm not sure if the fact the battery was disconnected had anything to do with it or not but that method certainly wasn't working.
The other method I'd read about that isn't documented in the owners manual is the emergency release cable in the nearside wheel arch. Just remove the wheel and wheel arch liner, pull the cable and you're in. Guess where my locking wheel key was? Yep, where it's meant to be in the frunks toolkit!
I jacked up the car and discovered it is possible to remove the lower wheel arch liner with the wheel still fitted, even though I couldn't turn the steering wheel due to the lack of power (the steering lock stays engaged). I found the cable, gave it a pull with a pair of pliers and eventually I was in, you can see the cable poking out underneath the wiring harness in this photo.
This momentary lapse of concentration took me longer to sort out than actually removing all the damaged pulleys, alternator, oil filler and tension arm. I won't make that mistake again!
