Help! E91 N43B20A timing chain problems?
Discussion
Hi,
I got a 2010 320i with 120k on the clock a few months ago, and while it's been fine I've noticed a few worrying things:
A thread somewhere suggested looking down the oil filler cap at the chain. I did this today, and it's like this:
https://www.youtube.com/watch?v=JFq8dDW4RSw
So a really scary amount of slack - almost enough that it could jump a tooth. Right after running the car there's a lot less, but there it feels like it's too much.
There doesn't really seem to be wear on the top plastic guide though - it's indented, but it looks like it's supposed to be like that.
Does anyone know about these engines? Is this a sign of trouble, or are they usually that slack?
(And no, I didn't buy from a dealer
)
How painful is it to replace the chain? There seems to be workshop guide here:
workshop-manuals.com/bmw
But is there a good forum guide somewhere (or a downloadable manual) that mentions exactly which bits I need to buy?
I'm relatively clued/tooled up (I've replaced pistons/valves on non-BMW engines and done an engine swap before) but is there any kind of 'special tool' that I *really* need for this?
Thanks!
I got a 2010 320i with 120k on the clock a few months ago, and while it's been fine I've noticed a few worrying things:
- Got low oil pressure light once - stopped immediately, restarted and it went away (I changed oil right after this)
- Slight clatter occasionally at low revs
- Sometimes it's a little jerky pulling away
- When it's been ~4 hours since last driven, takes a few seconds of turning over before it starts.
- Got Engine Warning light twice. First time it was NOx sensor, second time it disappeared before I could find out what it was.
A thread somewhere suggested looking down the oil filler cap at the chain. I did this today, and it's like this:
https://www.youtube.com/watch?v=JFq8dDW4RSw
So a really scary amount of slack - almost enough that it could jump a tooth. Right after running the car there's a lot less, but there it feels like it's too much.
There doesn't really seem to be wear on the top plastic guide though - it's indented, but it looks like it's supposed to be like that.
Does anyone know about these engines? Is this a sign of trouble, or are they usually that slack?
(And no, I didn't buy from a dealer
)How painful is it to replace the chain? There seems to be workshop guide here:
workshop-manuals.com/bmw
But is there a good forum guide somewhere (or a downloadable manual) that mentions exactly which bits I need to buy?
I'm relatively clued/tooled up (I've replaced pistons/valves on non-BMW engines and done an engine swap before) but is there any kind of 'special tool' that I *really* need for this?
Thanks!
Edited by rabidh on Sunday 14th August 12:58
Great, thanks! I guess if there's no EML then it's less likely the chain has slipped?
Is there any way to check easily? I guess I could disconnect the Vanos valves and then check what the cam timings are at their base values via OBD2? I have no idea what the correct numbers are though
So if I replace the tensioner and the chain is no longer slack, it's job done?
Also, I found a video of someone doing the change on an N42 - seems similar: https://www.youtube.com/watch?v=bzZsaMG5a-s
(Although more painful on N43 because of the direct injection)
And yeah, those brackets to hold the cams in place seem vital - if only for the Vanos timing wheels.
Is there any way to check easily? I guess I could disconnect the Vanos valves and then check what the cam timings are at their base values via OBD2? I have no idea what the correct numbers are though
So if I replace the tensioner and the chain is no longer slack, it's job done?
Also, I found a video of someone doing the change on an N42 - seems similar: https://www.youtube.com/watch?v=bzZsaMG5a-s
(Although more painful on N43 because of the direct injection)
And yeah, those brackets to hold the cams in place seem vital - if only for the Vanos timing wheels.
Edited by rabidh on Sunday 14th August 14:06
I just looked at the tensioner, and it has the thin end on it rather than the older 'thick' one like this - so I think that means it's already been replaced?
I guess it might be worth doing again just in case?
One of the places I looked, someone mentioned that the oil pressure warning could have been caused by a broken chain guide blocking the oil pickup. I don't know if that's realistic or if I'm just imagining the worst?
The other thing I'd forgotten to mention is the engine doesn't really have the power I'd expected. Around 1000-2500 rpm it's really torquey, but it runs out of steam pretty soon after that. From what I can tell torque should peak at 4250 rpm and it really doesn't feel like that at all. I guess potentially another sign the timing is off.
I guess it might be worth doing again just in case?
One of the places I looked, someone mentioned that the oil pressure warning could have been caused by a broken chain guide blocking the oil pickup. I don't know if that's realistic or if I'm just imagining the worst?
The other thing I'd forgotten to mention is the engine doesn't really have the power I'd expected. Around 1000-2500 rpm it's really torquey, but it runs out of steam pretty soon after that. From what I can tell torque should peak at 4250 rpm and it really doesn't feel like that at all. I guess potentially another sign the timing is off.
Quick update - the tensioner on the car was an OEM BMW one, of the new design. Although when I went to undo it I found it was so loose it could be unscrewed by hand(!) - so I assume it has been replaced at some point.
I had a quick fiddle with it, and it appears to have worn a groove into itself such that it 'catches' halfway when the internal spring pushes the plunger out. This might have been what was happening when it was pressing on the chain guide - it can't have helped anyway.
As suggested, I've replaced it with a Febi one, and it does appear to have tightened up the chain. I saw somewhere that you could lift the oil filler while the car was running and see if the chain was wobbling, and it seemed to be dead straight - although it was hard to see properly through the fountain of oil spurting into my face.
It's still a little slack after the engine has stopped, but not too bad. I may still replace the chain in the future just to be sure, but I'll see how it runs for now.
Thanks for the help!
I had a quick fiddle with it, and it appears to have worn a groove into itself such that it 'catches' halfway when the internal spring pushes the plunger out. This might have been what was happening when it was pressing on the chain guide - it can't have helped anyway.
As suggested, I've replaced it with a Febi one, and it does appear to have tightened up the chain. I saw somewhere that you could lift the oil filler while the car was running and see if the chain was wobbling, and it seemed to be dead straight - although it was hard to see properly through the fountain of oil spurting into my face.
It's still a little slack after the engine has stopped, but not too bad. I may still replace the chain in the future just to be sure, but I'll see how it runs for now.
Thanks for the help!
Thanks for all the help! Sorry for the lack of replies but for whatever reason I stopped getting notifications
The engine feels better now, but it still has some chugging at lower revs which could be coil packs.
Good point about 'borrowed time' though - especially if the slackness is due to the chain having stretched that much. I did get a Febi chain kit and the cam locking kit, so I'll probably give the chain replacement a go next week.
The engine feels better now, but it still has some chugging at lower revs which could be coil packs.
Good point about 'borrowed time' though - especially if the slackness is due to the chain having stretched that much. I did get a Febi chain kit and the cam locking kit, so I'll probably give the chain replacement a go next week.
Well, I had a stab at it today, and it's looking promising. I got everything locked off, stripped down, and replaced the chain. The old guide and chain actually look pretty good - nothing seems broken and I can't make out any wear at all, so I'm starting to wonder if the chain had been replaced previously.
Worst job was getting the peg into the flywheel. Must have taken an hour or so, even after I chamfered the end of the pin a little to give me a fighting chance...
Turns out my kit doesn't have the replacement cam and crank bolts in, and I didn't want to chance it so I'll wait until I can get new ones before I reassemble everything.
I do have some questions now though, if anyone can help out:
Is there any kind of 'key' for the timing? On other cars I've had the timing chain has had a key to stop movement, but I don't see anything like that here... Is it just the pressure of the bolts that holds everything in place tight enough that it doesn't slip?
Kind of related - do the Vanos pulleys need to be aligned somehow, or is it literally just the positioning of the trigger wheel on each one that matters?
Also, my 'timing tool' doesn't fit very snugly in the timing wheel, so there's almost a degree of slop - is that ok, or should I attempt to pack it to reduce the wobble? I'm a bit paranoid about any packing I put in falling into the sump
The timing kit also has 3 extra items in it that I'm not using (http://www.ebay.co.uk/itm/271639646197 - the 2 silver pins, and the tuning-forky thing). Are they needed, or are they for the balance shafts?
Is there a downloadable workshop manual? I've been using workshop-manuals.com, but it's a complete pain when flicking through the pages, and even after donating, it's not substantially better.
thanks!
Worst job was getting the peg into the flywheel. Must have taken an hour or so, even after I chamfered the end of the pin a little to give me a fighting chance...
Turns out my kit doesn't have the replacement cam and crank bolts in, and I didn't want to chance it so I'll wait until I can get new ones before I reassemble everything.
I do have some questions now though, if anyone can help out:
Is there any kind of 'key' for the timing? On other cars I've had the timing chain has had a key to stop movement, but I don't see anything like that here... Is it just the pressure of the bolts that holds everything in place tight enough that it doesn't slip?
Kind of related - do the Vanos pulleys need to be aligned somehow, or is it literally just the positioning of the trigger wheel on each one that matters?
Also, my 'timing tool' doesn't fit very snugly in the timing wheel, so there's almost a degree of slop - is that ok, or should I attempt to pack it to reduce the wobble? I'm a bit paranoid about any packing I put in falling into the sump
The timing kit also has 3 extra items in it that I'm not using (http://www.ebay.co.uk/itm/271639646197 - the 2 silver pins, and the tuning-forky thing). Are they needed, or are they for the balance shafts?
Is there a downloadable workshop manual? I've been using workshop-manuals.com, but it's a complete pain when flicking through the pages, and even after donating, it's not substantially better.
thanks!
> The timing pin should fit tightly in the flywheel. Is this the 'timing wheel' do you mean?
The pin fits tight in the flywheel - I meant the widgets right on the end of the camshaft sprockets that tell the ECU where the cams are. When I fit the timing tool onto the car, they can still move around by maybe a degree.
There are still 2 silver 'pins' in the set (top right of the box on http://www.ebay.co.uk/itm/271639646197) - I'm not sure what they're for?
Thanks for the advice on the fitting - so you'd advise against doing the 300Nm torque-up using the crank pin to stop the crank turning? It looked quite meaty but I guess it'd be a disaster if the pin couldn't be removed.
The pin fits tight in the flywheel - I meant the widgets right on the end of the camshaft sprockets that tell the ECU where the cams are. When I fit the timing tool onto the car, they can still move around by maybe a degree.
There are still 2 silver 'pins' in the set (top right of the box on http://www.ebay.co.uk/itm/271639646197) - I'm not sure what they're for?
Thanks for the advice on the fitting - so you'd advise against doing the 300Nm torque-up using the crank pin to stop the crank turning? It looked quite meaty but I guess it'd be a disaster if the pin couldn't be removed.
Thanks for the help everyone - it's done now.
I had to torque up the crank bolt by feel because my wrench only goes up to 200 so I may have over-done it a little - I can see what everyone means though, it feels like a scary amount! I got my wife under the car with a big screwdriver in the end rather than chancing that pin
I replaced the coil packs at the same time, so I'm not sure if it's that or the ECU still learning after I disconnected the battery (turns out this is a good idea or it'll spray petrol at you every 10 minutes), but the car does seem to have more power at the top end now (it tailed off before).
There's a slightly disconcerting chain-like whine in the background now, but I assume that might get quieter when the chain beds in...
I had to torque up the crank bolt by feel because my wrench only goes up to 200 so I may have over-done it a little - I can see what everyone means though, it feels like a scary amount! I got my wife under the car with a big screwdriver in the end rather than chancing that pin
I replaced the coil packs at the same time, so I'm not sure if it's that or the ECU still learning after I disconnected the battery (turns out this is a good idea or it'll spray petrol at you every 10 minutes), but the car does seem to have more power at the top end now (it tailed off before).
There's a slightly disconcerting chain-like whine in the background now, but I assume that might get quieter when the chain beds in...
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