Chain or Pulley....

H

houseofscouse

Member
Morning all!

04 plate m54 on 99k has developed a not so good noise coming from the engine bay. Definitely sounds like it's from the front of the block. Trying to work out if it's pulley related or chain. Am a bit worried as it does sound "internal" to me.

Am intending on taking the fan out today and take a closer look. Any practical tips I can take to try to eliminate/Narrow down what it might be?

The noise isn't just on idle and does speed up a bit under revs.

I had chain rattle on the notorious N47 engine in an on e90 and that sounded like a tractor. This noise isn't the same.
 
Depends on the kind of noise I guess. Rattle, squeak or squeal?
Try running the engine and directing a squirt of WD40 at each pulley in turn. If it stops that's your problem.
Check condition of the belts.
Obviously make sure there's no loose attachment bolts on pulleys, water pump etc.

Can also try running without the belts on to see if the noise goes.
Not for long though as obviously the alternator won't be running.
 
Okay...just checked the oil level as a simple starter for ten. Cappuccino. Coolant smells ever so slightly exhausty. Head gasket I'm guessing. I'm not suspecting the "internal" noise is going to be an inadequately lubricated chain.

Any ideas what I could be looking at to get the HG done?
 
houseofscouse said:
Okay...just checked the oil level as a simple starter for ten. Cappuccino. Coolant smells ever so slightly exhausty. Head gasket I'm guessing. I'm not suspecting the "internal" noise is going to be an inadequately lubricated chain.

Any ideas what I could be looking at to get the HG done?
Click to expand...
That's a rare fail on the M54.
Never done one so can't really help I'm afraid.
 
I think you need to dig a little deeper if possible as there could be other issues. As you say, head gasket, chain, possible wear debris in the oil system. While it's apart you'd be looking at probably replacing the water pump, thermostat, vanos if not already done.
Price it all up then think on whether an engine swap would be more economical. Given the (usually) reliable nature of these engines there are now a lot of cars being broken for bodywork issues that still have a good motor.
Not sure of your abilities or facilities, but one option may be to get a breaker, swap the engine and sell other parts to recoup some of your outlay.

But do make sure of your diagnosis first.
 
The other day my engine was making a terrible noise. Eventually found it was the electronics of the Disa valve making a racket. Perhaps you can post a video with the noise.
 
Okay...logic has kicked in over emotion now.

3 theories:

1 - car does about 6-7 miles daily so the bit of gunk could be condensation. But that wouldn't explain the scrapey/rattly noise. So I think this is clutching at straws. I could take it on a longer run to see if this clears the gunk/condensation, but given the alternative scenarios I would think this is not wise at all.

2 - If I accept that it's likely oil and water mixed, it could be that when I changed the oil filter housing gasket in June, it didn't seat properly and water has found its way into the oil. This would lead to inadequate lubrication and the chain isn't happy because of it.

3 - head gasket failure has led to water getting into the oil. If I do a compression test I can ascertain if the Zed is down on compression and thus likely culprit is HG.

Based on the above, I figure borrow my mates compression testing kit first and see how I get on. Thoughts?
 
houseofscouse said:
Okay...logic has kicked in over emotion now.

3 theories:

1 - car does about 6-7 miles daily so the bit of gunk could be condensation. But that wouldn't explain the scrapey/rattly noise. So I think this is clutching at straws. I could take it on a longer run to see if this clears the gunk/condensation, but given the alternative scenarios I would think this is not wise at all.

2 - If I accept that it's likely oil and water mixed, it could be that when I changed the oil filter housing gasket in June, it didn't seat properly and water has found its way into the oil. This would lead to inadequate lubrication and the chain isn't happy because of it.

3 - head gasket failure has led to water getting into the oil. If I do a compression test I can ascertain if the Zed is down on compression and thus likely culprit is HG.

Based on the above, I figure borrow my mates compression testing kit first and see how I get on. Thoughts?
Click to expand...
Got to be a cheaper way to start.
Also pop the cap off the expansion tank and see if you're getting a thin stream of water entering the top with the engine running. If not then the water pump could be failing and causing the noise.
And try the WD40 trick on the pulleys too.
Better just check it's not something as simple as a frayed belt.

Oh and add to the list................... is it the vanos pistons rattling?
 
houseofscouse said:
I changed both belts in June when we got her so unlikely that. Will wd40 the pulleys one-by-one now I think.
Click to expand...
Fair enough, but never discount a faulty belt.
 
So.......took the belts off and fired her up....no noise. Spun the water pump pulley and there was my horrid noise.

Couple of hours later and we have a purring cat. No oil in the coolant either. Opened up the oil filter and no water/cappuccino going on there, so now confident the Zed just needs a long run. Hallelujah!
 
Yep - all sorted. Euros had a few in stock...and no...I didn't go for Starline haha.
If that cross member was just an inch further forward...grrr. Jacked the engine up on one side and all good. Bearing had gone in the water pump.
 
houseofscouse said:
Yep - all sorted. Euros had a few in stock...and no...I didn't go for Starline haha.
If that cross member was just an inch further forward...grrr. Jacked the engine up on one side and all good. Bearing had gone in the water pump.
Click to expand...
Aaaand…….. relax 8)
 
Well done OP and Martin!
This forum really is very helpful, excluding myself of course. I'm just here for the beer! :)
 
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