M54 3.0 sounds like a helicopter :(

[Matty_Z4]

I recently replaced the lower intake boot as there was a small hole in it and since I have done this the car occasionally seems to sound like a helicopter?
I have checked the fault codes with Carly and I just get a 00000 (No fault betatet) so I guess I need to plug in INPA/ISTA and see if I can get some codes pretty sure the only one will be cant communicate with CD changer (Carly picks that up as an unknown fault) I will report back later after I have plugged my laptop in.

I have tried to get a video of the sound and I think it gets worse when the AC is turned on so wonder if its the AC clutch/pulley or something.

[youtube]QJz33CuqP48[/youtube]

Any car wizards out there recognise the noise? I have checked the oil and it looks ok.

 

[j3nks79]

Sounds like a tensioner. Take the belt off start the engine and see if noise goes.
If it does spin the pulleys/tension ac compressor to work out which one is the problem

 

[smorris_12]

Sounds to me like the belt flapping in the breeze due to a weak tensioner.

 

[Matty_Z4]

Thanks guys, Looks like I will be taking the belts off for an inspection later on then. Doesn't look too difficult to do and everything seems to be accessable from the top winner winner.

 

[Matty_Z4]

Well it seems that we have a ghost in the machine. Took the belts off to check the pulleys and everything felt find no play in any of the pulleys and the tensioners felt pretty strong still. The AC belt has a couple of wear marks (see photos) but doesnt look damaged or in need of a replacement. The main drive belt looks ok also (to my uneducated eyes).

Is it true that you are supposed to replace the accessory belts every 4 years (it seems wasteful?) Mine were last replaced 13/05/2019

With your engine cold and turned OFF, inspect your drive belts for wear. The belts should be free from cracks, fraying, glazing and missing chunks. Replace belts if any of the previously mentioned issues are present or every four years.

https://www.pelicanparts.com/techarticles/BMW-X3/35-ENGINE-M54_6_Cylinder_Drive_Belt_Replacement/35-ENGINE-M54_6_Cylinder_Drive_Belt_Replacement.htm


Noise seems to be gone, (Excuse the high pitched exclamation/surprise that the noise was gone all I did was take it apart and put it back together again)
[youtube]GBtYGxxFJOA[/youtube]

[youtube]Npq4AS4lODg[/youtube]

Pics of the AC belt, main belt photos to follow (iCloud is being a Sh1t today)

 

[smorris_12]

Is it true that you are supposed to replace the accessory belts every 4 years (it seems wasteful?) Mine were last replaced 13/05/2019

I concluded that poly V belts are basically indestructible in the 00s. I changed the belt in my E36 325i and the old one was so good I kept it. I've never bothered going near my 54 plate 320d belt and it's still fine at 280-odd k miles. Four years sounds like a recommendation from someone who makes belts!!

 

[Matty_Z4]

Is it true that you are supposed to replace the accessory belts every 4 years (it seems wasteful?) Mine were last replaced 13/05/2019

I concluded that poly V belts are basically indestructible in the 00s. I changed the belt in my E36 325i and the old one was so good I kept it. I've never bothered going near my 54 plate 320d belt and it's still fine at 280-odd k miles. Four years sounds like a recommendation from someone who makes belts!!

It did seem like a strange recommendation, I have never had to change an accessory belt in any of my cars bu this is the first one over 10 years old. Good news that my belts are still in good condition, its odd that the noise is gone just by taking things apart and pitting then back together. I was expecting to feel some play in one of the pulleys or one of the tensioner springs to feel weak/play in them.

Now iCloud has done its thing this is what the main belt looked like.

 

[Matty_Z4]

Well the noise is back with an additional rattle, I think I am going to have to have this looked at professionally as the rattle noise has triggered my paranoia and am hoping and praying its not what I think it is.

The helicopter noise appears to be coming from the front of the engine, but now after hearing the rattle this morning im not so sure. The rattle sounds like a stones in a tin of beans, now I had that noise when I first got the car but it was much worse and was followed up with other symtoms like needing to use lots of revs to move off and the rattle was pretty much there most of the time. That turned out to be the torque converter damn expensive fix. Now I am hearing a similar noise and I really hope this one is not on the way out after 5 years and less than 20k miles.

Why the sudden paranoia, well when I checked the belts the other day I noticed that one of the pipes to the transmission cooler? looked damp/oily So I am wondering if there is a very slow leak as there doesn't appear to be any fluid pooling in the under-tray or any active drip I did give the cooler a clean off in April as it looked very grubby and wasn't sure if it was leaking now im pretty sure I need this looking at

Any idea how much the two pipes from the gearbox to the cooler cost and is it work getting the cooler replaced at the same time as the pipes?

 

[smorris_12]

M54? Stones in a tin from the front of the engine is a classic description of VANOS troubles.

I wouldn't say the grubby oil cooler lines are significant. They're not wet so, if the push-fit is leaking, it's an infintesimal amount.

 

[Matty_Z4]

M54? Stones in a tin from the front of the engine is a classic description of VANOS troubles.

I wouldn't say the grubby oil cooler lines are significant. They're not wet so, if the push-fit is leaking, it's an infintesimal amount.

I think I would prefer it to be the Vanos than the TC again, I have had a Vanos rebuild kit sat in my spare room for a couple of years just not had the time/courage to give it a go for fear of messing up. Was going to post a shout out on the forum in the spring to see if there is anyone on the forum local (West Midlands Shirley/Solihull (ish)) who has done this before and would be willing to help/supervise for a couple of crates of beer (or adequate compensation). Assuming the gaskets dont degrade just by existing.

The rattle doesnt appear when stationary only when driving, it is very occasional and cannot be reproduced consistently starts at about 1500rpm and stops somewhere near 3k rpm.

I think I would agree with you the one cooler line that appears to be leaking is not wet to touch just mildly damp and there is nothing on the under tray suggesting a drip so I think your right its only weeping. I had a look to see how much the lines are and they are £100 each and the cooler is £50 so a smidge expensive just to change it for the sake of it.

Do we think the helicopter noise and the rattle is related or am I doing the old thing of going well 2 + 2 must = 5

Ive got about 2 - 3 weeks before its going in for the MOT and Service so if there is anything I can check between now and then that would be awesome if not I will ask for them to look at it when they service* the car.

*Yes I could do it myself but I like the stamp in the book and I think its a good idea to have someone who knows what they are doing look over the car.

 

[smorris_12]

Get yourself a long screwdriver and use it as a stethoscope. Works ever so well. That should help to see if the helicopter is inside the cam cover along with the tin of pebbles.

I still think it sounds like the belt flapping - while the tensioner will feel strong, they do age and, particularly, wear. When they're worn they tilt the pulley off axis causing the belt to travel across it at an angle. This eventually results in a squeak as the rubber is pulled across the plastic rather than running squarely so I can imagine it can also generate an oscillation in the belt

 

[DMike]

Did you try starting the engine without the belt on, as j3nks79 suggested? You cannot run the engine for long without the belt, but helps to narrow down. Noise gone, time to change belt tensioner, pulleys etc.

 

[Matty_Z4]

Get yourself a long screwdriver and use it as a stethoscope. Works ever so well. That should help to see if the helicopter is inside the cam cover along with the tin of pebbles.

I still think it sounds like the belt flapping - while the tensioner will feel strong, they do age and, particularly, wear. When they're worn they tilt the pulley off axis causing the belt to travel across it at an angle. This eventually results in a squeak as the rubber is pulled across the plastic rather than running squarely so I can imagine it can also generate an oscillation in the belt

I think I will keep the screwdriver trick in the bank lets see if we can solve one noise at a time then

Is there any way to test the tensioner to see which one is gone or as they are only £50 just replace both of them? I can get the main belt tensioner today and the AC belt tensioner I can get by Tuesday from GSF. Do I need the idler pulleys as well?

Idlers?
https://www.eurocarparts.com/p/ina-drive-belt-guide-deflection-pulley-326110060
https://www.eurocarparts.com/p/ina-drive-belt-guide-deflection-pulley-326110070

Tensioners.
https://www.gsfcarparts.com/za029191
https://www.gsfcarparts.com/za029230

I may just get the main belt tensioner today anyway and see what happens.

 

[Matty_Z4]

Did you try starting the engine without the belt on, as j3nks79 suggested? You cannot run the engine for long without the belt, but helps to narrow down. Noise gone, time to change belt tensioner, pulleys etc.

No I didnt run the engine with the belts off, but I did take them off and inspect and the noise went away only to come back the following day + the additional rattle.

 

[smorris_12]

Is there any way to test the tensioner to see which one is gone or as they are only £50 just replace both of them?

I'd start with the main one. If they're the same tensioner (I'm an optimist) then you could always swap them about.

 

[Matty_Z4]

New tensioner done and the helicopter noise is still there, take the belts off and gone but comes back with only the main drive belt on. So I think the next step will be the idlers? starting with the top one as that is easiest to do?

 

[Matty_Z4]

Some shiney bits arrived today, installed them quickly and it no longer sounds like a helicopter. No idea which idler was the problem just did both.

 

[enuff_zed]

Some shiney bits arrived today, installed them quickly and it no longer sounds like a helicopter. No idea which idler was the problem just did both.

Good news!
So as I have a car incoming for the same kind of noise, do you think it was worth changing the tensioners or just go straight for the iddler pulleys?

 

[Matty_Z4]

Some shiney bits arrived today, installed them quickly and it no longer sounds like a helicopter. No idea which idler was the problem just did both.

Good news!
So as I have a car incoming for the same kind of noise, do you think it was worth changing the tensioners or just go straight for the iddler pulleys?

It makes sense to do the tensioner at the same time as you have to take off the top idler to get to the tensioner bolts. In an ideal world it would be good to know how to check/test them and only replace what is needed.

Mine had no visible wobble or any signs to an untrained eye which one was on its way out.