N54 engine noise

[Geojoe3333]

Anyone have an idea of this noise and what it could be? Seems to quiet down when the car gets warmer but it is loud at 1st. I'm thinking clean oil might fix it but the oil in the car is good, it's just been sitting a while. The car has 45000 miles on it and it's a 2008. It sat for three years only putting 300 miles on it in that time. It sounds like plastic on plastic and it's coming from underneath the engine cover. Any ideas are welcome. Thank you all.

[Dackelone]

Ohhh... that sounds BAD!! I think it could be your timing chain pensioner or one of the chain ramps that the tensioner pushes up against it. I would have a professional listen to that sound clip.

Change the oil and see how it sounds. But I would not drive the car. Oil that's three years old isn't good for the motor.

Dack

[Geojoe3333]

Originally Posted by Dackelone

Ohhh... that sounds BAD!! I think it could be your timing chain pensioner or one of the chain ramps that the tensioner pushes up against it. I would have a professional listen to that sound clip.

Change the oil and see how it sounds. But I would not drive the car. Oil that's three years old isn't good for the motor.

Dack

I plan on getting it looked at before I make it a daily driver again, but like a said it's been sitting for the last three years. Never sounded like this though and I don't understand how just sitting there this happens... thank you for the advice

[Dackelone]

Originally Posted by Geojoe3333

I plan on getting it looked at before I make it a daily driver again, but like a said it's been sitting for the last three years. Never sounded like this though and I don't understand how just sitting there this happens... thank you for the advice

You should change all your fluids(brake, trans, diff, engine oil, coolant, PS fluid). Really. You probably need for new tires too.

Have the car towed to a shop and see what they think it is. IF it's the chain tensioner... that's gonna be big buckO's... plus the trans has to come off to get back there.

When you change the engine oil.. look for bits of plastic from the chain tensioner ramps.

Dack

[Geojoe3333]

Originally Posted by Dackelone

You should change all your fluids(brake, trans, diff, engine oil, coolant, PS fluid). Really. You probably need for new tires too.

Have the car towed to a shop and see what they think it is. IF it's the chain tensioner... that's gonna be big buckO's... plus the trans has to come off to get back there.

When you change the engine oil.. look for bits of plastic from the chain tensioner ramps.

Dack

Seems like the car would run a bit rough if the tensioner was bad because there would be some slack in the chain. The car doesn't hiccup or anything while running, in fact it runs pretty strong. 🤷🏽*♂️

[Ric in RVA]

Does it sound louder with the oil fill off?

You might even catch a glimpse of tensioner material peering in there.

[Geojoe3333]

Originally Posted by Ric in RVA

Does it sound louder with the oil fill off?

You might even catch a glimpse of tensioner material peering in there.

I haven't tried running it without the oil cap on, but I will give a look in there

[iminhell1]

I'm going a different direction ...

Bad alternator pulley.


Test, remove belt and I'll bet noise goes away. Spin each pulley by hand and you should be able to feel which is bad. Alternator should only spin one way, you'll feel it lock if you try the other way.

[Geojoe3333]

Originally Posted by iminhell1

I'm going a different direction ...

Bad alternator pulley.


Test, remove belt and I'll bet noise goes away. Spin each pulley by hand and you should be able to feel which is bad. Alternator should only spin one way, you'll feel it lock if you try the other way.

Well that sounds better than a bad chain tensioner. I'll give it a shot, thank you.

[Mr Gasser]

Take off the belt and run it. See if the sound goes away... if so it's an accessory that's bad.

[Geojoe3333]

Originally Posted by Mr Gasser

Take off the belt and run it. See if the sound goes away... if so it's an accessory that's bad.

Im going to try that, I think part of the 45k maintenance it actually replacing the belt. Running the car without the belt won't hurt anything will it?

[Geojoe3333]

Think I can replace the pulley without taking off the entire alternator?

[Mr Gasser]

when I say run the engine without the belt, that only for a few seconds to confirm, here is a writeup on the idler pulley system for yours and mine's car.
http://my1series.com/2015/03/23/bmw-...e-belt-issues/

you may need a belt idler pulley kit that has all the pieces...

[Dackelone]

Originally Posted by Geojoe3333

Seems like the car would run a bit rough if the tensioner was bad because there would be some slack in the chain. The car doesn't hiccup or anything while running, in fact it runs pretty strong. ����*♂️

Nope, that's not true.

At least on my e39 540i... I had the chain ramps fail... the engine ran smoothly... but as the rpm's increase the engine would surge, the ECL will come on(sometimes), bc the cam timing can't stay within specs/phase. Also at idle it made the same type of noise as in the OP's video.

On my 540i 6sp... it went from making no noise to a ton of noise... like someone threw a light switch. I just parked the car until I could replace the chains, ramps, tension, all the front seals and gaskets and water pump, etc. It was a really big job on that V8.


Change your engine oil often and not once every year like BMW says. The best oil is fresh oil.

OP - I think removing the polly ribbed belt is a good idea. At least you can eliminate that area if the noise stops. Just don't run the engine for more than a few minutes. Remember your water pump will still run, bc it's electric.

Dack


Oil pan removed... all the broken plastic bits from the chain tensioner ramps.

[Geojoe3333]

Okay so I finally got to the bottom of this, took everything apart and replaced the Alternator. The noise ended up being the bearings inside the alternator, not the actual pulley. So I got a refurbed alternator and put a brand new pulley on it. Also did the oil change, radiator fluid change, serpentine belt, air filter and cabin filter and crankshaft sensor(was getting a code for it). This thing is running perfectly now. Plugs and new battery to come.