ST JAMES

I i'm looking to replace or update my tensioner and pulleys because I hear squealing and squeaking around those areas. If I were to buy https://www.fcpeuro.com/products/bmw...-11287512758-1 https://www.fcpeuro.com/products/bmw...x3-11287516847 https://www.fcpeuro.com/products/bmw...ly-11281427252 BMW E60 525i M54 2.5L Engine Drive Belts - 11281706545 - Racing Accessory Belt - Alternator/Water Pump/Power Steering Belt - ES#2836654 These 4 things would it eliminate the squeal and possibly make the my m54 (e60 525i sport) run better? Are there any upgrades for the pulleys and tensioner besides replacements? Thanks!

I'm thinking that since I haven't changed my valve cover gasket there's also an oil leak that could also be causing my rpm to behave incorrectly while accelerating due to incorrect air and sludge building up in my intake manifold. (I think I read something somewhere about the air system of the m54 not acting right due to oil leaks) Could this be causing my tensioner and pulleys to wear out faster due to the engine/rpm jerking?

KyleB

BMW 'upgraded' the belt tensioners from a purely mechanical design (i.e. spring loaded) to a hydraulic design. In my opinion the mechanical design is tried and true, and I always replace mechanical with mechanical. That's just me however, there is nothing wrong with the hydraulic design. I'd replace your tensioners with whatever ones are on there now.

I've never had good luck with Gates belts. I've had a few brand new Gates belts squeal in years past. I always use Continentals. I don't know what their idea of a 'racing' belt is. Sounds hokey to me.

Your tensioners are not connected to the oiling or air intake systems in any way shape or form. M54s are prone to valve cover gasket leaks. If yours is old, yes it's probably leaking. It's probably leaking oil from a few other areas too. There are two kinds of M5X motors...those that leak oil now, and those that leak oil now. Wait, I guess there's only one kind.

Your hesitation when accelerating could be due to so many things it would be impossible to point you in any direction without more information on what's been replaced recently, any fault codes you're retrieving, etc etc.

Good luck with the car.

twh

Contitech has a kit with all the parts needed for a decent price. All same OEM suppliers as BMW uses in the car.

KyleB

Contitech is the OE supplier for the belts, and I believe INA is the OE supplier for tensioners and pulleys.

twh

Yes. The Contech Belt/Tensioner Kit for my N52 engine had a Continental belt (made in Germany) and an INA tensioner and an INA idler pulley.

ST JAMES

Thanks guys. Yea I was reading around about that gates belt and the teeth have been messing up. There's a regular gates belt on my car right now (past owner). Looks like i'm going with the Contitech kit.

About my oil leak affecting the tensionser: I usually try to see problem relationships between parts. I read some where that the m54 has a strong vacuum so when the valve cover gasket goes bad and leaks the engine will vacuum in unmetered air through that leak causing abnormal amount of air in and build up sludge into the intake manifold. I would assume this would cause abnormal airflow and rpm behavior causing the engine/rpm to jerk, bounce, etc during acceleration. The jerking behavior of that oil leak problem of the engine is where i'm thinking the tensioner/pulley problem is related. Since the engine is jerking all the time it puts abnormal stress/torque patterns on the pulleys, tensioner, and belts causing them to fail faster than normal. Correct me if i'm wrong.

I should hurry and get that valve cover gasket replaced. I hope my car will hold up till next week. I drive a lot and i need to wait for the parts to be shipped. I heard the noise about a week ago. It dissapears SOMETIMES.

twh

BTW, my Contitech kit for my N52 has a loose piece of paper in it that says to delete the sheetmetal washer on the back of the idler pulley. That washer also serves to hold the bolt to the idler pulley before it gets installed. When I took off my original pulley, that washer was there on the original part. I also got out my micrometer and that washer should not be deleted by my measurements. Anyway, I put it on and ignored the loose piece of paper and have had no issues in the last couple months since I put it on. The original parts that came off looked identical to the kit parts.