Roar at 2800rpm
 

I recently had a problem with the pulley driving the power steering and the alternator. It had to be towed to a local mechanic and he replaced the pulley and ever since I get this weird noise that 3 local mechanics can't figure out and one if them wants to rebuild the engine. I am convinced this is not going to resolve it. One of them thought it was the turbo and sent it to be serviced which improved the power but the noise is still their. On cold start up she will rev up and not make this noise but as she warms up it growls as you hit 2800rpm and then goes away after 2900rpm, this happens in any gear and is louder the harder you accelerate. It isn't loosing power, I have had them check all the plastic around the fan etc but this isn't the problem either. I am going to send it for a transmission service as its due anyway and one if them has suggested it may be the viscose fan or perhaps a fan clutch relay. Has anyone had this problem or have any idea of what it may be. I do a lot of miles and its driving me mad not to mention causing heads to turn it is that loud.

You first need to tell us what you have (year / model)

Sorry, I am new to this. It's a 2004 e53 3.0D Sport

Did this occur prior to the pulley going out? You can get a roar from the viscous coupling but if didn't have it before then you it typically would not be it. You could check it easily by removing the fan from the clutch and seeing if the roar is still there. Has anyone used a mechanics stethoscope to help isolate the location?

Roar / growl, hard to know as every person calls this differently. If you didn't have the noise before the pulley change - something is different since then.

A few questions: What & why did they change a pulley? Specifically what pulley was replaced, perhaps the idler pulley for the belt that drives the water pump & alternator. If it consistently happens at 2800 rpm, perhaps they didn't tension the belt enough and it is slipping. If so, this is more or a high pitched squeal.

Do you have any issues (and check the fluid level) with your power steering? The comment about a noise from the fan viscous coupling may also be something. Usually the coupling fails in that is never works (no fan noise) or works all the time (lots of fan noise that builds up as your engine RPM's will climb). Did you test the fan clutch?

Noise wasn't their before they pulley was replaced and I am not sure which was replaced I can tell you that the power steering wasn't working and the battery light was coming on. Mechanic is going to disconnect the viscose to check it and he is also going I check the fan clutch plus h is going to change the filters and the fluid in the transmission. Would this be an exhaust issue, the down pipes were replaced last year but never had a problem after that. The car has 132000 miles on it.

Also meant to say that the noise isn't really noticeable when revving in neutral. It only happens when in gear and moving. If I slip into neutral while moving and rev it up it isn't really noticeable either.

If your power steering wasn't working and your battery light was on, these two confirm that your alternator belt (which drives the alt, water pump and power steering) was slipping a LOT or missing in action). There are two additional pulley's to the system that tension the system. He should have checked both to ensure that they spin freely - otherwise you replace with the (new) belt.

How long did you drive it in this condition? Did the engine overheat?

Did your mechanic (now) check the viscous fan drive?

I didn't drive it at all as the power steering was so heavy, it was towed straight away to the mechanic. He replaced the pulley but not sure that replaced the belts or checked the other pulleys. I had picked up on another post that the viscose fan / fan clutch could be causing this and he is going to check it. The engine didn't get a chance to overheat

Did you get your problem sorted? I'll actually be in Belfast next week for business - so I won't have my tools with me :)