S40: Loud noise coming from the engine bay

[rajaii]

Hi Guys,

There was a very loud whining kind of noise coming from the engine bay. Noise is way louder than the engine itself. The noise was coming from the auxiliary belt area. Thought the noise was from the Power Steering Pump, So got a mechanic to look at it. The chap removed the pump checked it thoroughly and said that to his knowledge the Pump and the pulley seemed to be all OK & it might be something else that is making the noise. He is not very familiar with Volvo's, so he didn't want to guess and remove other components and asked me to get advice from someone who has knowledge about Volvo's.

The Steering it is working fine and there was enough oil in the reservoir when he removed it. So is there a way i can check the Power Steering Pump and see whether the noise is from it.

Also while goggling i came across someone saying he had similar problem had got the Power Steering Pump changed, but the problem wasn't solved.

Any suggestion on what other things is should check?

If i can ill later try to get a audio recording of the noise.

[liberate]

hi

if you take off the auxiliary belt and start the car and the noise persists it is nothing to do with the power steering pump - or anything the belt comes into contact with.

[Batfink]

Could be air con compressor pump which is almost directly under the alternator. Mine went recently and both me and the mechanic were convinced it was the alternator, until he took the belt off to change it and discovered it the the air con pulley instead.

Obvously it is only possibly going to be this, if you indeed have air con.

If it is the Air Con compressor be careful with which part number you look at.

[rajaii]

Thank you guys for quick reply.

I will try to start the car and see if the noise is gone or not.

If the noise is gone then the problem should be in the components running on the auxiliary belt. How do i check all the pulleys and components that run on auxiliary belt (Power steering pump, Alternator & Compressor) to see which is making the noise?

[liberate]

there are people on here who really know their stuff: ) but here's what i'd try.

whilst the belt is off check all components are securely bolted on to relevant brackets.

using your fingers check for excessive play on bearings of all pulleys on all components that have contact with the auxiliary belt. lots of play equals a possible problem

put on a new auxiliary belt it should have very little movement, pull push with finger, up or down (5-8mm). if it is loose change the belt tensioner.

turn steering wheel with engine running - does noise change? (if yes = suspect part)

turn air con with engine running - (does not work?) does noise change? (if yes = suspect part)

send in audio of noise

[jez v40]

my guess is alternator pulley. do search on here and you'll find loads of posts about it .

[mjbv40]

You can use a longish breaker bar as a sounding rod for a lot of the components; that's how I discovered the bearing noise on the alternator on my old 406.
For God's sake be careful when you do it, needless to say it's a dangerous game. Keep well clear of the belt!

[happy diver]

http://www.ebay.com.au/itm/271200715...84.m1423.l2649

[Dog_Book]

Does the noise go away if you turn the engine off?