Need help identifying resonance noise

hazchem69 · Dec 8th, 2021, 16:19

Looking for ideas as to the cause of a strange resonance noise I'm getting from my engine when it's revs are at around 1k rpm

It's not present at idle or over about 1100 rpm I initially thought it was the power steering pump as it had started leaking. But I've replaced it and the noise is still present. I do believe it's to do with one of the components connected with auxiliary belt as no noise when belt removed. But all pulleys and tensioner feel OK.

I've attached short video with the noise, can be heard over general engine noise as a deep resonance
Any ideas gratefully received

2003 v70 2.4 petrol auto 54k miles so hardly run in !

stuart bowes · Dec 8th, 2021, 16:51

I've heard alternator pulleys can be a common point of failure? I'm sure someone will be along soon with a more definite answer or a way to test it

myfirstv70 · Dec 10th, 2021, 16:34

If its a harsh clatter that goes with revs then its the above....mine gave up at circa 120K....
HTH,
Nobby

hazchem69 · Dec 15th, 2021, 07:59

I have been able to confirm the problem is the auxiliary belt tensioner. Even though the car has only done 54k miles from new, I guess age has taken its toll and the tensioner is just that bit weaker than it was when new.

Georgeandkira · Dec 15th, 2021, 17:01

The spring inside can weaken but I bet the grease in the pulley bearing has dispersed or hardened.

The pulley is available separately but many advise not to bother and just buy a complete tensioner. It's what I did with my '02.

My '07 w123K and my '05 truck, w only 53K are both idling loudly.
I have the "auxiliary drive belt refreshment kits" on order.

Are "Gates" brand parts available in the UK? I ask because the Gates tensioner I bought was made in Canada. It installed perfectly.

....and when do these maintenance tasks rear their noisy heads? When the weather turns colder, just like old U-joints in a driveshaft.

Millie20 · Dec 20th, 2021, 22:37

Yes Gates is available here. I just did this job last week, but opted to pay the premium for the blue box.

Just to note, it is infinitely easier to get the bottom bolt of the tensioner through the wheel well.

Dec 8th, 2021, 16:19	#1
hazchem69 New Member Last Online: Jan 2nd, 2022 22:45 Join Date: Jan 2013 Location: dorking	Need help identifying resonance noise Looking for ideas as to the cause of a strange resonance noise I'm getting from my engine when it's revs are at around 1k rpm It's not present at idle or over about 1100 rpm I initially thought it was the power steering pump as it had started leaking. But I've replaced it and the noise is still present. I do believe it's to do with one of the components connected with auxiliary belt as no noise when belt removed. But all pulleys and tensioner feel OK. I've attached short video with the noise, can be heard over general engine noise as a deep resonance Any ideas gratefully received 2003 v70 2.4 petrol auto 54k miles so hardly run in !

Dec 8th, 2021, 16:51	#2
stuart bowes trying to be helpful Last Online: Today 00:20 Join Date: Aug 2020 Location: Dagenham	I've heard alternator pulleys can be a common point of failure? I'm sure someone will be along soon with a more definite answer or a way to test it __________________ V70 '01 auto petrol 2.4 (140) 70k ------------------------- mini project - link

Dec 10th, 2021, 16:34	#3
myfirstv70 Senior Member Last Online: Apr 24th, 2024 17:24 Join Date: Dec 2008 Location: Lincoln	Alternator Pulley If its a harsh clatter that goes with revs then its the above....mine gave up at circa 120K.... HTH, Nobby

Dec 15th, 2021, 07:59	#4
hazchem69 New Member Last Online: Jan 2nd, 2022 22:45 Join Date: Jan 2013 Location: dorking	I have been able to confirm the problem is the auxiliary belt tensioner. Even though the car has only done 54k miles from new, I guess age has taken its toll and the tensioner is just that bit weaker than it was when new.

Dec 15th, 2021, 17:01	#5
Georgeandkira Premier Member Last Online: Yesterday 14:34 Join Date: Feb 2009 Location: Hackensack	The spring inside can weaken but I bet the grease in the pulley bearing has dispersed or hardened. The pulley is available separately but many advise not to bother and just buy a complete tensioner. It's what I did with my '02. My '07 w123K and my '05 truck, w only 53K are both idling loudly. I have the "auxiliary drive belt refreshment kits" on order. Are "Gates" brand parts available in the UK? I ask because the Gates tensioner I bought was made in Canada. It installed perfectly. ....and when do these maintenance tasks rear their noisy heads? When the weather turns colder, just like old U-joints in a driveshaft.

Dec 20th, 2021, 22:37	#6
Millie20 Member Last Online: Nov 24th, 2023 08:21 Join Date: Sep 2020 Location: Oxfordshire	Yes Gates is available here. I just did this job last week, but opted to pay the premium for the blue box. Just to note, it is infinitely easier to get the bottom bolt of the tensioner through the wheel well.

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