What's this noise?

[Stuart]

I have had a May 2003 D5 XC70 since November, which now has 18,000 miles.
Over the weekend I thought I heard a ticking noise when the car was at idle, put the bonnet up and was surprised how much louder the ticking became relative to the engine noise. It seems to be coming from the power steering pump area and is a comparatively slow rate of ticking, somewhere in the region of 1 - 2 per second at idle, and does increase when the engine speed is raised but not proportionally. At that rate it is clearly not related to pulley rotations, and I have looked carefully to see if it could be per belt complete rotation or something like that but can't see anything wrong with the belt.
I was wondering if it's something like a pulsing of a pressure relief valve?
Anyone got any ideas please? I don't remember hearing it before these last few days, but then again I haven't had the engine running with the bonnet up before that I remember.

[Prepo]

I have had a ticking noise for a long time and it is noticeable when the engine is idling. My friendly service man has repeatedly told me that it is not an engine noise and is nothing to bother about - I forget where he said exactly the noise was coming from but some sort of pump and this is normal, apparently. If you are able to get a specific diagnosis I would be interested to hear about it.

[Stuart]

It seems to be less significant when the engine is hot.
I'll let you know what it is when I find out!

[Stuart]

Noise seems to have disappeared for now. no idea what it was.

[TrueBlue]

Probably getting deef - caused by all the noise generated by your flapping flag (HeHe).

[Stuart]

As one flapper to another :p

[AWD*V70XC]

Would the noise be something to do with the A/C that many people refer to as 'like a ticking clock' when inside the car. It might just appear to be coming from the another area as noise origins can be deceptive.

[Stuart]

Thanks for the A/C thought. The noise does seem to have disappeared now, for whatever reason, but I will bear it in mind.

[Joy Driver]

I had my driver window open the other day and when I started the engine, I heard a consistent ticking (2 per second) coming thru the window. I could not hear it inside the car. I left the car idling and opened the hood and it was a bit louder and appeared to be coming from below the oil dipstick. After backing out of the driveway, the ticking stopped, approximately 30 seconds later. After my first stop, I restarted the engine again, and the ticking was gone. Appears when the vehicle is warm, it goes away. It is not the single ABS tick that is heard at 12 mph. It is not coming from the vents, a/c, dash or steering column, as I have read in previous posts.

I'm hoping this is as simple as metal heating up. MY 2002 and I've had it since new. I usually never have the windows open upon start up, so perhaps that's why I've never noticed the ticking in 4 years?

Car has been great so far. 55,000 miles. I had the transmission fluid flushed at 35k, and will do it again at the end of this summer. I get very sporadic delay and thunk from Reverse to Drive, but then it'll go away for a week or two, then come back for a couple days etc...Fluid is still reddish and transparent.
Still on original brake pads and they still look good for 6 more months. I haven't done any other fluid changes, other than oil. I'll probably do the brake fluid this summer too. I get 24-26 mpg on my 10k Triple Treads consistently.

Let me know if anyone else has noticed this ticking sound. Thx. JD

[Joy Driver]

Seattle Eastsiders,

What Independent Volvo Shops would you recommend. I've had all service done at Ravenna to date and I've been very happy with them. But now that warranty is up, perhaps I'll switch to an indie for oil changes.

thx.

[shawn_75]

I've noticed that the mass airflow sensor makes a ticking noise as described on occasion. The only time I notice it is when starting the car to back it out of the garage and immediately shutting it off. The MAF sensor will tick for about 15 seconds after I shut the car off.