I just bought a 2007 xc90 v8 from a private seller in seemingly great condition, however, now that I've driven it around for a bit I am noticing a heavy rattling noise coming from what sounds like the top left side of the engine. I also noticed it is leaking a good amount of power steering fluid. I will post a link to my video of the noise. If there's already a thread on this issue I apologize, but I couldn't find it. Please let me know your thoughts. I'm good with cars so I want to avoid a diagnosis from a mechanic unless its absolutely necessary. Thanks in advance!

https://youtu.be/PpThrQjcGSI

 

I’d say the power steering pump is bad or low on fluid

 

WOW - what a noise!

Could be a bad balance shaft bearing - If it is and not the steering pump - don't drive the car, if it comes apart you total the car!

https://www.swedespeed.com/threads/t...g-s-v8.202205/

Also the serpentine belt idler bearings make bad noises also -

 

Great, thanks guys! I'll start with the power steering pump. I've been searching but theres little information on the v8 engine as far as this type of noise. I suspect it may also be the water pump. I am praying it is NOT the balance shaft bearing. I've read that's ususally only a problem on the 05 v8's. Any known truth to that? I'll update soon, thanks.

 

In the short video, I didn't notice much engine vibration, although there was considerable amount of noise. The engine, at least based on a lack of visible vibration, appeared to run smoothly. Before removing and/or replacing things, my advice would be to first check the exhaust pipe connected to the exhaust manifold to see if it's hitting anything. Try an old-school method ... BEING VERY CAREFUL ... With the engine running, use a very long screw driver, place the tip against various areas of the engine, with you ear close to the other end. Check various areas to detect where the sound is greatest. This will, at the very least, help you to localize the source of the sound. I know this isn't "high-tech", but it has worked for me in the past to locate the source of engine noise.

PS: Curious. When you opened up the oil cap on the value cover, how did the oil look on the valves. If it's full of sludge, it might be possible that the value lifters are sticking. Here's a video that illustrates valve lifter noise.

 

That's a great tip thanks! I would have never thought of the exhaust manifold being loose, is that a somewhat common issue? I think it's internal because as the engines revs up the noise speeds up as well. Doesn't necessarily get louder, it just increases in speed, so that leads me to believe whatever the noise is coming is spinning. I also read somewhere that the intake damper sometimes comes loose in these models. I'll upload some pictures of what I find. Hopefully it's nothing major. 🤞

 

Doubt the exhaust manifold pipe may be loose, but something else may be loose that's rubbing up against it. Anyway, good luck in find the problem ... keep us posted.

 

Hey guys, still trying to figure this one out! I've decided to do an engine overhaul since this motor already has 170k so I am so far as to having removed the plenum and serp belt, but now since I can't turn on the engine I don't know where the noise is coming from. I have another video of the noise that I'll attach a link to but I've been doing some research and on swedespeed.com someone with a similar noise figured out it was their intake plenum damper flap (idk if thats the technical name) and its supposed to be an easy fix. I also broke off the bolt used to loosen the pully tensioner so I think replacing everything is my best bet at this point. any tips on what should be replaced and what I can save some money on? Thanks in advance

Heres the second video of the noise:

 

Wow - sounds like a train running along tracks. Hope you sort it out!

 

You just bought it - don't you want/need to drive it?

There's a big difference between an "engine overhaul" and possibly just replacing the idler bearings on the front of the engine or a power steering pump!

 

Kinda, I currently drive a 2001 Altima and this is a bit of an upgrade for me, and because I got a really good deal from a private seller and the car has 170k on it, a leaky PS pump and a horrid noise coming from inside the engine, I want to clean it up and replace any pulleys, bearings and gaskets that may need replacing while I have it open. I've rebuilt engines in the past but this is my first time working with a volvo engine, much less a v8. I've found videos and threads with sounds similar to this one but nothing quite like it. It sounds like a train on tracks as someone previously said. Maybe a timing chain? I'm in Connecticut so I havent opened the hood in a few days since I don't have a garage and its currently freezing. I will probably get back under the hood on Monday (my day off) and give an update. MY speculations are the valve timing chain, water pump, or the dreaded counter balance shaft, however I keep reading that there have been no reported issues of the counter balance shaft issue on the 06+ models and mine is a 07.

 

Any updates on this issue. I think I am having the same issue?