I have had this hissing sound coming from the passenger side (right side) of the engine bay ever since I've had my '07 XKR, but I always assumed it was normal. Today it occurred to me that it might not be normal and could be the source of one of my random cold-weather noises.

This noise happens whether the car is hot or cold, though. In this video, the car is hot.


So is this a normal sound? I could not immediately find a source of this hissing sound...

 

Dunno (it's night here, and I'm not venturing out ). But here's an old trick for finding the specific source of sound: take a length of flexible hose, stick one end against your ear, & move the other end around the suspect area. You can often pinpoint the source within a few mm.

 

Good idea.

I should also note that the sound cannot be heard with the hood closed.

 

So I take it it's not normal? I'd rather not go poking around in there today since we're having a nice soaking rain all day.

 

I haven't heard any hissing under my bonnet, but mine's a 5.0, and I've seldom run it with the bonnet up.

 

That aint normal.

 

Thanks for the confirmation. I thought it might not be normal. I will investigate more tomorrow. Hopefully it just needs a new tube of some sort...

 

Mine certainly does not sound like that. It does sound like a leak but you would think an error would occur with a sensor.

 

I would've thought the same thing. I have no CELs. However, on cold days when the engine is cold, idle can be quite rough. Blipping the throttle from idle will result in RPMs dropping below idle temporarily until the ECU kicks it back to the correct idle speed. Funny, I never thought anything of it until yesterday!

Also, I have this annoying sound that happens when the car is cold.


I (nor the dealer) was able to ever figure out the source of this sound so I just gave up and chalked it up to that lovable Jaguar character. It could definitely be related to this intake leak, I'm thinking!

 

Down here in New Mexico, the Diamondback rattlers love to hide in cars. They also "hiss" allot when annoyed and getting ready to strike. Be careful, they are hard to find, and it always sounds like the "hiss" comes from the right side of your body.

Hope you find the source, .....and soon.

 

Haha! I don't think we have many snakes here. But we do have rabbits, mice, rats and other vermin!

I am hoping to change the engine air filters soon since I have never changed them. Could it be possible that the air filters are so clogged that some air is being sucked from other places in the intake because of the vacuum? I would definitely think that would cause a CEL, though.

 

Might be past the MAF, perhaps the throttle body plenum? It is easy to remove the intake tube. You could also try a smoke test.

 

The hissing sound is normal. Its always on the right side of the engine exactly where you are poking around in the video, not sure what part it comes from. It did this in my 2008, 2011, and my latest 2013 XKR.

In the second video I assume you are referring to the higher pitched whining/whistle noise? Before I bought my 2013 earlier this year the dealer let me take it home for the night to really listen for things since they know Im "sound sensitive"... I heard a similar noise in my garage (can hear it anywhere now if I really want to listen for it). When I brought it back the dealer put it on a lift for me and pinpointed exactly where its coming from. Under the car where the exhaust pipes meet probably about 2/3 back if my memory is correct. Its pretty loud and clear where it comes from when you get next to it. You can even hear it while sitting next to the car just in front of the rear wheels. Was told there is nothing wrong, just a characteristic of this particular car. I almost passed on the car because of it, but ultimately decided to buy it a week later.

Have your dealer throw it on a lift for you one day to see if its the same sort of thing.

Not to hijack your thread, but there is another noise that has always bothered me and I wonder if anyone else has experienced it. It did it some in the 08, 11, and more so in the 13. When you accelerate (light or heavy) and lay off the gas to coast, there is a whining/winding down noise that can be heard, its faint. Ive rolled the windows down to see if I can hear it and I cannot, only when the windows are up. If anyone has experience with this, please let me know what causes it.

 

I thought the hissing may have been normal, because I recall my X350 having a similar hissing sound.

Very interesting what you said about the exhaust. That noise seems to happen most at a particular RPM (and only when cold weather), so maybe at that RPM there is a certain resonance that causes that noise.