OK,
We have had our 04 se7 for just over 3 months now.

I did my homework, got a low Kilometer (Canada) 69,000kms dealer serviced sweetheart with more servicing done than kms on the odometer.

So baseline is set. She's in amazing shape.

I need to set apart the SAI issue once and for all.

When the car starts cold we get the high pitch sound (from outside of the car) that goes away after a short while (30 seconds)ish.

On occasion (hot or cold) on the inside of the car, a random sound of a turbine slowing down makes my wife and I look at each other with the look of - what the heck was that?

- It does not sound like a hair dryer
- It does not sound like a vacuum

outside - It does sound like a balanced continuous high pitched hum and then goes away.
inside - Sounds like a turbine slowing down

Is the slowing turbine sound inside the cabin simply the inside sound of the SAI pump turning off?

Other explainations of how the SAI sounds are throwing me off and nowhere have I seen anyone comment conclusively on the interior sound the pump makes if any.....

I am due to track down the thread that shows the step by step process to replace the filters (if anyone has that link I would greatly appreciate it) so that will be taken care of this weekend.

My appreciation in advance,

Paul.

 

Most likely is that sound. You could unplug the pump, see attached pix, or the air injection pump relay inside the underhood fuse box. Then crank the cold truck. No whining (from the pump, as well as SWMBO) is a good thing. Or you can press a stick or long screw driver against the pump, and your ear to the other end, and listen to the pump (they also make a mechanic's stethoscope for this).

Doubt the filter change would do much for the motor bearing in the pump once it starts making noise. A dismantler, especially one in the California area, might also be a source for a used pump. Taking pump apart and oiling with very thin penetrating oil might help, for a while.

If not this, then it is the flux capacitor charging up, and if you press the correct sequence of buttons on the radio you will time warp back to the music of the 60's!

 

Easiest way is open the hood, start it up and go to the SAI. The rivets stretch over time and a gap opens up for sound/air to escape. you can squeeze the housing together and see if the noise changes. I just unplugged mine cause it started to get REALLY loud after a few months. you could drill out the factory rivits and install nut/bolt replacements ive been told, or buy a new one or jsut leave it unplugged. if it is that though and you unplugg it, id unplug the actuators for the system too, otherwise you will have exhuast gas shootin back into the sai pump and slowly melt it everytime the thing tries to run! the truck will sounds pretty good too for the first 30 seconds haha

 

Sounds like another job for high temp RTV.....

 

So is the sound it makes the bearings in the pump?

I never thought it would be so loud in the cabin.
Initially I thought it was the a/c fan slowing down or the compressor shutting off or something.....

If it is the flux capacitor I'll dial it back to 1945 and buy all of Malibu!

THanks.

 

Pump noise could be bad bearings, or pump almost cracked, etc. But isolate the sound first, before taking more action. And on your way to Malibu buy some Maple Leafs back when they were $125....

 

Thanks for your help.

I never knew one little item could make so many noises while on its way out!

I'll keep you posted.

Paul.

 

might not be on its way out, just blowing air out of the housing instead if into the motor... having a rotted filter piece on there too helps more sound escape, but even a brand new one with a great bearing will be loud as all hell if its open the same way a hairdrier still makes a racket if you block the outlet side.

dunno if rtv would work, theres a good deal of pressure in that thing... worth a try though i guess!

 

See this link, has interior photos and one forum member replaced foam and silenced unit

https://landroverforums.com/forum/di...p-noise-23245/

 

My SAI pump make a lot of noise when the truck is first started.
Kinda cool actually.
I don't worry about it.

The plastic pipe from my SAI pump broke when I was replacing the Cylinder heads.
Need to fix that..

Just get to know what is normal for your Discovery II and you'll be fine.