A few weeks ago I started getting a very loud whirring noise coming from a black unit bolted to the firewall on the upper passenger corner of my 04- not sure what the part is. The noise goes away after maybe a minute. I've always noticed a faint fan-like noise from the same unit? during startups- warm ups and assumed it was smog related equipment? As I think about it, this fan or whatever it is dosent always kick in during a start. It usually only comes on after a long time passes between starts, like in the morning or after being parked for a few hours or more.
Now, yesterday my battery failed to start the car. It tried to turn over for a second, then the loud clicking noise of a dead battery. I went on to jump her maybe 5 different times that day as i was out running errands and the jumps seemed to work, with no other apparent problems once running. Unfortunately tho driving up to 5 miles and plenty of idling wouldn't recharge the battery as would normally happen with a good battery. Then this morn I went to start her expecting a completly dead battery but instead it started- tho hesitently as if there was little charge left. Its been like that all day today, and dosent seem to be getting better but at least an unexpected improvement over yesterday.
Battery and connections all seem fine. I believe the battery is the og Interstate battery.
Are the problems possibly related? My guess is whatever is making the loud noise might be over taxing the battery.

 

SEARCH, Please --- SAI.

 

Ok- SAI or secondary air injection, a smog part. Thanks. But I can't even search the forums as it wont allow just SAI as a search term
So I went with "secondary" as a search term and yeilded some good results. Could be the filter, could be the mounts, or could be the unit is bad and needs replacing. If so, is that normal at 80k miles?
Also, no info that related a failing SAI with a dead battery.

 

its possible that the SAI pump or if there is a relay maybe shorted causing a drain on the battery.

 

thanks, thats the insight I'm looking for, even if you are guessing. Strange tho that I'm not throwing any codes?
Where does one find the SAI relay?

 

5 miles is in no way long enough to charge a dead battery, it takes min 30 min of the engine running to charge a battery, that is assuming no extra load on the charging system, like the a/c on, stereo, lights, etc.
Put it on the battery charger, let it charge overnight and then have the battery and alternator tested.
Check the battery for the date label being stamped, that will tell you how old it is, if it is the original battery it is toast.
DLG-34 from AutoZone.

 

If I was on my computer, I would tell you, but im doing this off my phone

 

Go to your local parts store and have your charging system checked for free, voltage should be between 13.6 and 14.4.

 

Voltage checked in at 14.12 so the alternator is fine. Battery tested bad, replaced with the recommended Interstate battery- same one as the OEM 700 Amp 72 month original. Mechanic said batteries usually go bad right around their warranty expiration, and since mine was OG and the trucks an '04 that put me at about 7 years, a year over warranty, so it made sense. He also thought the bad battery was contributing to the crazy sound coming from the SAI, being that it sucks alot of juice and activates right at cold start before the alternator has a chance to fully charge the system and so the SAI relies on mostly battery juice and if that's low it doesn't get enough amperage to operate correctly- hence the high pitched whine.
Sounded like a decent theory. So I replaced the battery yesterday and walla- after many test starts the rough start is officially gone, so the jumper cables are no longer needed. But this morning at cold start the SAI was once again loud- but not as loud as before.
Did I "fry" the SAI with the bad battery? If so, I've seen other posters just deal with the loud sound and not bother with it. No codes thrown, so might I try the same? Can the SAI last like this for months or years? I don't want to be left stranded.

 

There are bearings in the SAI pump that can go bad. But you can also see if the filter is just clogged causing the pump to strain --> https://landroverforums.com/forum/di...p-noise-23245/

Mine sounds like a shop-vac (which is normal I assume) is that what you're getting? Or does it sound WAY worse?