[nkkilla]

Today it was like 92 degrees F here, and my car had been parked for about 5 hours under the hot sun on a gravel. I take off from the parking lot and I noticed rear differential temperature light coming on in 3rd gear. I immediately pull over and wait several minutes and take off again, and the light comes back on every time I go over ~2500 rpm in each gear. I tried to keep rpm under 2000 on my way home and now the light comes on past 3000 rpm (temperature is now like 82 degrees F) As soon as I lift my foot off the gas, the light goes off. Could this be simply due to having not enough fluid in the rear diff.? I have about 14000 miles on my car.. Will I be okay by just changing the fluid or will I need to take my car to a dealer..

[91TB78]

It certainly could be low diff fluid. Since you're at 14K, why don't you change it? The manual states 15K intervals for extreme use. If you drive the car really aggressively and/or any hard launches, autox, or track days I would recommend it.

[wdb]

This is an unusual problem, in fact I have never heard of it before. 14K miles = still under warranty. Get thee to a dealer, pronto.

[rbento11]

What was you DCCD set to?

[nkkilla]

my DCCD was in auto.. and I want to change the fluid myself rather than going to the dealer to change it cause I'm really busy with school and the only day I can head out to a dealership is next week saturday..

[Rev]

Originally Posted by nkkilla

my DCCD was in auto.. and I want to change the fluid myself rather than going to the dealer to change it cause I'm really busy with school and the only day I can head out to a dealership is next week saturday..

Very easy to change it

You need a 1/2" large breaker bar to remove the drain plug. Some threadlock sealant would also be good.

And a pump thing to fill in with the new fluid.

[nkkilla]

and what's the best brand to use? Even my dealership doesn't use subaru oem fluid.. they said they use aftermarket 80W90.. are mobil 1's okay to use on sti's?

[Digitalfiend]

Now this is going to sound silly, but you are positive it was the rear diff light and not the IC sprayer light? People have mistaken one for the other before (even though one is red and the other yellow.)

I guess it is possible if the car was hot enough when parked that the heat from the exhaust and pavement/gravel just heated the rear diff and its oil to the point where you started to see problems. It still sounds strange, so I would go have it checked.

[polyol]

This is the FIRST thread where the rear dif light has come on...that I have read. Take it to the dealer...either you have a defective rear dif or you have a haywire idiot light thingy...

[staticx313]

Originally Posted by Digitalfiend

Now this is going to sound silly, but you are positive it was the rear diff light and not the IC sprayer light? People have mistaken one for the other before (even though one is red and the other yellow.)

I guess it is possible if the car was hot enough when parked that the heat from the exhaust and pavement/gravel just heated the rear diff and its oil to the point where you started to see problems. It still sounds strange, so I would go have it checked.

This is definitely a good point. Make sure it is indeed the diff light and not the I/C spray light. I would make sure the I/C spray is completely full as well to eliminate that possibility. Best of luck to ya.

Robert~

[nkkilla]

Originally Posted by Digitalfiend

Now this is going to sound silly, but you are positive it was the rear diff light and not the IC sprayer light? People have mistaken one for the other before (even though one is red and the other yellow.)

I guess it is possible if the car was hot enough when parked that the heat from the exhaust and pavement/gravel just heated the rear diff and its oil to the point where you started to see problems. It still sounds strange, so I would go have it checked.

I knew someone was gonna ask me this.. no it wasn't the ic sprayer light. I'm sure because I saw the rear diff. light going off not once, nor twice, but like 10+ times.. and I don't think the exhaust heat could've affected because the I only drove the car for like 10 min before I parked it and I left it parked for 5+ hours.. Another reason why I wouldn't want to head right away to dealership is because I have some mods like intake, exhaust, and cobb AP.. and subaru might not honor the drivetrain warranty because of those.. or am I wrong? But regardless, I guess I'll have to go to a dealership anyway..

[supersubes]

it isn't the fluid temp there is no way ambient temps did that. If you can hammer the car on the track for 45 mins and not get the light, then there is no way you did it in a parking lot. I would find a way to take it to the dealer. Just make an appointment and they will do it while you wait. I think it is electrical (sending unit) but if you have a diff issue they will fix it. I don't think they will give you an issue for the mods...if you are concerned about the AP, un-marry it and then take it in. Even if you grenaded the diff they would have a hard time pointing to an intake and exhaust.

[WE_R_ND]

I'd play it safe and take the mods off. Correct they didn't do it, but there are dealerships that will void the warranty for anything.

[nkkilla]

well I drove my car today and the rear diff temp light no longer comes up.. Am I safe here to just keep driving my car or should I still take it to a dealer? I mean, even if I take it there, will they do anything about it since they can't replicate the problem?

[supersubes]

at least get under the car and stick your finger in the fill hole. Check the level (should be up to the bottom of the hole). You'll know by the look of it wether it is cooked or not. and by the way gear oil always smells real bad. The idea being there is 1) oil there and 2) it isn't full of metal shavings which would be a sign of a deteriorating gears or LSD.