: Differential fluid overheating message on 2011 CTS V coupe at VIR



hman123
05-31-11, 12:25 PM
Ran the Grand Course at VIR this last weekend. In advanced group so running car hard, but within 20 minutes into first session message came on that differential fluil overheating and need reduce speed. Ran second session and same message came on. Took to dealer and they drained fluid which was burned but not damage. Had replace with Royal Purple but still max viscosity 90 as recommended. Ran next day was ok two sessions then came on again 3rd. There is a differential cooler they said could add but felt if ford focus could run this course the V should expecially since cooler is an option not even listed anywhere. Anyone with same issue. Concern that running 140 viscosity will void warranty which is what dealer led me to believe.

MReiland
05-31-11, 12:46 PM
Sustained High Speed driving usually requires the diff cooler per previous threads from Ed Piatek. You can get the dealer installed unit and retain your factory warranty on the rear diff or go aftermarket. I believe in one of the previous threads there was a comment such that many other similar performance vehicles don't have the temp switch on the diff so you wouldn't know if they are cooking the fluid or not, also the V has quite a bit of cast iron in the housing instead of aluminum which probably doesn't let it shed heat as fast but it holds up to the power of the V. I think I remember seeing the export V's are fitted with the cooler standard as they will likely see much more sustained high speed driving.

thebigjimsho
05-31-11, 01:38 PM
I just wish the stock cooler didn't cost 5% of the V's purchase price...

baabootoo
05-31-11, 02:21 PM
If you want more info, there's got to be 80+ posts on this already. A thicker viscosity will cause MORE heat, since it will take more energy/heat to move it. There was also a thread on a very economical way of making a cooler too. MAYBE $300 invested? This is a hit or miss thing, like all other issues. I still believe that one differential doesn't get all that hotter than others, so it's a sensor issue. Get a $20 laser heat gun and check it when it goes off.

Dr. Design
05-31-11, 03:49 PM
Hello,
Yes this is a known problem for the V cars when pushed at the track. We do offer a rear diff cooler for the coupe. Give us a call as they are all built to order.

All of the road race cars we build have the diff coolers installed and no rear diff temp lights!

Thank you,

Dr. Design
D3 Cadillac


Ran the Grand Course at VIR this last weekend. In advanced group so running car hard, but within 20 minutes into first session message came on that differential fluil overheating and need reduce speed. Ran second session and same message came on. Took to dealer and they drained fluid which was burned but not damage. Had replace with Royal Purple but still max viscosity 90 as recommended. Ran next day was ok two sessions then came on again 3rd. There is a differential cooler they said could add but felt if ford focus could run this course the V should expecially since cooler is an option not even listed anywhere. Anyone with same issue. Concern that running 140 viscosity will void warranty which is what dealer led me to believe.

JimmyH
05-31-11, 03:55 PM
I am guessing you meant 2011, not 2001.

Domsz06
05-31-11, 05:27 PM
like others have said this is pretty common for the people that road track their cars. It really sucks that GM won't allow us to get this on our cars, or they want to charge us an ARM AND A LEG for it. D3's looks pretty solid, but also costs some dough. If your already tracking it your voiding your warranty anyway so might as well get an aftermarket if it's cheaper. I doubt you will do any more harm.

I know technically by tracking your not voiding your warranty, but stranger things have happened if GM finds out.....

EricVonHa
06-01-11, 01:34 AM
To the original poster: Are you using slicks or the PS2's ?

Ambient temp makes a huge (starting point) difference for the diff. You guys certainly had a hot one!

Umrswimr
06-01-11, 09:37 AM
Argh... Stupid forum...

Umrswimr
06-01-11, 09:37 AM
I just wish the stock cooler didn't cost 5% of the V's purchase price...

This.

Domsz06
06-01-11, 09:40 AM
Argh... Stupid forum...

i feel the same way at times lol :)

TRACKTRIX
06-02-11, 03:50 PM
As the second driver of this car I can tell you the only modifications done are Carbotech Race pads all around and ATE fluid. It will probably have some ducts on it next time out. Ambiant temps for the weekend were into the 90's. The mornings were comfortable and both days the initial time the warning came on was during a session before lunch.

It really is a shame that GM built such a wonderful car but didn't take the extra steps needed to make the car truly reliable. The owner/ OP has had 2 C6 Corvettes w/ Z51 package before the V. We have both driven the Vettes much harder than the V (this was only the second event in the car). I know there is more speed and capability in the car that we haven't even tapped. Yet we already have diff problems. Now the Vettes may not have had a temp sensor to tell us that the diff or trans was over heating but we never had any known issues with either car.

I guess sometimes ignorance is bliss.

The owner is still talking with the dealer to see how much they are going to charge for the GM cooler kit installed. They said they would do it at their cost, we'll see.

Depending on what the dealer says, I may make up my own kit.

C.R.

bmw m5
10-26-11, 11:27 AM
I have 2011 cts-v coupe my diff has overheat 5 time dealer has change fluid couple of times the lastest they installed oil cooler for the diff but still happens it actually overheated quicker cruising at 125 -140 for 20 minutes the idiot light came on and said reduce speed .the oil got so hotit overflowed.

Nutz
10-26-11, 02:24 PM
I'd like to see someone experiment with an air scoop of some kind. The cast iron can probably be cooled enough to assist in this problem.

garfin
10-27-11, 07:45 AM
It really is a shame that GM built such a wonderful car but didn't take the extra steps needed to make the car truly reliable. The owner/ OP has had 2 C6 Corvettes w/ Z51 package before the V. We have both driven the Vettes much harder than the V (this was only the second event in the car). I know there is more speed and capability in the car that we haven't even tapped. Yet we already have diff problems. Now the Vettes may not have had a temp sensor to tell us that the diff or trans was over heating but we never had any known issues with either car.


C.R.

ZL1 Camaro will come from the factory with a diff cooler as standard equipment... would be nice if GM could find an economical way of including it on the V - even as an option.
http://media.gm.com/content/media/us/en/gm/news.detail.html/content/Pages/news/us/en/2011/Sep/0909_camaro_zl1

Best regards,

Elie

Prof
10-27-11, 09:33 AM
After reading the above the question that comes to my mind is...does the pcm start to reduce performance when the differential warning light comes on??? Could it be that the heat point at which the sensor sends the warning signal just a cautionary point or is it a point at which the system is degraded to protect the rear end? Often warning messages are very conservative, and the point at which damage might occur is well beyond the point at which the warning is issued.

Anyone know?

Prof
10-27-11, 10:33 AM
Wonder if we could get Ed Piatek to opine on this issue...

Ed are you still around???

OldRoadDawg
10-27-11, 10:40 AM
Wonder if we could get Ed Piatek to opine on this issue...

Ed are you still around???
Looks like he hasn't checked in for awhile...

Last Activity: 06-06-11 09:30 PM

thebigjimsho
10-28-11, 09:23 PM
I'd like to see someone experiment with an air scoop of some kind. The cast iron can probably be cooled enough to assist in this problem.Yeah, I don't think it needs that much help to stay under critical temps. But I think Cadillac worked a lot on underbody aerodynamics and don't know if I'd play with scoops. I would like something that doesn't cost crazy dough...

Junior1
10-29-11, 12:07 AM
Just inquired about the new batch of V's at Monticello.
All the Sedans come with the factory installed external coolers mounted under the trunk and apparently the Coupes have a pump with a big heatsink for a cooler that runs the length of the car.
But again all factory installed. I'll crawl under a few and get some pics the next time I'm up there.

thebigjimsho
10-29-11, 01:42 AM
Bring your wrenches, too...

Wireboltman
10-29-11, 01:38 PM
I had the same thing happen when I took my car to the Gingerman Race Track in South Haven, MI. over Labor Day this year.
Of course, it was 94F with around 100% humidity, also.
Sessions were about 15-20 minutes.
I ran 2 sessions no problem. The 3rd session right before lunch, it overheated.
Cooled down for about 1.25 hrs during lunch and I ran two more sessions without overheating.

muohio
10-29-11, 11:34 PM
As the second driver of this car I can tell you the only modifications done are Carbotech Race pads all around and ATE fluid. It will probably have some ducts on it next time out. Ambiant temps for the weekend were into the 90's. The mornings were comfortable and both days the initial time the warning came on was during a session before lunch.

It really is a shame that GM built such a wonderful car but didn't take the extra steps needed to make the car truly reliable. The owner/ OP has had 2 C6 Corvettes w/ Z51 package before the V. We have both driven the Vettes much harder than the V (this was only the second event in the car). I know there is more speed and capability in the car that we haven't even tapped. Yet we already have diff problems. Now the Vettes may not have had a temp sensor to tell us that the diff or trans was over heating but we never had any known issues with either car.

I guess sometimes ignorance is bliss.

The owner is still talking with the dealer to see how much they are going to charge for the GM cooler kit installed. They said they would do it at their cost, we'll see.

Depending on what the dealer says, I may make up my own kit.

C.R.

Doesn't the Z51 package include an oil, trans and diff cooler? I know the Grand Sport package which replaced it has one.