: Poor acceleration when hot.Low engine output in 85F +

Big Windy Ext
06-04-11, 07:52 AM
Well summer weather is back in my town and so is my summer drivability problem . I have had my EXT in for this before at the dealer and before I bring it in again I wanted to see if anyone else has had this problem . When the temps get above 85F my truck just doesn't have any ooomph,it doesn't miss stutter or display a check engine on the DIC. The coolant temp also remains normal . I have tried driving with the AC off , no luck . I also have experimented with different fuels,octanes,brands etc. I even have tried unleaded racing gas. I believe it must have a bad temp sensor somewhere,but which one? The truck seems to go into some kind of limp mode without displaying any sort of code or leaving any history of one for me or with the dealer,who thinks it is running just fine . Any ideas ?

06-04-11, 01:38 PM
Have you cleaned the throttle body in case it is sticking? Thats the first thing I think of changing in the heat.

escalade kidd
06-04-11, 05:22 PM
I have the same thing. Had it in my 2007 denali also..i learned to live with it.

Big Windy Ext
06-05-11, 08:16 AM
Throttle body cleaned,Maf sensor cleaned . Numerous bottles of injector cleaners also . What clues me in that it is an electrical snafu is if the car hasn't been driven but left in the heat all day it is a slug right from the first start up . I will probably talk to the dealer again when the temps are hot , I was hoping someone has had a similar issue/fix.

Cadillac Cust Svc
06-06-11, 10:19 AM
Big Windy Ext,

I am sorry to hear that this is happening with your vehicle. Please let me know if you do decide to take your vehicle back to the dealership. I would like it if you would contact me if you take it to the dealership if the issue is still occurring.

Thank you!

Elizabeth, Cadillac Customer Service

06-06-11, 04:54 PM
How many miles? has it always been like this or did it develop on you? Have you checked the fuel filter? I had a problem like this with vapor locking in hot temps.. What kind of temps are we talking about.. and does your temp gauge read any more than half?

Big Windy Ext
06-07-11, 07:48 AM
The temp gauge doesn't go up past half,it stays normal. It starts when outside temps hit 85F . It has been doing it since 12,000 miles and is at 52,000 . I haven't changed the fuel filter,not a bad idea but it runs normal any other time . I towed my trailer back from Wisconsin in April without a hiccup , 4-place enclosed snowmobile trailer. Something like a temp sensor has to be overly sensitive making it limp this bad,it doesn't matter if the ac is on or not .

06-07-11, 10:23 AM
If it were a temp sensor I would suspect it would function poorly more often. 85f is not hot at all I am in Tulsa and and seeing temps as high as 100 right now. Fuel sounds like a possible culprit because it can be affected by temps heating up and vaporizing but 85 doesn't sound high enough and I would be suffering from it too. Do you have an aftermarket air intake? Mine came lose one time and gave me similar results.

06-07-11, 11:29 AM
Preach 85 in Chicago is a beast! Humid as hell...

Big Windy Ext
06-07-11, 03:10 PM
Mid to upper 90's 30-100% Humidity now. My diesel's clutch fan is coming on now too. I hate touch screen phones in this weather. I hate hot weather period.