: 2005 Engine Power Reduction Problem

08-27-08, 09:14 PM
I have a 2005 Cadillac STS and when I drive it for a little while sometimes the car will power down. It only seems to do it when I am in traffic or at a complete stop. The car will start right back up after it powers down. I was wondering if anyone has had a similar problem or if anyone knows what could be causing this.

08-28-08, 10:36 AM
By 'power down' do you mean it shuts off? If RPM's get to low the computer might cause the engine to shut down, what grade of gas are you using? Any 'check engine' warnings?

08-28-08, 05:06 PM
On the gauge it will say engine power reducing and then the car will shut off. Currently I am use regular gas. Do you think the lower octane hs to do with the problem. If so what octane would you recommend? Also, the check engine light will appear right after it happens but it goes away. I took it to the dealer said they could not duplicate the problem. The mechanic said maybe a throttle body down the road.

08-28-08, 05:17 PM
The problem is absolutely NOT related to grade of gasoline. Almost 50K miles on my 2006 V8 running regular, runs perfect. Used premium a few times and could not tell a difference, so stopped wasting my money.

08-28-08, 05:43 PM
When the Northstar detects an overheated condition, it severely reduces power output. Check your coolant level. Watch the temp gauge when you're stopped in traffic. If you suspect you have had any serious overheating in the past, change the oil now if you haven't already done so.

I speak from experience on a 1996 STS, where a busted radiator hose led to overheating, engine power reduced. After fixing the hose and filling the radiator, the car still appeared to overheat until the oil was changed. The oil had been ruined by the high heat created in limp-home mode. BTW, I couldn't believe how little power the car had in limp mode.