[Richard]

I went on a fairly long trip this past weekend. It was extremely hot outside (97 degrees), so I had the air conditioning on. I got stuck in a bad traffic jam. Once I starting moving, I noticed the car was hesitating and surging a bit. Being stuck in traffic in 97 degrees with the a/c blasting must have really made the engine run really hot. I heard the cooling fans running continuously.

Once the traffic cleared and I got up to normal speed, the problem went away and everything seemed fine.

But for a little while, I was kind of nervous that overheat protection mode was going to activate. The temperature gauge never left the so called normal range though.

I know that 4 cylinders run hotter than 6 and 8 cylinders. Would this be a characteristic of a 4 cylinder in extremely hot weather.

FYI - The engine coolant is at the normal level and the cooling fans are working fine. The car is 5 months old.

 

[Silver LTZ]

Remember that the temp gauge is really just a glorified idiot light. It won't vary to much unless it gets very hot. I assume your coolant is okay?

 

[joeygtp]

I think you are experiencing the surging issue being discussed in this thread: http://www.chevymalibuforum.com/forums/showthread.php?t=4843

Same symptoms I have. Only when it's hot outside.

 

[RaineMan]

Sounds like relatively normal operation to me. Both the primary and secondary fans always run when the A/C is on. We used that trick to cool the engines down on the Cobalts between drag or autocross runs.

One thing I dislike with this car is that it has a traditional temperature gauge that really doesn't move once it is up to temp. I always used the digital temp readout on my Cobalt and could see it fluctuate between 180 and 210 as conditions changed.

 

[onecrazyfoo4u]

I live in the desert, 110 for 2 months every summer. My fans are screaming full blast constantly (since the A/C is on max a lot of the time). And I'm stuck in traffic often, sitting still. It's pretty normal...and of course the 'fake' temperature gauge never moves past normal.

 

[Richard]

Remember that the temp gauge is really just a glorified idiot light. It won't vary to much unless it gets very hot. I assume your coolant is okay?

You took the exact words out of my mouth. There's no doubt that the engine was running hot, but the temperature gauge stayed in the same range that it always does. Didn't even vary at all. As we know, this is not how a temperature gauge should work, but my last 3 cars had this same type of "idiot light" style temperature gauge.

The coolant is fine. It was just a really hot day and I hit a bad traffic jam, so I was at a stand still with the air conditioning on high. I truly believe it's just a characteristic of a 4 cylinder. They run hotter than a 6 would in extreme heat. Once the traffic cleared and I got up to normal speed, the engine was fine.

 

[Richard]

I think you are experiencing the surging issue being discussed in this thread: http://www.chevymalibuforum.com/forums/showthread.php?t=4843

Same symptoms I have. Only when it's hot outside.

Actually, it was more of a hesitation than surging. When I hit the gas, you can feel the car holding back, then it would speed up and hold back again. I truly feel it was heat related. It was just shy of 100 degrees outside and I was stuck in traffic for about 20 minutes with the air conditioning on high. This was the only time this happened to me. Once the traffic cleared and I got up to normal speed, everything was okay.

 

[Richard]

Sounds like relatively normal operation to me. Both the primary and secondary fans always run when the A/C is on. We used that trick to cool the engines down on the Cobalts between drag or autocross runs.

One thing I dislike with this car is that it has a traditional temperature gauge that really doesn't move once it is up to temp. I always used the digital temp readout on my Cobalt and could see it fluctuate between 180 and 210 as conditions changed.

I definitely agree. This was normal given the conditions I was driving in. And this is the first 4 cylinder I've owned, so I'm still getting used to some of the characteristics of a 4 cylinder. 4 cylinders run hotter than 6 & 8 cylinders to begin with. Add 100 degrees heat and it really runs hot.

I had 3 Caddy's that didn't have a temperature gauge, but you can access the digital temperature reading right through the DIC. I prefer that much more. This way, you can anticipate a problem before it occurs. In extreme heat, I saw coolant temperatures as high as 230 degrees. With the temperature gauge in the Malibu, it won't go to hot until it's too late and you're overheating.

 

[joeygtp]

Actually, it was more of a hesitation than surging. When I hit the gas, you can feel the car holding back, then it would speed up and hold back again. I truly feel it was heat related. It was just shy of 100 degrees outside and I was stuck in traffic for about 20 minutes with the air conditioning on high. This was the only time this happened to me. Once the traffic cleared and I got up to normal speed, everything was okay.

Sorry, I should have directed you to one of my posts on that thread, #19, where I said that I had experienced the same hesitation while driving in Washington D.C. on a very hot day. If I started off at anything more than about 1/3 throttle, the engine would hesitate for a second, then go. It seemed to coincide with the surging isue, although at that time using the manual shifter didn't do anything, as it was occurring in 1st gear. At that point, I was thinking it may point to something broader than just the transmission in extreme heat, maybe the PCM dialing back power to protect the drivetrain. I have noticed the engine feeling spongy in traffic on hot days, just that day was the worst.