Surging idle when cold.

[pito11213]

Okay, First a hello from a first time poster. I have been around for a sec enjoying the many accomplishments you guys have made.

I have a 2002 LT Suburban. Now I have noticed as of late that when it is pretty cold outside and I first start the truck, that I get an up down aka surging idle. This goes away once the engine has heated up all the way. On occasion I get a CEL, but it will go away on its own. I have searched this site and I have my suspicions, but I want as many suggestions as possible before I continue.

 

[jey_]

Most auto parts store will pull that CEL code for free - that will help you narrow it down.

 

[Sepiroth]

Yes exactly have the code checked. You typed that it has come on so chances are there is a code in the PCM memory. I know Autozone, Advance, pep Boys will do this for free.

 

[ronerider]

Hello, I have the same issue on my 03 Tahoe. Surging idle in cold temp, ok when motor reaches operating temp. Error codes indicate Mass Air or gas tank pressure sensor. What was the root cause in your surging issue, interested as symptoms are identical. I heard that the intake manifold gasket can cause same symptoms. Thanks.

 

[Sepiroth]

Hello, I have the same issue on my 03 Tahoe. Surging idle in cold temp, ok when motor reaches operating temp. Error codes indicate Mass Air or gas tank pressure sensor. What was the root cause in your surging issue, interested as symptoms are identical. I heard that the intake manifold gasket can cause same symptoms. Thanks.

What I would do in your case is get a can or carb cleaner and spray around the intake and intake ports to the head. What you will be listening for in a change in idle.

 

[ronerider]

Thanks a lot Sepiroth, will check and report back.

 

[ronerider]

Forgot to report! It turned out to be the intake manifold gasket. Replaced gasket and running fine.

 

[chris48559]

Same thing happened to mine last month! Took me forever to figure out what it was :mad3: