Flickering lights and engine bogging

01 Suburban LS · July 19, 2004

This weekend my brother had some problems with my 2001 Suburban while in Las Vegas and on the drive back home to San Jose. It has a little over 50,000 miles on it, I purchased it last September with a little over 44,000 miles. Other than what little I have done to it, I do not know of any other maintenence.

Problem #1

While driving around, he would notice that the dash/cluster lights would dim and flicker.

Problem #2

The fuel pump would get louder and louder the quiet down.

Problem #3

Engine was bogging and SES light illuminated. Hooked up the laptop running OBD II software and got a P0131 and P0151. Fuel system running in open loop mode and some sort of problem with the 2nd bank O2 sensors.

Problem #4

The clutch on the cooling fan would come on at odd times. Even when he got closer to home in the cooler temperatures.

My brother took a freeze frame snap shot of what the engine was doing and it said:

Outside temp: 116

Speed: 90 MPH

RPM: 3900 RPM

Coolant Temp: 202

Intake Air Temp: 108

Any suggestions????

seadoons · July 19, 2004

90MPH? That's fast! Maybe he was pushing it too hard...

Check the battery first. My brother's battery started going bad and it did all kinds of weird s**t..

01 Suburban LS · July 19, 2004

90MPH? That's fast! Maybe he was pushing it too hard...

Check the battery first. My brother's battery started going bad and it did all kinds of weird s**t..

I replaced the battery shortly after I bought the Suburban. I now have an Optima Red Top

Shaners · July 19, 2004

Possible alternator/voltage regulator problem?

Did he happen to notice any fluctuation in the Volt gage?

az'03Silverado · July 19, 2004

Check all of the ground straps. I know, it sounds stupid but they have a lot to do with the proper function of the electrical system. There should be one on the hood and one or more down on the engine/tranny. If they're frayed or broken or loose, they won't allow the electrical system to ground properly and may cause some of the problems. That's all I could think of.

01 Suburban LS · July 20, 2004

Possible alternator/voltage regulator problem?

Did he happen to notice any fluctuation in the Volt gage?

We were thinking the same thing. He happened to look at the gauge and it didnt move. The alternator may still be putting out the correct voltage, but not the correct amperage.

Check all of the ground straps. I know, it sounds stupid but they have a lot to do with the proper function of the electrical system. There should be one on the hood and one or more down on the engine/tranny. If they're frayed or broken or loose, they won't allow the electrical system to ground properly and may cause some of the problems. That's all I could think of.

I'll be sure to check those. I decided to check to see how the plugs looked to see if it was running rich. Bogging down is a sign of that. I found the plugs looked OK. They were/are Denso Iridium with a massive gap. I also broke a wire trying to get it out. Good thing this is not my daily driver.