Question Asked: Unknown Reduction in Fuel Mileage
December 19, 2009, 08:39 AM
About 3 weeks ago I noticed that the fuel mileage in the Suburban went from a very good 16-18mpg to a dismal 13-15mpg. Along with this, I noticed that at a dead stop (stop light) the engine rpm jumps up a few rpm for split second and settles back to normal. It does not occur on every revolution of the engine. These issues started to occur with a couple of weeks after changing the spark plug, wires, and rotor cap...and after re-gapping the spark plugs.
The fuel system from the pump in the tank to the TBI was replaced less than 18 months ago.
A bit perplexed by the two likely related issues.
Thank you for your help.
Question Asked: Brake System
March 13, 2009, 06:10 PM
During wet/snow condtions the ABS does not operation properly. When breaking under these conditions the brakes do not engage properly, there is a shutter feeling in the steering wheel and brake pedal and very odd noise from the front end. The truck does not slow/stop like it should. My guess is that the ABS module is defective but I'm not sure.
Thank you for your assistance.
Question Asked: Coolant Circulation
March 13, 2009, 03:56 AM
After running the truck for a distance of up to 15-20 miles and then turning the ignition off, coolant leaks from some location on/around the radiator, possibly the heater hoses. Coolant apparentely is not circulating through the engine since when checking the upper hose, it is found to be very hot, the lower hose is warm, and when squeezing either hose, there is not movement of air or fluid into the overflow/fill tank. There is warm air that comes out of the heater when engaged but it is not hot.
Three guesses are - 1) thermostat though the truck has not overheated and internal gage reading is "normal"; 2) water pump though not leads or squealling sounds coming from pump: or 3) a clogged radiator.