20 Most Recent 1993 GMC Sierra C3500 Questions & Answers

low on oil or burned band or selonoid

IF you have a viscous fan hub driving the fan then replace it with a new unit. IF electric fan/s then check fuses and fans for correct operation. Have a coolant system check done and have a flow test done on the radiator. Ensure that the radiator fins are not blocked up with mud/snow or paper/plastic. Have a compression test done to check for head gasket or cracked head.

Here's what my problem was in my '93 GMC when this happened.. A speed sensor was faulty.. The dealership hooked me to their computer and they had the answer right away.. They changed the sensor (not a big deal) and it's worked perfectly since.

All that work should have fixed the problem, but unfortunately white smoke means coolant, need look for a leak in a head gasket.

sounds like the alternator

check the linkage adjustment and also a bad motor mount

no, the ignition cylinder may have to be replaced to start.

you have injectors that will not seat when closed. Most likely you will need to replace them change the fuel filter as well every year to prevent them to clog up

Hi, the EGR valve is sitting on the intake manifold as shown below. Yes, this valve can be the cause of had start/rough idle if it is stuck open. Remove the valve to see if you can blow thru it. If it's stuck open, you may be able to repair it by cleaning with carb cleaner. If you cannot get it to close properly, replace it. If the valve is closing properly, pull off the vacuum hose, start the engine, and make sure there is no vacuum on the hose at idle. If there is, the vacuum solenoid may have failed open. The solenoid is shown in the second picture below. You should not be able to blow thru this one either, except when it is turned on by the PCM. Please let me know if you have more questions, and thanks for using FixYa.

sounds like the timing

You cannot fix this. Please take your Sierra to your mechanic for internal repair and adjustment.

I got this from Haynes Diesel Engine Repair Manual. I bought it for my 6.2.
1. Remove the fuel filler cap and air cleaner assembly.
2. On filters without an air bleed screw, place a rag under the filter to soak up fuel and detach the lower clip FIRST to release pressure and then the top clip. They pop off with a screwdriver.
3. On filters with an air bleed screw (top passenger side) drain fuel from the filter by opening the screw first and the engine water drain valve (engine front near thermostat) if it has one. Detach the clips and remove filter.
4.Make sure the seating surface is clean and place new filter in position. On non-air bleed filters put the upper clip on FIRST. On air bleed filters secure both clips, then close the valve and attach a piece of hose to the bleed port into a pail.
5. Air must be purged BEFORE start up, so disconnect the pink wire from the top of the injector pump and crank the engine in 10 second cycles with a 30 second wait time until clear bubble-free fuel comes out the lower fitting or air bleed. Connect the lower clip on the non-air bleed , close the bleed hose and reconnect the pink wire.
6. Start the engine and let it idle for several minutes to purge any remaining air and check for leaks.
Hope this helps.

FUEL FILTER MOUNTED ON A BRACKET TO THE REAR OF THE INTAKE MANIFOLD.TO REMOVE FUEL FILTER.TURN OFF IGNITION.RELEASE ANY PRESSURE OR VACUUM IN THE TANK.DRAIN THE FUEL FROM THE FUEL FILTER BY OPENING BOTH THE AIR BLEED AND THE WATER DRAIN VALVE ALLOWING THE FUEL TO DRAIN INTO A SUITABLE CONTAIMER.UNSTRAP BOTH BAIL WIRES WITH A SUITABLE TOOL AND REMOVE THE FILTER.INSTALLING THE NEW FILTER ENSURE THAT BOTH FILTER MOUNTING PLATE FITTINGS ARE CLEAR OF DIRT.SNAP THE FILTER INTO PLACE WITH THE BAIL WIRES.CLOSE THE WATER DRAIN VALVE AND OPEN THE AIR BLEED VALVE.CONNECT A 1/8 INCH I.D HOSE TO THE AIR BLEED PORT AND PLACE THE OTHER END INTO A SUITABLE CONTAINER.DISCONNECT THE FUEL INJECTION PUMP SHUTDOWN SOLENOID WIRE.CRANK THE ENGINE FOR 10 - 15 SECONDS THEN WAIT 1 MINUTE FOR THE STARTER MOTOR TO COOL.REPEAT UNTIL CLEAR FUEL IS OBSERVED COMING FROM THE AIR BLEED.IF ENGINE IS TO BE CRANKED OR STARTED WITH THE AIR CLEANER REMOVED CARE MUST BE TAKEN TO PREVENT DIRT FROM BEING PULLED INTO THE AIR INLET MANIFOLD WHICH COULD RESULT IN ENGINE DAMAGE.CLOSE THE AIR BLEED VALVE RECONNECT THE INJECTION PUMP SOLENOID WIRE AND REPLACE THE FUEL TANK CAP.START THE ENGINE ALLOW IT TO IDLE FOR 5 MINUTES AND CHECK THE FUEL FILTER FOR LEAKS.

The idle is either set to high (sometimes rattles loose) or if it is a thumping fromthe cab your drive shaft's U joint may be going out. Also check your Brake Fluid and bleed the system - you may have inevertantly gotten an air buble in it and that will cause the ressureon the calioers to fluctuate - causing the vehicle to "Jump".

this is a classic example of a throttle position sensor gone bad. GMC products from 1988 on are notorious for this.

egr valve may be causing problems. also check the throttle position sensor

wrong ignition timing, low fuel pressure or burn valve.
check your fuel pressure, ignition timing and check engine compression