The ignition switch on my '98 is sticky. What I mean is that about 1/2 the time, after inserting the ignition key and turning the key to "start" position, the switch does not return to "run" after I release the key. Instead, it returns part way, sitting between "run" and "start". This disengages the starter and allows the engine to run, but electricity to instrument panel remains shutoff (as it is in "start" position). I have to manually turn the key rest of the way to "run" position to gain electric power to the IP. The key inserts into the cylinder easily, removes easily, and does not seem to need excessive force to turn the cylinder.

I've searched the forum, it's unclear whether I can lube the lock cylinder (and if so, with what), or whether the lock cylinder itself needs to be replaced.

Suggestions?

 

It sounds like the ignition switch to me. If lubing it like 8vette7 says doesn't work then I would go to the DIY thread on top of c5 tech and go to post 118 and theres instructions on how to take apart the switch and see what's going on. You might need to get a new switch but it's worth a shot.

 

100%. I used electrical contact cleaner on my truck for a similar issue and it worked very well. If you must use a lubricant I'd go with a SMALL amount of either graphite or silicone. Try just the cleaner first and see where you are.

 

By any chance do you have a heavy set of keys? Heavy keyrings play havoc on ignition switches over time and it's one of the top causes for ingition switch damage.

 

The guy who installed the stereo in my car had the small bezel around the ignition ****-eyed causing some binding, acting just like yours. Just a thought...

 

You nailed it.

Weekend before last I replaced the inside air temperature sensor for the HVAC system because a check of diagnostics codes was showing DTC B0338 for "inside air temperature sensor open" as a current code; it would pop right back up as soon as I would reset it.

To replace the IAT, you have to remove the center console, radio/HVAC trim, and driver's side bolster panel. In taking this all apart I discovered that the previous owner's "mechanic" (I'm being kind) had had his way with the car, cracking one of the mounting flanges on the bolster, replacing one of the proper screws for the bolster with a wrong-size hex head self-tapping screw, breaking some of the mounting tabs on the ignition switch bezel, and wedging an edge of the bezel under the radio/HVAC trim panel to hold in place... cockeyed, while leaving the inside air temperature sensor unplugged.

Time, bumps in the road and everyday vibration eventually caused the ignition switch bezel to work into a position where it was causing the ignition lock cylinder to bind a bit.

I had bought a new IAT sensor (about $30), so I installed it even though the old one is probably OK, and reassambled all the trim using correct hardware with the ignition switch bezel in the correct position. The bezel is loose because of the broken mounting tabs, but the ignition lock cylinder no longer binds. Better yet, I scored a new ignition switch bezel from GMPartsHouse at Carlisle this weekend, so I'll replace the broken one someday soon.

Curiosity question though: there's some sort of rubber cord (or rubber-insulated wire?) wound around the bezel two turns. with the midpoint fastened to the bezel's edge with a small plastic clip. The ends of the cord are attached somewhere deeper in the dash, and I didn't feel like going prospecting to see where.

What's the purpose of this cord?

BTW, the frame of the bolster is ABS plastic, so I applied a little PVC solvent (the very same stuff you use to glue PVC plumbing) to the cracked pieces and clamped them with a spring clamp overnight... good as new!

And the A/C works great now, too.

 

That "cord" you speak of is the wire that connects the two small contacts in the lock cylinder (to "read" the key pellet) with the BCM. It's looped/coiled to allow it to be moved when turning the key through it's various positions and not put a strain on it. It's made of very fine wire (24ga or maybe 26ga?) to be flexible. Be careful with it.

 

Got it, thanks!