Hey guys n gals,
1982 k20 suburban 6.2 diesel automatic trans. Th400 with overdrive.
I've made this a bit of a long post because i crammed it with history and details, and questions, figured that would me get clearer answers than
Glow plugs no work, help.
So the glow plugs give me a hard time,
I changed 7 out of 8. The 8th one snapped in half coming out and the other part is still in there. Gonna have to get an easy out and get that guy out. But when driving, the glow plug light (GP) comes on. Weird, I thought it only comes on for the start and maybe the first few minutes of running to maintain a certain temperature when it's cold out.
But no, she's plenty warm enough, been running for a while and still, it comes on.
When it does come on, if I'm coasting or at a light, it's all good. If I press down on the accelerator, it's makes this infernal belt screeching racket. (Side note, I checked the belts, they're good, right, plenty of bite left). But when the GP goes out, back normal running (I have to lift off the accelerator, and back on it again otherwise the noise seems to continue).
That's really weird!
Fast forward to October 2021, driving along GP come on do their screeching noise, and light goes out, but the truck died on me. I dont know if it is related to the GP light issue, because it happened about 8 more times on my drive, GP light on and light off. I pulled over, park. Starts right up again, no fuss. So can't be the battery. (Not fuel either I was full, and it didn't sputter or hard start).
Fast forward again, I plugged it in (quebec winter are cold) and decided to give it a shake down, died on me again, started right back up. But then as I'm parking (backing into my driveway) the GP light flashes on n off like a turning blinker only faster, I hear the relay clunk clunk clunk (mounted on driver side fender, next too windshield washer bottle).
What is happening here! Then yesterday I decided to run it up again to see if it was intermittent. It cycled fine the first time, then when I tried to start, I had this weird sort of grinding noise, like maybe the starter gear turning, but solenoid not throwing it, so it's just doing nothing, turning in its housing instead of grabbing the flywheel.
It was very cold out though.
I gave the starter some light taps with the end of a broom handle to see if it was jammed, when I say light I mean light, I don't wanna break anything...
So to summarize
1. GP light comes in when engine running.
2. Screeching belt noise when GP light on, stops when GP goes off.
3. Engine dies, with or without GP light (fires right back up though)
4. Clunk clunk clunk like a blinker, GP relay acting up.
5. Starter grinding noise (I suspect it stays in it housing turning because there is no sign of life from the engine)
Questions:
Glow plugs shouldn't turn on when engine is warm at all, am I right?
Could the belt screeching noise be caused by the broken 8th glow plug I mentioned? They're AC delcos, just to mention that.
Could the GP electrical issue cause the engine to die? Sometimes when in park to warm it up a bit, I give the accelerator some taps (light) and it'll kill the engine too, start right back up. I know 6.2s are slow and gradual, and I shouldn't Rev jt at all in park.
Clunk clunk clunk, would that be a relay issue? Because I figured out that the GP relay is the piece on the fender, there's also the GP controller which is tucked between firewall and engine block (sort of behind the air cleaner area). Is this something that has happened to any of you, is the relay the issue or the controller? Evidence seems to be pointing at the relay from my findings... I hear it's not uncommon to replace either.
And lastly, would the clunking blinking GP relay lead to the starter not throwing? Since I believe the batteries divert power to the GPs upon turning the key , once their cycle is complete, then power goes to the starter motor for start up of the engine. 12v system.
Or is a proper cycle of the GPs necessary for starter to work properly, like a start permissive or "interlock" if you will. Because i dunno bout all that being around in the 80s.
Anyways, if you made it this far, I appreciate you taking the time to read. I did some youtubing to seenifnother reported the same issue but, seems to be very popular to put a manual GP switch instead of the stock OEM one, if you want to leave your thoughts on what you guys have and if its worth the switch, I'd love to hear your thoughts!
Thanks everyone,