97 Silverado 5.7 4l60e 2wd unknown mileage. Engine harness has been gone through and repaired and re-taped/loomed. Verified all connections. The following issues were present before and have not changed after. This all may very well be PCM related. I don’t know the history of the truck before I bought it but I have seen signs of it being a rough past. When I had a Snapon scan tool the PCM showed it being a 5.0. The vin matches but the engine was a 5.7 (I have since replaced with another unknown mileage 5.7) the transmission has a GM Goodwrench sticker on the top of the bell housing.
So there’s a few things I’d like to take care of before I do the 411 swap. I’ve spent days scouring through posts and my eyes have glazed over.
EDIT: I found the hummingbird gauge thread, I’ll either fix or replace all 4 motors or just get a new cluster
Fuel level, volt, coolant temp and oil pressure gauges bounce, flutter, buzz sway, tick and every movement in between while driving and sometimes at idle. Part of proactive maintenance I have replaced Oil pressure and coolant temp sensor (issues were present before and after) fuel pump and sender have been replaced. Alternator replaced with AD244.
This second thing is really weird and very random/seldom. I know it does it during the day but it’s noticeable at night.
So it’s like a glitch in the matrix, ALL gauges drop and lights flicker off but it’s only for less than half a second. Actual engine RPM does not appear to drop.
I’m unable to duplicate it. I’ve done the wiggle wire dance, I’ve hit bumps and wash boards, I’ve smacked the PCM. Like I stated earlier this issue was present before repairing the harness and has not changed after. For the longest time I thought I was falling asleep or having a seizure or something.
Let me preface this third thing by saying I live out in the country and have a half mile “driveway” that I idle the entire way down.
With that being said, every once in a while when coming to a complete stop after idling the engine RPMs will drop to below 400 for a second then come back up to 750.
Lastly most of the time but not always, when the engine is cold and I put it into gear, the engine revs up to almost 1500. Like my foots on the gas accelerating, it will shift into second at idle. I’ve spun the tires on wet concrete at idle. I’ve read the IAC could be an issue (it’s been sprayed out with carb cleaner a few times) and I’ve read the PRNDL switch could be the issue (I remember having a really hard time getting the harness unplugged from it when I pulled the engine out, like the connector was glued in)
I know it’s a lot to read and I appreciate y’all taking the time to help a brotha out.
Here’s some random pictures to look at
So there’s a few things I’d like to take care of before I do the 411 swap. I’ve spent days scouring through posts and my eyes have glazed over.
EDIT: I found the hummingbird gauge thread, I’ll either fix or replace all 4 motors or just get a new cluster
Fuel level, volt, coolant temp and oil pressure gauges bounce, flutter, buzz sway, tick and every movement in between while driving and sometimes at idle. Part of proactive maintenance I have replaced Oil pressure and coolant temp sensor (issues were present before and after) fuel pump and sender have been replaced. Alternator replaced with AD244.
This second thing is really weird and very random/seldom. I know it does it during the day but it’s noticeable at night.
So it’s like a glitch in the matrix, ALL gauges drop and lights flicker off but it’s only for less than half a second. Actual engine RPM does not appear to drop.
I’m unable to duplicate it. I’ve done the wiggle wire dance, I’ve hit bumps and wash boards, I’ve smacked the PCM. Like I stated earlier this issue was present before repairing the harness and has not changed after. For the longest time I thought I was falling asleep or having a seizure or something.
Let me preface this third thing by saying I live out in the country and have a half mile “driveway” that I idle the entire way down.
With that being said, every once in a while when coming to a complete stop after idling the engine RPMs will drop to below 400 for a second then come back up to 750.
Lastly most of the time but not always, when the engine is cold and I put it into gear, the engine revs up to almost 1500. Like my foots on the gas accelerating, it will shift into second at idle. I’ve spun the tires on wet concrete at idle. I’ve read the IAC could be an issue (it’s been sprayed out with carb cleaner a few times) and I’ve read the PRNDL switch could be the issue (I remember having a really hard time getting the harness unplugged from it when I pulled the engine out, like the connector was glued in)
I know it’s a lot to read and I appreciate y’all taking the time to help a brotha out.
Here’s some random pictures to look at
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