Motrhedx81
Newbie
I have a weird issue with the 454 in my 2000 GMC K3500. I've been racking my brain for a long time. When I watch it idle at the tail pipes it will suck a rag in and out on the right bank, but not the left bank (left seems to run fine). It acts just like what's happening in the video linked below. I've had it for a little over a year and did a lot of work when I got it. It has about 195k miles.
Rebuilt the heads (3 angle valve job, decked, new seals)
New Bosch 19lb injectors
New pressure regulator
New distributor, plugs, wires, coil
New O2 sensors
New fuel pump and filter
New coolant temp sensor
Cleaned MAF and IAC
Gutted catalytic converters (one was broken up already)
True dual exhaust (helped I'd which bank the issue is on)
Compression test was all around 150 psi before I did all the work. Leak down was pretty bad, which led me to do the heads, but I haven't rerun the leak down yet.
Engine doesn't smoke at all (that I've seen). It does run a little rich (I can smell it). Makes sense that it would if the the O2 sensor is reading extra oxygen from the sucking. I did run an infrared temp gauge/sensor on the manifolds one time and the right bank was not getting as hot or consistent as the left.
It runs good, relatively speaking, except for this weird issue. I'm down to thinking bad lifters or bad cam. Bad valve springs are a possibility but unlikely, I think, due to having the heads rebuilt. I would think a bad timing chain would cause issues on both sides.
Any thoughts? Has anyone seen this before? I posted to this video but never got a response to what the end resolution was.
Rebuilt the heads (3 angle valve job, decked, new seals)
New Bosch 19lb injectors
New pressure regulator
New distributor, plugs, wires, coil
New O2 sensors
New fuel pump and filter
New coolant temp sensor
Cleaned MAF and IAC
Gutted catalytic converters (one was broken up already)
True dual exhaust (helped I'd which bank the issue is on)
Compression test was all around 150 psi before I did all the work. Leak down was pretty bad, which led me to do the heads, but I haven't rerun the leak down yet.
Engine doesn't smoke at all (that I've seen). It does run a little rich (I can smell it). Makes sense that it would if the the O2 sensor is reading extra oxygen from the sucking. I did run an infrared temp gauge/sensor on the manifolds one time and the right bank was not getting as hot or consistent as the left.
It runs good, relatively speaking, except for this weird issue. I'm down to thinking bad lifters or bad cam. Bad valve springs are a possibility but unlikely, I think, due to having the heads rebuilt. I would think a bad timing chain would cause issues on both sides.
Any thoughts? Has anyone seen this before? I posted to this video but never got a response to what the end resolution was.
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