[mcseth16]

Was getting P0017 every now and then on my 2005 Chevy Colorado 3.5l with 113k and now it comes on regularly after being cleared. Changed the valve solenoid of course and the code came back. Had this same code a year ago and changing the solenoid fixed it. Seems the problem has worsened. Does changing the cam sensors or o2 generally fix this problem, or is that rare? After some research is seems I might be going down the road of a timing change job or maybe just flushing the engine with sea foam? Engine runs fine and performance doesn’t seem to be affected. Any ideas?

 

[Colly_shifter]

You can watch all of them (there are 5 videos of the entire case study) to get a better understanding of what's happening, but this guy's case study explains it in far greater detail than I can.

TLDR version: GM put the timing tighter than a virgin cheerleader on prom night via the PCM's programming. After so many miles, near 200k I'd say, the timing chain gets stretched, the chain guides wear and it pops the code non-stop until you overhaul the engine's timing set. The engine will run and may even do so well enough, but it's fuel economy and performance will certainly wane the longer this goes on.

 

[mcseth16]

You can watch all of them (there are 5 videos of the entire case study) to get a better understanding of what's happening, but this guy's case study explains it in far greater detail than I can.

TLDR version: GM put the timing tighter than a virgin cheerleader on prom night via the PCM's programming. After so many miles, near 200k I'd say, the timing chain gets stretched, the chain guides wear and it pops the code non-stop until you overhaul the engine's timing set. The engine will run and may even do so well enough, but it's fuel economy and performance will certainly wane the longer this goes on.

So from a rebuild standpoint... isn’t it more man hours to re-do the timing chain and everything along with it than to just replace the engine? Just trying to think about options and if it’s even worth rebuilding the engine vs getting a different one.

 

[Colly_shifter]

So from a rebuild standpoint... isn’t it more man hours to re-do the timing chain and everything along with it than to just replace the engine? Just trying to think about options and if it’s even worth rebuilding the engine vs getting a different one.

You could try to find a gently used 2007 3.7L I-5 from a junkyard/parts dealer near your area on car-part.com. Hummers, Isuzu I-Series trucks and Canyons along with your Chevy all use the same engine for those years, 2007 through 2010, that should make it a bit easier to find one. That particular year model engine will retrofit into your existing truck without too much hassle, albeit there are a few extra things you'd have to do to make it work, any other year model engines will be much more difficult to retrofit but can be done. The 3.7L I-5 would be a nice upgrade in power (220 hp vs. 242 hp) and overall reliability I'd say though. Otherwise, your only other option is a rebuild or at least, replacing the timing set and guides. Hope this helps, good luck!

 

[Kenzen]

Just an idea...the p0017 code is thrown for various reasons, oil pressure being one of them. As I've read the many discussions and watched the videos on the repair, ive noted a necessary step is to drop the oil pan for access to the timing chain. In doing this I assume the mechanic is cleaning out the pan and the oil pickup tube. If you have a sludge problem, which is common in our engines, the effect of low oil pressure due to the sludge could reduce the effectiveness of the timing chain tensioner, and/or the operation of the cam phase actuator. What are the odds your oil pickup has been accumulating sludge, making your oil pressure gradually drop, and increasing the frequency of the p0017 CEL?

 

[mcseth16]

Just an idea...the p0017 code is thrown for various reasons, oil pressure being one of them. As I've read the many discussions and watched the videos on the repair, ive noted a necessary step is to drop the oil pan for access to the timing chain. In doing this I assume the mechanic is cleaning out the pan and the oil pickup tube. If you have a sludge problem, which is common in our engines, the effect of low oil pressure due to the sludge could reduce the effectiveness of the timing chain tensioner, and/or the operation of the cam phase actuator. What are the odds your oil pickup has been accumulating sludge, making your oil pressure gradually drop, and increasing the frequency of the p0017 CEL?

Actually a high chance of being the issue. I recently moved and don’t have to drive the truck much anymore so I think it doesn’t fully warm up very often possibly causing sludge. Would seafoam solve that?

 

[Kenzen]

There's 101 recommendations out there for chemicals to do this, but the right way is to drop the pan. There's the risk it gets worse, or even clogs the screen and trashes your engine with a flush. I'm in the same boat right now, and waiting for warmer weather to work it.

 

[mcseth16]

There's 101 recommendations out there for chemicals to do this, but the right way is to drop the pan. There's the risk it gets worse, or even clogs the screen and trashes your engine with a flush. I'm in the same boat right now, and waiting for warmer weather to work it.

Just an FYI. I had a trusted shop do a thorough run down and it turns out my cam phaser is not actuating 100% of the time when it should be. Possible causes, they think, is it is gunked up and they recommend running ATF through the engine oil. Or, it has a metal screen or other metal bits locking it up from a past variable valve solenoid losing a screen, since it been replaced a few times on my truck, which would mean it needs to be replaced. I got quoted $2,200 for the cam phaser replacement. Trying ATF first though.

 

[Kenzen]

ATF and kerosene are the "old school" techniques that are still very effective and conveniently cheap. I highly recommend you get an idea of how much sludge is in that engine before you start- look down through the oil fill hole and see what is caked around the top of the timing chain and the cam phaser. If you have a lot of gunk, the ATF might unleash a lot of stuff and wind up in the pickup screen in the oil pan. You may want to pull the valve cover and manually clean out the gunk around the cams first. I'd run that ATF cocktail under close supervision, with an oil pressure gauge attached if possible, in the shop for 30 minutes or more at maybe 2000 RPM or so, and carefully inspect what comes out of the oil pan and into the filter. I'd pull the cam phaser solenoid as well to clean the screens. If the oil coming out is black and clumpy do it again. When you are done, you can still find yourself with sludge just sitting/sticking in the pan, and with the right movement of the truck (running hot and fast with a quick slow down - my experience), it loosens up and drifts into the oil pickup screen - very bad.

There's a recommendation out on the web on a forum somewhere (sorry I'm going on memory) where a guy recommended draining all the oil out, and through the dipstick tube putting a gallon of carburetor cleaner in the oil pan for a few days, just to sit there - not run the engine!!!! It has to go in through the dipstick tube so it doesn't touch seals because the cleaner will destroy them. After a few days, the cleaner is drained and the pan and oil pickup will be "shiny and clean as new". Then he recommended putting a gallon of kerosene in the oil pan for a little while, just to rinse the carb cleaner out. The he filled with fresh oil and ATF (and a new filter if old), ran that in the engine for a while (like above), and then put a fresh oil change/filter in. This was all motivated to avoid taking the oil pan off since like our trucks, its a PITA.

I provide this for your consideration - my truck is sitting in a garage (3 hours away) with an oil pressure problem and I either have to tow it home to pull it apart, or do something like the ATF to clean up the system to make it driveable. Either way, my S10 is serving me well at this time so I'll get to it when it warms up and hopefully the world is a little less crazy...

Best wishes!