[Commando]

Ok I've been searching and searching for the past week or two and have yet to find the answer or solve my problem. Here's the deal, I have an 05 Canyon w/ the 3.5l, I was installing a new aftermarket intake tube only replacing the resonator box, got everything put back together and took it for a test drive. Truck felt great, no problems, everything seemed perfect but when I parked the truck I noticed the idle felt horrible so I look under the hood to find that the hose from the valve cover to the intake had come loose and was open so I immediately hooked it back up. Still rough idle. I then took the intake off and reinstalled the stock resonator box, still nothing. I pulled the exhaust cam actuator sensor being my symptoms sounded like that was the problem and sure enough one of the screens was missing. I then replaced the ECAS with a brand new one, still rough idle! So I finally decided to take it in to the dealership to see if they could test it thinking it could be the head but the mechanic (after testing the truck) told me it was the exhaust cam actuator and something about my timing being off at idle. Not the part that everyone replaces but the actuator itself. I have no clue what part he's referring to and he couldn't provide me with a part number for some reason so I then took the truck home because they wanted another $380 to run more tests just to try to find out for sure the problem..

After taking it back home, here are some of my tests/replaced parts:

Compression test:
Cyl #1 210
Cyl #2 215
Cyl #3 200
Cyl #4 210
Cyl #5 210

• Found a leaf stuck in my MAF so I carefully pulled it out and cleaned the MAF w/ sensor safe MAF cleaner.
• Changed spark plugs (AC Delco iridium)
• Seafoam'd gas, oil, and vacuum lines
• Cleaned throttle body
• Changed exhaust cam actuator sensor (as noted above)

Results:

Truck idles SLIGHTLY better.. It still feels like it's either got a huge cam or a terrible miss and the truck idles like shit, shaking pretty bad.. Once I take off the truck is fine, I didn't have much of a loss in fuel economy, doesn't miss, nothing. Only thing that seems off is that the VVT doesn't seem like it's kicking in. Either that or the truck just has some loss in power in the high rpms but it's not a huge loss, just noticeable. Is there maybe a chance I got a faulty ECAS from the parts store? Idk what else would cause this problem and I really need this fixed ASAP. Any and all suggestions are gladly welcomed. Thanks 355!

 

[Commando]

Ok well here's another rundown and a little background so you know you aren't dealing with a n00b lol, I've been building cars since I was 15 and I'm 24 now. I've owned probably 20-25 different vehicles, not one bought by mommy and daddy so I've always taken pride in anything I've owned, I've built two motors from the ground up full builds and I've worked on countless.. Now with that being said, you're absolutely correct on doing the repairs individually which I did in fact do. I would "fix" one thing, test drive it, clear codes, then try the next "fix" and repeat..

I used CRC mass air flow sensor cleaner for the MAF and CRC throttle body cleaner for the TB and I've never had issues in the past with either.. And I immediately took off the aftermarket tube as soon as I got back from test driving with it on. I've had the stock resonator box on ever since and that was the only part I changed before it started having the issues.. All the other parts were changed trying to solve the problem.

That's the only reason I feel like whatever happened had to be either a result of my truck not liking the aftermarket tube or a strange coincidence.. The one and only part I changed at the time, I immediately reversed and put the stock part back on after the problem started but it didn't fix the problem. I just got home from work and the battery cables are off and I have about another 15 minutes before I'm going to reconnect them hoping to reset the computer and praying it fixes itself.. Sadly I don't see it fixing itself but my fingers are still crossed so we'll know soon enough..

Another question, what does that piece connected to the end of the exhaust cam sprocket do exactly? I remember reading a little about it but it wasn't very informative but from what I gathered it seemed like it could potentially send a signal or not send a signal when it's supposed to or something throwing timing off and potentially causing a miss at idle..

And last just to make sure, there are only two ports that need to be connected to the stock resonator correct? One goes from the valve cover to the resonator box and the other from the fpr to the box? Just covering my bases and making sure I have everything connected correctly.

Thanks for the help!!

 

[Commando]

Ok well here's another rundown and a little background so you know you aren't dealing with a n00b lol, I've been building cars since I was 15 and I'm 24 now. I've owned probably 20-25 different vehicles, not one bought by mommy and daddy so I've always taken pride in anything I've owned, I've built two motors from the ground up full builds and I've worked on countless.. Now with that being said, you're absolutely correct on doing the repairs individually which I did in fact do. I would "fix" one thing, test drive it, clear codes, then try the next "fix" and repeat..

I used CRC mass air flow sensor cleaner for the MAF and CRC throttle body cleaner for the TB and I've never had issues in the past with either.. And I immediately took off the aftermarket tube as soon as I got back from test driving with it on. I've had the stock resonator box on ever since and that was the only part I changed before it started having the issues.. All the other parts were changed trying to solve the problem.

That's the only reason I feel like whatever happened had to be either a result of my truck not liking the aftermarket tube or a strange coincidence.. The one and only part I changed at the time, I immediately reversed and put the stock part back on after the problem started but it didn't fix the problem. I just got home from work and the battery cables are off and I have about another 15 minutes before I'm going to reconnect them hoping to reset the computer and praying it fixes itself.. Sadly I don't see it fixing itself but my fingers are still crossed so we'll know soon enough..

Another question, what does that piece connected to the end of the exhaust cam sprocket do exactly? I remember reading a little about it but it wasn't very informative but from what I gathered it seemed like it could potentially send a signal or not send a signal when it's supposed to or something throwing timing off and potentially causing a miss at idle..

And last just to make sure, there are only two ports that need to be connected to the stock resonator correct? One goes from the valve cover to the resonator box and the other from the fpr to the box? Just covering my bases and making sure I have everything connected correctly.

Thanks for the help!!

 

[Commando]

Well I reset the PCM by removing the cables from the battery for 30 minutes and at first my truck kinda freaked out and wouldn't start, it wouldn't even turn over. All I got was a few clicks like the battery was dead so I cleaned the terminals and she fired right up.


But the problem is still there....


I'm gonna drive it a couple days and hopefully it'll relearn how to act right.. Lol

Any tuners in Houston area or south of Houston? Maybe they could tune out my issue while me picking up a few ponies in the process


I know of a few shops that tune imports but none really that deal with domestics much..

 

[Commando]

Thanks fixxxer, I appreciate the help, and currently the idle is jumping around 500-700 and it sounds very much like a cammed v8 would as far as the idle lope.. I may try to upload a video and show you what I'm talking about but I imagine if you unplugged a coil pack you'd get similar results.. Sometimes it gets so bad that the engine shudders and shakes the whole truck. Well worse than it already shakes anyways.. I drove the truck a good 70-80 miles tonight taking the gf out to dinner and the check engine light came back on so I'm going to check it out tomorrow and see what code it's throwing now.. Before I was getting the p0300, p0171 and p0017 (random misfire, lean bank 1, and cam/crank position sensor bank 1 sensor B) I was also getting MAF but I'm about 99.9% sure that was from the leaf I pulled out. Well hopefully I figure out something soon. Thanks for all the help so far everyone and please keep the suggestions coming!

 

[Commando]

Video of crappy idle:
http://i112.photobucket.com/albums/n194/dimeboy/604883f1.mp4

 

[Commando]

Ok well here's an update, it just started idling fine on cold starts for about the first 45 seconds to a minute and then the jumping idle comes back.. Now what I'm trying to figure out is why it would only start doing this now after 91k miles and only after messing with the intake but immediately returning it back to stock literally within a 30 minute or less time frame.. I'm going to pull the codes here in about an hour and see if anything new has popped up..


Fml...

 

[Commando]

Fixxxer, is the CMP actuator that you're referring to the ECAS or the VVT actuator on the exhaust cam sprocket? Because I believe the VVT actuator is what the dealership was trying to tell me was shot.. Well, from their diagnosis at least that was the mechanic's best idea of what the problem was.. If that's the case, has anyone on here successfully removed the cam sprocket and kept their timing right without having to pull the front cover? I know gm makes special tools to wedge the tensioner and hold the timing chain in place but the dealer mechanic told me it's not uncommon for people to install the tool wrong and have to completely reset the timing.. He even told me he wasn't sure that he could get the tool wedged just right therefor creating a 16hr job..

 

[Commando]

Well banditz if you still have the sensors and they're good, I'd gladly pay for shipping to swap them out and see if it fixes anything.. I mean worst case scenario I spent a couple bucks and I'll still be in the same boat but if it fixes my problem I say a couple bucks extremely well spent..

And yes fixxxer, you're correct about the VVT actuator I was talking about.. And the only reason I think that might be the culprit (other than the dealer mechanic telling me that's what he thinks it is) is because at WOT, it just doesn't have the same pull or even sound like it used to as if the VVT isn't working and the extra valves aren't opening on the higher rpms. Now idk if those open from a solenoid and maybe the actuator sends signal to operate them or what but I know that my top end power seems to have died some..

Get back to me on those sensors/solenoids banditz please sir!

 

[Commando]

Now I never said the I5 sucks, I actually think it's a great motor, it just has a few bugs that gm needed to work out.. Which I think many of them were addressed with the 3.7 but even the 3.7 has room for improvement.. But then again that's what we're on this site for right? To learn more about our trucks and modify them to make them better in some way?

 

[Commando]

Now showing P0068, P0106, P0300 and P0017

Map, map, random misfire and crank sensor...

I wiggled my map and MAF wires, no change, pulled map plug, truck idled higher, smoothed out like it was almost perfect then back to shitty. Plugged it back in, truck stumbled then back to shitty.. Lol

Possibly bad map or MAF? Would one of those cause the terrible miss I have at idle?

 

[Commando]

Swapped out the map sensor for a brand new one, no dice.. Absolutely no change

Is it possible that I need to have my PCM reflashed* or updated? The only things I know to change are my cam sensors, then the VVT actuator.. Other than that I'm just about out of ideas and I'm just now getting familiar with the 3.5 so it's really aggravating when I can't even figure out exactly what my issue is. I want my truck running perfect again!!

 

[Commando]

Time for a v8 :lol: if you need any parts as well I have a 3.5 laying here with parts parts and more parts lol

Funny you say that, when I ran the compression test a buddy of mine called his dad for a hook-up and he can get me a very low mileage 5.3 with trans, harness and accessories for about $900 (he works for insurance claims and has access to ridiculous deals), so I've considered the swap around income tax time

Was your 3.5 running properly when pulled? If so, how much for the exhaust cam sprocket with the actuator on the end? That and the exaust cam sensor (the one on the front of the engine, not the ECAS). Pm me please sir! Thanks!

 

[Commando]

Ok fixxxer check this out, I know for a fact I've got the hose connected good under the resonator box, I've double, triple and quadruple checked it haha, however, I can hear a hissing like a vacuum leak on the driver's side and it sounds close to the manifold or the brake booster but idk if that's normal because I can't find anything loose. The first thing I thought myself was vacuum leak too, I just can't seem to find it. I'm considering making a boost leak tester and using that to possibly find the leak, I don't see why that wouldn't work.

As far as the sensor, I'm going to call the parts shop in a few and see if they have it, that was actually next on my try-it list.. Lol

Thanks for all the help guys, hopefully I can get this issue resolved soon..

 

[Commando]

Well vatozone has the cam sensor in stock, I'm going to pick it up after work and see how things go from there, wish me luck!

If that's not the fix I'll be building a boost leak tester and see about a vacuum leak in the manifold

 

[Commando]

Well I replaced the cam sensor and initially it seemed to ssomewhat smooth out the idle, not a lot, but a little but after driving it a few miles it's back to the way it was. I currently have the battery and pcmb fuse pulled and I'm going to try to reset everything again and see how that works but I'm with you ssgjurista, I think it's the VVT actuator..

I've also been reading about people stretching their timing chains, what is the likeliness of that happening and throwing something off? It really just seems like my timing is a good bit off.. Could I have jumped a tooth somehow? On my last car I had 2-row timing chain and gears with a badass tensioner and guides so it was basically impossible but I'm still learning about these i5's

 

[Commando]

Ok so now I'm basically down to the VVT actuator if this sensor does nothing after resetting the pcm

Thanks for the info banditz

 

[Commando]

Resetting it did nothing, the idle is exactly as it was before changing the sensor.. Anyone wanna sell me a good VVT actuator so I don't spend $170 on a new one that MIGHT fix my problem?

 

[Commando]

Finally bought a new (used but working) VVT actuator and will be installing here in about an hour. Hopefully all goes well. I heard something about possibly having to get the PCM reflashed or else my timing will still be off even if I change the sprocket/actuator. Can anyone confirm or deny this claim? It would be very beneficial to know because if that's the case I'll most likely just get the truck tuned at the same time..

 

[Commando]

Well I've already replaced the exhaust cam sensor, the map, cleaned the MAF, cleaned the t/b, replaced the ECAS, reset the computer, changed the plugs, fixed the valve cover to resonator hose, absolutely everything I can think of other than the VVT actuator itself which the dealership originally told me was the problem anyways so who knows, maybe they were right.. And if they are and I swap it out and the truck runs great again, M_O_Z is my new best friend for selling me a good VVT actuator for a good price. Lol

I just hope this fixes my issue because as soon as I get this sorted out I'm going to start ordering parts for the truck.. New wheels/tires, lift, HIDs, PTB, gutted primary cat, etc etc.. Not all at once of course but at least after I take care of the motor I can start building the truck the way I want it..