Any chance you moved the timing chain on the sprockets? Did you remove the OCVs or just lean the cams? Oil soak the lifters before install? Are you sure all rockers were properly seated on both the lifters and valves?

 

Check your new rockers they don't match up

 

I followed Motor City Mechanic's directions, which included rotating the cams to a specific position aligned with timing marks, using blocks to lock the sprockets in place, and then wedges to release the chain tensioners. I removed the cams from the cam phasers and only worked on one cam at a time. I soaked the lifters and rocker arms for about 5 minutes (and stirred w/ a screwdriver until I didn't see any more bubbles) before installing.

I used a paint marker on the cam phasers, top chain link, and then the first cam cap for alignment. I double checked before putting the valve covers back on that all the rockers were properly seated on both the lifters and valves. I can turn the motor by hand on the crank, and it spins the motor when I turn the key. If any of these were off, would it have the symptoms I'm describing?

 

Frankly with a job that requires quite a lot of things being disconnected it's hard to say where you could have made a mistake.....
I did just do the same on my 2014 caravan. Used same 3 part video from motor city mechanic- it's very detailed video. Replaced 4 camshaft and all rockers/ lifters.
Started up engine and built oil pressure in 2 seconds.
Maybe you forgot to connect a sensor somewhere? I would imagine that will light up a code....
If you didn't put the wrong camshaft in the wrong place and you marked wheel and chain positions....no reason not to start.
Sorry I couldn't be helpful.

 

Is the 3.6 an interference engine?

 

The google machine tells me yes. I would think if I screwed up the timing chain or cam sprokets my hand cranking would seize, and/or the starter spinning the motor would have grenaded or something. There have been no "bad" sounding noises like something hitting something it shouldn't, but I'm not ASE certified, I'm YouTube certified, and barely that.

Are the coilpaks fully seated and plugged in?
Are the fuel injector connectors plugged in? Sounds like you already checked these.

The coilpacks should be fully seated, and unfortunately with the 3.6 they're under the upper intake manifold so I can't check them all without tearing back in. I plan to take the upper intake manifold back off in the next couple of days to triple check the connectors I can't really fiddle with. I plan to unplug all of them and check to be sure no pins look bent, too. They all went in and clicked so I doubt it's that, but I want to eliminate possibilities. I removed the battery for the repair, but I still plan to check fuses.

Is there fuel flow?
Do you smell fuel while doing this?

I'm not sure if there's fuel flow. Unfortunately the fuel rail doesn't have a pressure port (like a schrader or anything) so I guess to test that, I'll take the supply line back off of the rail and see if there's plenty of fuel there leaking out like when I started the repair. I feel like I smell fuel after attempting to start, but there's also brake clean, and other smells in the garage right now so I might just be smelling that. I'll open the garage up and air it out before trying again to see if I smell fuel.

 

Are the coilpaks fully seated and plugged in?
Are the fuel injector connectors plugged in? Sounds like you already checked these.

Is there fuel flow?
Do you smell fuel while doing this?

 

I think it’d be really smart to do a compression test. Your description of how it sounds when cranking makes it sound like it has no compression.

 

I don't have a compression tester... I'm tempted to just pull the valve cover again if I'm tearing back in, but I'm concerned with re-using the seal based on the 2 spots of RTV where the timing cover and heads meet. Pulling that either means chancing an oil leak there, or another ~$50 on a gasket, but an OTC compression tester is ~$100. Hmm....

Any codes? Check engine light? Could you have left a rag in the intake?

No codes or CEL. I used blue shop towels in the head passages. I know I pulled them all before putting the lower intake back on because I looked through at the valves I could see on each cylinder.

Something I didn't do, but maybe should have in retrospect, was hand-crank the motor with the valve cover off to see if everything looked OK... i.e. cams turning, rockers moving, valves opening/closing.

I'm really hoping for somebody that really knows this motor to say something like "oh, if a CPS is bad, it won't even try to ignite" or something.

Couple of questions:
Can you safely spray brake clean on CPS (not in the connector, but around the top, where I had some "grime") and the spray port of the injectors. I got brake clean on those things when cleaning them before inserting the new gaskets and buttoning things up. I don't think there should be any issues, but you never know.

I also added new oil pressure sensor and oil temp sensor on the oil cooler when I was in there, could brand new MOPAR ones be bad, causing this type of issue?

 

Any codes? Check engine light? Could you have left a rag in the intake?

 

The fact that you are not getting any (zero) sputter when cranking makes me guess that there's no fuel or no spark or both. Just my guess.

 

I agree. I'm trying to think if the starting sequence would have a flow like:
1. Engage starter
2. Wait for reference crank position signal/cam position signal.
3. Start sending signals for fuel/spark

In other words, maybe some wiring is my problem, and it's not getting past step 2, and not necessarily the valvetrain.

Another tidbit with this motor. I replaced the valve body in the transmission at the beginning of the year due to the 2-4 solenoid being bad. Afterwards I was getting an intermittent code for the MAP that indicated a problem including a potential vacuum leak and it would go into some form of a limp mode. It wouldn't downshift, and couldn't use cruise, but I could still go full speed. I replaced the manifolds, vacuum lines, MAP sensor, and the MAP connector. That still didn't fix it, so I took it to the dealership who found a bad wire deep in a harness. I'm really hoping that when I moved the harnesses out of the way for this work another brittle wire didn't break.

 

Should have CEL and if you forgot to plug back say a cam sensor it should indicate.

I think the 2 sensors on the intake and exhaust the Youtube Mechanics say not to mix them, maybe you did that.

If the engine does not know where the motor is for example firing order it wont know where to send spark or fuel so it wont start.

 

I think the 2 sensors on the intake and exhaust the Youtube Mechanics say not to mix them, maybe you did that.

If you mean the cam actuators, I labeled them with a paint pen using dots and put them back where they came from. However, if you mean the cam position sensors on either bank, those are the one thing I didn't label and could have maybe mixed up, but I'm pretty sure I didn't based on the grime on one vs. the other which I cleaned right before putting back. My left bank has slight oil seepage, but the right didn't.

 

Have you done the basics for troubleshooting a no start? Spray a little fuel down the throat and try it? Pull a plug wire[coil] install a plug and hold against the block to look for spark?
You have either.....no compression, no spark or no fuel.

 

Fuel pump (TIPM) control may have picked the magical wrong time to go.

Again, having no cough or sputter when cranking...... and you can't tell the diff from brake cleaner (Fuel smells entirely different).

 

sorry i cant be of any help, i was thinking about attempting the rocker fix myself as i posted on this forum about some opinions. The scenario you are in is like my nightmare. I wish you best of luck and hope you resolve it without driving yourself insane

 

Thank you! I fought with that decision too. I've done some work on this motor before, but never to the valvetrain. Good luck with your decision. I was kinda rushed into this. I took the van in for an oil change and they cracked the oil cooler and denied any fault. It was literally spewing oil all over so I had to either get it fixed, or fix it myself. The dealer wanted over $1k for the oil cooler job so I was tearing in to do that myself (that's a relatively easy job) and figured since I was tearing in already, might as well get rid of that tick and do that work myself too. I ordered up all the parts and dove in. I found one of the exhaust rockers on the right bank that was completely shot so I'm confident that was the tick I had, but with re-assembly, I'm just hoping I didn't screw something up that I can't easily fix myself. I replaced all 24 rockers/lifters and took my time over a couple days. I'm an engineer, but not a mechanic. I wrote out torque specs/order, and any time I second guessed anything, I'd stop and investigate. The two hardest part of the job for me (aside from the current non-working state of things) was getting tension released properly on the right bank. The tool I bought didn't seem to want to give me much play on that chain and the intake cam was a little difficult to get in and out. I took my time, and things seemed good when I put it back together, but something is definitely wrong. I am leaning toward some sort of compression problem based on the advice here, symptoms themselves, and watching a couple other videos for similar sounds to the way it's cranking. It sounds so "loose" I thought the starter solenoid wasn't actually engaging the motor, but I can see the serpentine belt (and pulleys) move when it cranks, it just sounds so "free" like the motor isn't even doing anything so maybe some valves are stuck open, but it's an interference motor, so I don't know what exactly could be going on.

I'll report back what I find out, but I already ordered another valve cover gasket set and will tear back in this weekend to see if I can figure anything out. The local shop wanted $2900 to do this job, so I'm fine spending another $50 on the mahle gasket set and tearing back in for now. I was about $600 in, for quality replacement parts (mopar oil cooler (and new sensors), mahle gaskets, melling rockers/lifters, $20 chinese cam/timing blocks from amazon) and now an additional $42 on another gasket set, and for the heck of it I bought a OTC compression tester that will be here tomorrow to add to my toolbox. Another reason I'm willing to keep fighting this is I bought a second vehicle with this motor recently, so I'm considering any learnings I get as an investment.

 

I had the wife crank the engine while looking at the serp belt today, which spun, and I didn't have her crank it very long, but I didn't smell any fuel. How long would I need to attempt cranking to hear that? I looked at some information on the TIPM and fuel problem, seems somewhat common and there's a couple easy ways to test that the relay/pump are at least getting/sending power when they should, which I'll do this weekend, too. The good news is if that's the problem, (which I doubt, since it doesn't "chug" when cranking, just sounds like it's free-spinning) it can be fixed for way less than the $1200 a TIPM costs.

 

To " smell" gasoline while cranking....remove 1 spark plug and see if fuel smell comes out of the hole when cranking. Don't burn yourself!!!! Cut off spark plugs wires.
I imagine it would be hard smelling fuel otherwise....unless you crank forever and soak engine and catalytic converter completely.....which is no good.

 

I watched about 10 videos, 1 very detailed one and to me it seems like it would be doable but there are just some certain parts (like tension on the chain etc etc) that the videos make look somewhat easy but i know from doing house remodel work it just never works out that way. I have been getting more quotes like some of the forum peeps have suggested and everyong is around 3k for my area. Some places will let me buy the parts which will save me almost 1k but they wont warranty it and i just dont feel like if there is a problem the finger pointing would start. Still debating what to do.. but i love my van 200k+ owes me nothing.

 

I’ll give you a head’s up on the possibilities if it has no (or very low) compression. Best case would be that the cam timing is off, and fixing that resolves it. Worst case is that valves are bent on all the cylinders with no compression. If they have some compression (even 30 or 40 PSI) the valves aren’t bent.

With the valve covers off, see if any rocker arms are very loose. If they are, valves are almost for sure bent. It’s more common for intake valves to bend, because they’re bigger and usually stick down more when they’re open.

We’ll keep our fingers crossed and hope it’s not that.

 

If the valves are all bent, presumably that means new head(s)? Would a problem bending the valves make some sort of awful sound? The first time I cranked it, and the last time, it has sounded exactly the same and never made any "bad" (banging/grinding/popping) sounds. More like the lack of sound, really sounds like mostly just the whirring/buzzing of the starter.

 

It doesn’t mean new heads, but it means a valve job on your heads. You wouldn’t necessarily hear anything. It doesn’t take much force to bend valves.

 

Dang, that's not what I was hoping to read. Thanks for the reply. I'll report back when I get time to work on the van again.

 

The rocker tick is louder than valve crash would be. The good news is, your chain can be several links off and still not crash valves. It will run with up to 30 degrees (maybe more, but I'm not trying to find out) offset on a single head and have no symptoms other than a severe lack of power.

When you open the covers, turn the crank to TDC and look at the phasers and make sure you have lines and arrows where they should be. Lines in center on right/rear head and arrows on left/front. Make sure the dot on the phaser collar lines up close to the one on the cam. (It won't be perfect, but should be close. Mine is directly beside.) There are other holes the key pin can fall into, so use these dots to make sure you're in the key hole and not an oil hole. If you got them backwards, you should be fine. It would put the cams about 170 degrees out of phase with the crank, which means mechanically it would be operating almost like normal, but the pulses for the spark and fuel timing would be happening at the wrong times. The valves might have a bit of overlap in this scenario, which would explain your seeming lack of compression during starting.

And a bit of cost saving advice, reuse your old valve cover gaskets without applying RTV until you get the problem sorted, then put your fresh gaskets on. You won't leak much oil doing start attempts.

 

The rocker tick is louder than valve crash would be. The good news is, your chain can be several links off and still not crash valves. It will run with up to 30 degrees (maybe more, but I'm not trying to find out) offset on a single head and have no symptoms other than a severe lack of power.

I really hope I didn't screw up the valves. I'll find out tomorrow.

When you open the covers, turn the crank to TDC and look at the phasers and make sure you have lines and arrows where they should be. Lines in center on right/rear head and arrows on left/front. Make sure the dot on the phaser collar lines up close to the one on the cam. (It won't be perfect, but should be close. Mine is directly beside.) There are other holes the key pin can fall into, so use these dots to make sure you're in the key hole and not an oil hole. If you got them backwards, you should be fine. It would put the cams about 170 degrees out of phase with the crank, which means mechanically it would be operating almost like normal, but the pulses for the spark and fuel timing would be happening at the wrong times. The valves might have a bit of overlap in this scenario, which would explain your seeming lack of compression during starting.

Yikes. I could definitely see that being screwed up, which would suck. I should still have the paint marks to double check everything, but this being off 170° sounds very plausible because I, stupidly, used the key pin on the cam & phaser to line up and didn't pay attention to the dots on the collar because they're tucked back too close to the firewall to really see w/o a mirror on the right exhaust cam. I'll be checking the two right cams first after doing a compression check.

If this is the case, and one of the cams (or both?) are off 170° would would there be any piston/valve contact? Or would I have gotten really lucky?

And a bit of cost saving advice, reuse your old valve cover gaskets without applying RTV until you get the problem sorted, then put your fresh gaskets on. You won't leak much oil doing start attempts.

That is great advice! I'm also looking at doing things in a specific order. Before pulling the valve covers at all, I'm going to do a couple other checks.
First, I'm going to do wiring checks on the fuel pump and fuel pump relay.
Next, I'll pull the upper intake and do a compression test on each cylinder.
Depending on what I find on those will likely determine if I open either or both of the valve covers.
When I put things back together, I'm not going to put the stupid brackets back on the upper intake after torquing until I know the thing is running, those two in front by the radiator, a/c lines, and upper radiator hose are a pain in the butt!

I'll be taking a lot of pictures this time. Last time all I did was snap a quick video of the bad rocker arm before taking off the cam. It was an exhaust valve on cylinder 5.

 

I have a reason for my no-start condition, and more questions.

First I removed the upper intake manifold and all the intake stuff, checked all the wiring and everything looked good. Then I pulled off the fuel injector connectors, ignition coil wires, and pulled the fuel pump fuses. I did a cold compression test, and have exactly 0 compression on all cylinders.

I opened the left bank valve cover again, and everything looks right. I then tried thinking of what could give zero compression on all cylinders and while I was looking at things, thought maybe the valves were never able to fully close. I put the timing chain cam phaser blocks back in on this side after aligning the timing marks, removed the intake cam, and could see that as I was loosening the bearing caps the cam was moving up slightly (after rotating inward 30° to the "rest position", which didn't feel as "loose" as when I was taking out the old rockers/lifters). Then I pulled one lifter and compared against the old ones and my problem was painfully obvious, I didn't even have to get out calipers. I have the wrong lifters. The new ones are probably ~2mm too tall. I checked the order from rockauto and their part selector gave the correct JB7525, but they sent me JB7524 and I didn't notice. I also didn't compare when changing them over because I pulled all 6 for one cam out, set them aside, while the new ones soaked in oil before I installed them. They seem like they're the same diameter, but the wrong ones are taller.

On to the questions:
1. Does this seem like the "smoking gun?" I believe yes.
2. Do you think having these in could have caused any additional damage to the cams, new rockers, cam bearing caps, etc.?
3. Do you think this could have caused any valve to piston contact? (I do have a borescope coming today from Amazon and can look to see it the pistons have any visual markings)

 

I forgot to mention, I definitely had fuel pressure because even with the fuses pulled for the pump for a while, when I was putting the wedge to release timing chain tension on the left bank, the fuel line was in the way and when I disconnected it from the fuel rail gas literally shot all over. 🤦‍♂️

 

Melling JB-7524 Engine Valve Lifter
for your 2006 GMC Envoy 4.2L L6 Gas DOHC

https://www.stockwiseauto.com/melling-jb-7524-engine-valve-lifter?Year=2006&Make=GMC&Model=Envoy

 

Yup. That's what they accidentally sent.

I should have the correct ones next Wednesday. I hope having the wrong ones installed for a few days didn't mess anything up.

 

Big screw up on RockAuto's part. I doubt it caused any damage because this would lessen the amount that the valve extends into the cylinder. Zero compression was probably because the intake valves couldn't open, but the exhaust could.

 

I own a little bit for not double checking that they shipped what I ordered, too.

The wrong lifters were the taller ones, wouldn't that make the valves open more, not less? My fear is that the increased angle of the rocker could wear into the cam a tiny bit, and/or the extra 2.2mm of height (I measured with calipers) caused the valves to open a little deeper into the cylinder.

I'm guessing since it never actually ran just spun a few times, it's probably ok.

Senile and others, thank you for all the help! I really appreciate it!

 

Lifters are on the opposite side of the valves on the rocker...so a longer lifter should mean a shorter valve travel stroke - thus no compression when "closed".
No pushrods in this engine?

 

This is a different animal. You should find a picture of the whole setup. The rocker arm has a roller that rides on the cam.

 

That’s a real bummer. You’re right — the valves would have opened another 2 mm (times the ratio of the rocker arm). You’re just going to have to get it back together and see what you have. The only way to test for bent valves is a leakdown test, and you can’t do that with the timing chains unhooked.

All it takes is two crank revolutions to bend the valves on every cylinder, so it’s wishful thinking that you only cranked it a bit. I’m hoping for the best for you.

 

I really think you would’ve heard a racket while turning it over if the valves actually made contact with the Pistons. I think you’re gonna be OK.

 

Oops, I did get that mixed up. Taller lifters are definitely more potentially destructive than shorter ones. Hopefully it just held them off the seats without touching the piston. Only way to know is to fire it up with the right ones.

Now I didn't turn the engine, but when experimenting with parts from a 3rd gen Pentastar, I installed the exhaust rockers in all positions and went to turn the engine by hand and it barely moved before contact. The fulcrum of those rockers is higher than gen 1&2 rockers, which basically did the same thing but much further than your lifters would have. When I went to take them out I looked at the valves as they came up. Ones that were supposed to be shut had about 4-6mm of pre-load. I should have caught that on install (rushing in freezing cold), but thankfully I didn't skip the hand crank and caught it there. Had I actually used the starter, I would have wrecked everything.