2014 Mystic Green with Misterious Issues

[IPF Racing]

Hey everyone, picked up my first Caprice last week, a 2014 9C1 in mystic Green with a couple issues. I've tried a bunch of stuff to fix it but hoping you all can help me out.

It has a CEL for misfire on cylinder one and it is also blowing oil smoke out of the exhaust, mostly on the driver's side.

This lead me to the normal checks, swapping coils and plugs and wires, tried swapping injectors around, traced wire continuity back to the ECU. No matter what I do the code is always on cyl 1. I also replaced valve seals on cylinder one thinking that maybe oil was the issue. The plug does come out with oil on it which is odd. I routed that side of the pcv to the catch can to see if it would help clear it up but the intake manifold has a decent amount of oil in it.

I also did a compression check on that bank; cyl 1 was 180psi and 3 and 5 were both 170psi. Leak down test on cyl 1 was also good at 2%.

It doesn't make any clattering noises just idles rough and smokes on load. 10k miles ago this car had a new cam, valves, lifters, head gaskets, and all seals replaced just for reference.

Let me know what y'all think, I'm open to just about anything!

[Sanford]

Perform a running compression test on that cylinder on #1 cylinder and see what you come up with when compared to #3. The 2nd Caprice that I picked up had a misfire on #4 cylinder. It was quiet but it had a misfire on that cylinder and smoked like heck out of the passenger side exhaust. I did a running compression test and #4 obviously had a problem although the cranking compression was acceptable. I ended up pulling the valve cover off of the passenger side to watch the valves while cranking. The valves moved as they should while cranking, but as soon as the engine fired up, the intake valve quit moving.

It turned out that the cam had lobe damage. I swapped another DOD cam and lifters into the engine and all has been well. It did do some serious smoking out of the right side until all of the oil got burnt out of the exhaust system.

Don't know how often VLOM's fail, but since the cam and lifters were replaced, you may have a VLOM that has a solenoid that is leaking oil through it and it is disengaging a lifter on #1 cylinder.

David C.

[IPF Racing]

That's good insight! Can you educate me on the VLOM? I'm not familiar with what that is or how to check it's functionality. I'll perform a running compression check and rocker movement next time I'm at my shop.

[s/c'd cav]

welcome to the 1 of 15 club , ive also got a 14 mystic green

[Sanford]

Here is fairly recent video giving a pretty good description of how the GM DOD/AFM works.

https://www.youtube.com/watch?v=mkly7XmMsOs

[IPF Racing]

welcome to the 1 of 15 club , ive also got a 14 mystic green

Thanks!

Here is fairly recent video giving a pretty good description of how the GM DOD/AFM works.

https://www.youtube.com/watch?v=mkly7XmMsOs

Thank you! I'm gonna test it again tomorrow And see what happens. I'll report back tomorrow evening!

[IPF Racing]

Perform a running compression test on that cylinder on #1 cylinder and see what you come up with when compared to #3. The 2nd Caprice that I picked up had a misfire on #4 cylinder. It was quiet but it had a misfire on that cylinder and smoked like heck out of the passenger side exhaust. I did a running compression test and #4 obviously had a problem although the cranking compression was acceptable. I ended up pulling the valve cover off of the passenger side to watch the valves while cranking. The valves moved as they should while cranking, but as soon as the engine fired up, the intake valve quit moving.

It turned out that the cam had lobe damage. I swapped another DOD cam and lifters into the engine and all has been well. It did do some serious smoking out of the right side until all of the oil got burnt out of the exhaust system.

Don't know how often VLOM's fail, but since the cam and lifters were replaced, you may have a VLOM that has a solenoid that is leaking oil through it and it is disengaging a lifter on #1 cylinder.

David C.

Holy crap I may just love you, I certainly owe you a beer! Cranking compression was 180psi while running compression was 60psi. Pulled the valve covers and ran it, intake valve on cylinder one didn't even move. Took off that rocker and rotated that crank by hand to make sure the cam was moving the lifter and push rod. Sure enough they moved. Pulled the intake and valley cover after ordering another one, $159 on rock Auto. Should have it all back together Friday night when the parts get here!

There are some scratches on that cam lobe but I can barely feel them with my finger nails so I'm gonna run it. If it turns out to be a lifter or cam, I'll go after the DOD swap next.

I did confirm they reused the VLOM when they replaced the cam and valves previously so hopefully this solves the problem.

[Sanford]

Hope the VLOM will solve your problem.

David

[IPF Racing]

So it turned out to be a collapsed lifter that was spinning in the guide. 2 late nights replacing the cam and lifter and shes been running like a top! Love this thing! Putting a hitch on this weekend and then maybe looking into a rear view camera from a 2015...

[Sanford]

Any pictures of the carnage? Did you go back with the stock cam?

David