Truck started rough idle vcs lights came on and check engine

Prior to: Slightly curbed rear passenger wheel, the car and tire tracks, VCSOFF and VSCTRAC came on and the truck beeped a few times. Still running fine. Came out for lunch and...

I went to start my truck and it started with a very rough idle. All the vcs lights came on, the car with tire tracks behind it again and then.... Check engine light flashing was flashing also.

Turned off. And waited 3-5 mins. Truck started fine. All lights still on.

It did the same thing two weeks ago. Each time starting truck cold it would run rough for a little bit then go back to normal. Codes said misfire cyl 6. Replaced coil pack and plug on 6. Reset codes. Ran fine till today. Same symptoms. It's late here so I will have to wait till tomorrow to run codes.

Any inputs? Tried gas cap.

 

How many miles?

 

2006 6 cyl, 4 l, 194k miles , offroad

 

Hmmm, how old is the battery?

 

Sticker says 8/16

 

Check engine light flashing is a major misfire causing catalytic damage. This can be caused by many things.

1: Scan the code, you're guessing otherwise. The traction light is only on as a safeguard against people removing the check engine bulb.

2: Inspect the spark plug, a new plug with a misfire can tell you a lot, also look inside the cylinder with a light if possible. You're looking for wet, burnt, broken etc.

3: Ok, lets assume its #6 again, the plug and coil are new and there's no reason to spend more time on them, next is to check compression.

4: Lets say compression is good or you don't have a gauge and feels fine with the thumb-over-the-plug-hole check. We need to check the fuel injector. I like to use a boroscope and cycle on the fuel pump to pressure the lines and see if it is leaking, you can also achieve this by lifting the rail out and priming the pump. You can also simply swap the fuel injectors with a known good.

5: If compression is good, the injector is good, coil is good and spark plug is good, it's time to bust out a voltmeter and an oscilloscope and you'd be better off taking it to a shop dependant on your level of skill.

 

how about swapping injectors between cylinder 6 and another cylinder assuming its throwing a cylinder 6 missfire code?

Also.... hate to say it but it might be the case of a 05-06 bad headgasket.

 

Didn't know that about the traction light, thanks!
Compression I think was 160 two weeks ago. I cant remember what it was but 160 comes to my head, it didn't make me question anything after. I will do it again probably since I don't think I wrote it down. Cylinder looked fine from what little bit I could see last time, with a flash light (besides having deposits as expected), no standing water, or and type of fluid. Just looked like dry carbon deposit. Will check everything when I start re-assessment. Which may end up being next weekend if it runs alright.

Will run codes tomorrow and come back. Going to order boroscope.... Literally needed one too many times to count for so many things and never had one.

Its weird to me that it only does this when first starting it after 4+ hours (from experience last time). We will see how it starts tomorrow.

 

I did think that at first, but I did the chemical test on radiator and it didn't turn at all. No bubbles in radiator and also not burning any coolant.

 

Started up this morning, no more lights, weird?

Started up several times fine/ ran fine.

Started up fine again for about the 4th time today with no lights on dash, went to autoparts store and ran codes about 5pm. Same as last time, it had P0306 cyl 6 misfire. Cleared the codes while I was up there

Ideas on what could be causing an intermittent problem like this?

 

Have you switched injectors?

 

No I am going to this weekend. I also ordered borescope to get better view of cyl.

 

Update: I am waiting another week before changing injectors/opening it up. still no issues.

 

Hmmm
Us electricians call this electrical flukes

 

This problem has been occurring to me once every two weeks maybe but I've been driving it a lot less. When I was commuting everyday with it, the problem happened maybe once per week. When it does happen and the check engine light is flashing the truck is definitely in some sort of limp mode with difficulty moving a few feet. I turn the truck off and wait a minute, restart and can do that once or twice and it starts fine not in this limp mode or running rough.

All the lights have previously gone away eventually without resetting anything, so In my mind this cannot be mechanical or it would be consistent. I've heard of o2 sensors causing some issues relatively similar but that's just a possibility. Truck has 199k miles now. Since last week's episode of this the lights have not gone away.

No noticeable amount of oil or coolant is burning so i do not think cyl 6 misfire code is related to a headgasket. Since this is so randomly intermittent I also wouldnt think of a headgasket.

Any thoughts?

 

Did you redo the leak down and compression test? I don't have much faith in the chemical test for a blown gasket.

I am leaning towards a blown head gasket also.

I noticed that you didn't comment about changing the injectors etc...

There is a possibility that it is a small leak and drips into the cylinder slowly when sitting and cooling.

There is also a possibility that it seals off when it warms up due to metal expansion with heat.

 

Did not redo compression test. I did not change injectors, I was reading another thread on doing them and others here said not to do it unless you had a pretty good idea it was them causing the issue. Do you think I should go ahead and do them? I do not think they have ever been changed.

Someone mentioned having 400k miles on stock injectors and not to touch them unless problem could be traced back to them.

 

This happened to my truck when it had 500 miles on it. Turns out my problem was the clip that plugs onto the coil was not on all the way from the factory. Sounds like you already checked there. Good luck!

 

So i just ran the codes and I got the P0306 for cyl 6 misfire and P0022 which another post on TW said P0022 DTC specifically refers to the camshaft (cam) timing. In this case, if the cam timing is over-retarded, the engine light will be illluminated and the code will be set. The "A" camshaft is either the intake, left, or front camshaft."

Im lost?

JimmyH,
on this thread here you wrote a reply to someone with this code. Do you think case this is something similar?