If my Timing Chain slipped?

[07 Boss]

If my timing chain slipped a tooth or two wouldn’t it throw a code?

 

[Iceman62]

I'd guess you'll see/hear something, but what makes you think she jumped?

 

[FredB66]

Mine jumped and it did not throw a code. Aside from the no-start, there were no other symptoms. The only way I could tell was to pull the valve covers and check. I was very fortunate to not have a p-v crash so if yours jumped I hope you're as lucky.

 

[07 Boss]

Figured it out. She was stumbling and missing and down on power. Seemed to start and idle OK but as soon as you started to drive she would start stumbling and missing and smooth out as the load decreased. Anyways it ended up being a bad plug, weird but it has happened before and I will start a new thread since it has nothing to do with the timing.

 

[GlassTop09]

It kinda will depend on how far 1 bank goes out of phase timing-wise in degrees from the other bank before a DTC is lit.

Don't forget these 3V's VCT in OEM design (meaning no cam phaser limiters\lockouts are installed in cam phasers & load% maps in tune aren't changed from the OEM VCT max operational retard of 55*) can retard cams a max of 60 crank degrees (30 cam degrees) from 0* w\o incurring piston to valve interference so if a chain on 1 bank jumps only 1-2 teeth on 1 gear only it is theoretically possible that the PCM won't see it as far enough out of phase cam timing wise to flag it BUT you should definately feel this (engine shake) due to the engine being out of balance from imbalanced dynamic compression (1 bank having higher compression than the other) when rotating. The PCM checks VCT for this on every startup (checks actual cam retard vs commanded retard as well as cam to crank signal sync) so if this is passing then usually no DTC is lit.

To determine if this is your issue you can either do a relative compression test to see if all the low peaks are all on 1 bank relative to the other thru the firing order or if you have a scan tool that can show these 2 PIDs.......VCT adverror, VCT adverror2 (these are the 2 bank's cam timing signal error vs crank timing signal) you can see which side is showing to be in a larger degree error state which will point you to that side having this potential issue (most of the time this indicates a stretched chain, a blown out chain tensioner or a stuck VCT solenoid but also a jumped chain if only 1 or 2 tooth jump). PS--Just now realized that this can also be noted thru Mode 6 Misfire monitor showing far more misfires on all cylinders of 1 bank vs the other bank's cylinders since the CKP sensor will be picking up the variations......

This cam phasing is a normal function when using hydraulic pressure to maintain chain tension during rotation meaning the cams will walk a little out of phase usually when changing rotational speeds but will recover very quick so there is a threshold point where the PCM will call a cam timing DTC.

This is why 3V's don't use a ratcheting type of tensioner as the 2V's did......3V's use VCT thus a spring loaded tensioner to allow the cams to move slightly out of phase during VCT operations w\o over tensioning the chains & to maintain chain tension while engine is shut down (no oil pressure).

Hope this helps.