Took vehicle to dealer on 1/8/2015 and left it with them for two days during some very cold weather. They were unable to replicate the issue. I spoke with one of the mechanics and he said that he has never encountered a problem with the VTC actuator on the Civic si. However, he did state that he has seen this issue in the CRV and he also confirmed that the civic si has basically an identical engine. I was charged $70 for the rental car.

On 1/12/2015 at 7:06 am cst, 29 degrees outside, I started the car in my garage and heard the grinding noise again.

I have not hear word one from Honda or my "case" manager. Last I spoke with her I requested that she provide me information on the VTC actuator problem in the CRV. I want to know if this is causing damage to the engine.

This issue is occurring on cold starts after having left the vehicle sitting overnight. The problem only seems to be occurring on very cold days where the temperature is below freezing. When I start the engine it turns over and is then followed by a 1-2 second grinding noise that varies in severity. I have done lots of research online regarding this and the consensus seems to be that the problem is coming from the VTC actuator. Many have suggested that specifically the VTC actuator locking pin is not going into the fully retarded position which causes all of the oil to drain out of the chambers in the VTC. The problem is thoroughly discussed here:

http://www.9thgencivic.com/forum/general-maintenance/65761-cold-start-scraping-noise-2013-si.html

Some highlights:

"When the Lock pin is not at fully retarded position and locked, the VTC is going through the +15 and -15 degrees and this combined 30 degree of this cam phasing hits or bangs against the fins of the actuator and results in fatigued metal fins. When and if the fin deforms, then the effective cam phase angles variances becomes more than the Valve clearance at a given position of the piston relative to valve opening. This can lead to piston hitting the valve."

"What I think is going on is the oil is too thick in cold weather to get pumped into the VTC quickly enough to prevent the rattle. Additionally, a locking pin (meant to lock the VTC rotors when oil pressure is at zero) fails to lock, possibly because it is bent ... not really sure about this part.

The rattle comes from the four rotors inside the VTC whacking against their stops. (because there is not enough oil inside the VTC and/or the locking pin is not locked.)

The VTC has four chambers that can be filled with oil either on one side or the other side depending on which way the VTC Oil Control Valve is set. If there is oil inside the VTC chambers, there's no rattle since oil pressure holds the rotors into their correct position.

If the VTC rotors are whacking back and forth, this also means the camshaft and thus valves are also getting shifted back and forth rapidly.

When you park the car for a long time in cold weather the oil inside the VTC slowly oozes out and then it's "dry." (actually it probably still has a thin film of oil all over, but not enough to prevent rattling.)

Apparently this is also an issue with the Honda CRV and some earlier Accord models, which also have the same K series engine.

I am taking the car into my dealer today and hoping that they can replicate the issue. It is supposed to be really cold the next couple of day so I believe that the conditions will be right.