Alright, here's the rub.
2005 Ford CVPI with an interesting noise upon startup. This issue is most prominent on a cold engine, and seems to be worsened by cold weather. (It was warm when I got the car, and the issue began when the weather went cold).
- Upon starting the engine, I hear a metallic screeching sort of noise. Like a mix between a belt squeak and over-crank (Holding the key to start for too long, or trying to start an already running engine). This noise sometimes ends after a few seconds, but usually persists into the drive for an undetermined amount of time. Eventually the noise stops altogether, and does not return unless I shut the motor down again and restart it. By that time, if the engine is warm, it might not come back at all. But, say, leaving work at the end of the day... it's happens 95% of the time on startup.
- I have already considered the usual suspects... and have replaced the belt, idler pulley, and the tensioner assembly. This made absolutely no difference. I hand-spun the pulleys to no avail, and I have just started the car with no belt on it at all. The noise is still there.
- The engine runs flawlessly, and I mean that. For having a hair over 180,000 miles on it, it does not smoke or burn any oil. Other than a minor exhaust leak at the passenger side header due to a rusted nut shearing off, it even sounds good.
- If it rains, and I drive the car around... or if I power wash the underside of the car (Dirt and grime builds up down there you know!), sometimes when I go to start the car, the starter will just spin hopelessly, the bendix not extending and meeting the ring gear to turn the engine over. Once I left off the key, and the starter begins to spin down, at the last second it will 'catch' and grind against the ring gear for a split second. Low and behold, this noise is exactly the same noise I hear when I start the car. Exactly...
- Sometimes when the noise ceases to exist, I'll hear a momentary increase in volume from the noise and then it goes completely silent. Almost a bang.
- If you ask me, it sounds like my starter is sticking. Starting the engine, but not coming off the ring gear properly and knicking the gear.
I have already been approached with the idea that it's the timing chain guides, but I have looked up said issue on youtube and it isn't the same. Also, the noise does not come from the front of the engine. It seems to come from the passenger side rear, down towards the transmission. Another hint, possibly?
I have also been told it could be a heat shield. This is logical, because it sort of sounds like a heat shield tightly scraping against another metal surface at a high frequency... further inspection revealed no such heat shields to begin with.
Allow me to reiterate: Once the noise has gone, it is gone completely. It will not return for the duration of a drive, unless I stop the engine and it decides to do it again upon startup. It is RARE that the noise occurs once the engine is fully warmed up.
- The Doctor
2005 Ford Police Interceptor
- Former Windsor County, VT cruiser