Oh no! Rattling under the valve cover - solved!

[cfmustang]

The last few days, we have been having really unseasonably warm weather here for this time of year. So, yesterday the wife and I take the Mustang to a friends house. I figured it was so nice, it would be good to get it out one last time before being put away for the winter.

The ride there was uneventful, but when I was driving home I started hearing a rattling I have never heard before. It didn't go away when I put it in neutral and it seemed to stay about the same regardless of rpm. It almost sounded like something in the fan. Well, I got home quick and popped the hood...nothing in the fan. Also, it sounds like something under the valve cover (I hope its just that and not in a cylinder).

I didn't have time to pull the valve cover last night, but the weather is still decent so I will take it off when I get home from work today...I have a bad feeling about this...

 

[ludwig]

Use a long screwdriver touching the valve cover and press you ear to the handle. Move it along the valve cover and find where it is loudest to localize the problem. If it is under the valve cover, it may just be a loose rocker arm. Of course it may be something more serious, but if it stays the same, regardless of RPM, it would be a motor or something close to the engine: wiper motor or heater motor not turned all the way off. Or maybe you have an electric fuel pump. I don't know.

 

[cfmustang]

I forgot about that trick. I might give it a try, but I am a little wary of running the engine without knowing what it is.

It certainly sounded like a loose nut or something in there. The fuel pump is a stock mechanical. Wiper motor is off, but I can double-check. I also though it may be the blower motor, but that is not working at all at the moment.

What is weird is that didn't seem to be any change in the performance, so I am thinking (well, hoping) that I didn't drop a valve.

 

[cfmustang]

Whew! False alarm.

I pulled the cheap-o chrome valve cover I have had on the car for the last 10 years and the spot welds holding the oil baffle underneith the PCV valve had completely let go. The baffle was laying across the rocker arm assembly. That is why it sounded so bad!

Oh well, this just gives me a reason to clean up that Powered By Ford valve cover and have it Jett-Hott coated.

By the way, are the symptoms of a oil clogged PCV valve stalling at off idle? I needed to get the tank topped off and add some fuel additive before putting the car away for the Winter and that is what started happening about half way to the gas station.