It's in the single digits today and fired up the CS to go to a friends house.

Noticed that it ticks at idle, under acceleration and normal cruise until it gets warm. I am running Mobil 1 5W20.


Anyone else notice this?

 

I believe it sounds like the injectors. A few people have noticed it over on s197forums.com too. Some say its normal and others say differently. I have a little at cold start up but goes away after it idles down. I'm running Motorcraft Full Synthetic.

 

I've heard the injectors. It doesn't sound like that.

This sounds like a lifter(s) in a pushrod motor until the engine gets to normal op temp. It's louder than a tick and less than a clunk.

I wonder if it has something to do with the oil. I thought that someone posted that M1 Syn is a bit thinner than the MC semi syn 5w20 until it warms up. Dunno.

 

Why would injectors matter?

All valves clack briefly - the 3V has a nice muffled clatter even when warm and with hydraulics. But I'm surprised both comments are from full synth users. Cold lubrication is supposed to be their thing, right?

 

Maybe mine is more or less just valve train noise

My Intrepid was a DOHC and made similar sounds. I can only really hear it when I am standing in front of the car.

 

Yeah, and that's what I thought too. Never had an issue before now. And I've run full syn M1 in many cars in the past. But not one like the 3V 4.6.

My very limited understanding of syn oils is the level of the base stock (LIII +) and their flow at cold temperature is better than conventional oils. Maybe it flows too well at cold temps for this motor?? I have no idea if that is even possible.

Could be that the tolerances are large when cold and the oil flows enough to lubricate but it takes a while to heat up the metal and close the tolerances up. This is WAY above my understanding. These are the coldest temps I have driven this car, FWIW.

After the motor gets to full op temp, it is fine. No noise. I'm not really concerned but it seemed strange so I thought I'd ask if it is common. If it is abnormal, then it might be an issue.

 

I can't say I hear anything with my car and I was out yesterday in the 7 degree weather, but maybe with my exhaust and the SC it gets drowned out. I have 5w30 in. Maybe it's a small exhaust leak from being so cold and everything contracting and it goes away when gets hot and expands.

 

It was about 12 degress warmer today and the noise was not heard.

Writing off as fluke.

 

Heh another Illinoisian, 12 degrees warmer, to a whole 17-18 lol

 

Well its good to know i'm not in the process of blowing my motor.

 

I doubt that.

It could have been the cam phasers, or whatever they are called. The most frustrating thing with this engine is how little I know about all of these tweeks that make them run so well.

It seems better to ignore these types of things unless it sounds like the motor is going to tear itself apart. And I know what that sounds like:

 

It's happened to me as well on my '07 GT. Sounds almost like, I don't know... like a rattling noise, somewhere in the engine bay. If I accelerate, uh, rapidly out of cold start, it does it. I'm running Mobil 1 full synthetic, so...

 

Hmmm. There seems to be a common thread here. In my case, it goes away when the car warms up.

 

I have a similar ticking noise under acceleration only it doesnt ever go away, sounds like its coming through the ac vents or gauges almost. It just started like a month or so ago out of nowhere

 

Found a couple possible answers to the issue on another forum. A few highlights:

"I have an '06 that does the same thing. It is definately piston slap (not VCT phaser). Does it once the temperature gets below ~50F. When I first start the engine, it will rev-up for about a minute then settle down to a lower idle. During this period, the piston slap is faint and takes effort to hear it over the fan. But if I put it into gear without warm-up it is very pronounced and gets worse if I accelerate with it cold. Once I reach about the quarter mark on the coolant gauge, it is practically gone (~3 minutes). It is completely gone once the engine is warmed up. I have compared the Ford piston to cylinder clearance specs for the 5.4l engine with engines before 2004 and found that they there was a small increase in clearance for 2004 and later engines.

From all that I have read, no oil will get rid of piston slap. The only solution I have found for cold weather starts is to just start it up and let it run for about 3-4 minutes (warm-up the engine), then drive. On my truck, the piston slap is completely gone if I do this.

The piston slap sounds sort of like a mild diesel when in gear in the garage and more like a lifter (from inside the cab) when accelerating but only if I don't let it warm up on the first start of the day during very cold weather. Otherwise, the engine is as quiet as a mouse.
BTW, the differene between piston slap and VCT phaser diesel-like knocking sound is that piston slap occurs only when the engine is cold soaked and goes away when warmed up. VCT phaser sound doesn't occur when the engine is cold, but begins when the engine is warmed up."

Another opinion: "Piston slap is only a "defect" in that it annoys the driver (some drivers). It doesn't harm anything mechanically. It was commonplace 60 years ago, and then automakers got clearances tighter, went to autothermic pistons, and so on. It came BACK when automakers started doing things to boost efficiency- using short-skirt hypereutectic pistons and eliminating the wrist-pin offset that was only there to hide piston slap in the first place, but increased friction! The final solution was to add skirt coatings to (once again) hide the noise, but not add nearly as much friction as offset wrist pins."

Another possibility: "Our 03 4.6L doesn't have piston slap that I can tell, it runs fantastic on MC Semisyn 5W-20. IMO, Piston slap won't hurt anything. The problem comes from the fact that over the past decade auto mfr have used short skirt pistons (Very short pistons from crown to the bottom) and when cold, they can move around a little bit making some noise. (This is what my understanding of it is anyway) until the engine has warmed up and the piston expands to fill the gap."


All three of these sound plausible. Maybe some of the engine gurus will chime in and confirm or deny.

 

You know, I may be way off base here, but the experience I have with piston slap is on 2 stroke dirt bikes. You didn't hear the rattle at idle and medium rpm - it was windin' out at high rpm's that you heard piston slap - and that was on an engine with some wear on it.

Those explanations are interesting but I'd need more confirmation.

 

Yep, that's exactly it.

I'm not sure if piston slap is what this is. I hear it at low to medium RPM, during average to heavy acceleration. I've also heard it idling, but only one one occasion. It almost sounds like it's... sorta under my car, like... just beyond the radio in the engine bay, you know what I mean?

 

That's it on mine too.

It might be an inherent thing.

It'd be nice to know if it is.

 

I get the same thing on my 2008 GT as well. Car runs fine so i'm guessing its nothign really. Only notice it on colder days.

 

That almost sounds like where the gearbox is... is it the syncrho's or tranny gears rattling in the thick fluid?