Rattle noise from engine (Special Service Message 46173)

[Art Vandelay]

Hi, Today I took my car to the dealership to see about a rattle noise coming from the engine. I described the problem to them like this:

"A rattling noise while accelerating slowly between 2500-3000 RPM"

They got back to me with Special Service Message 46173 that says:

"Some 2016-2017 Mustang GT350 equipped with the 5.2L engine may exhibit a rattle or rapping type sound during cold operation at light loads and speeds from Idle-3000 RPM. The noise will be most noticeable during light acceleration in the 1500-3000 RPM range and may also be noticeable in the 800-1200 RPM range with neutral throttle blips. This sound is caused by the piston motion in the cylinder bore. This is an inherent characteristic of the forged aluminum pistons utilized in this high performance engine. Once the engine reaches operating temperature the noise will diminish, although it may still be noticeable even when fully warm. There are no durability concerns with this sound."


That sounds very much like my description of the problem.

So I guess most of you are experiencing this rattle and just dealing with it? Thoughts?

 

[Coosawjack]

Forged piston slap before they warm up.....Chevy had a lot of this way back......never a big problem as I remember!!

You are on record with the dealer now so go drive it like you want to.....if it pops dealer should cover ya!!

 

[Voltwings]

They have to account for expansion as things heat up. If the pistons fit perfectly when cold lol... you'd have a bad time when things warmed up and expanded.

 

[Art Vandelay]

I’ve driven many cars with pistons and they didn’t rattle.

 

[Drewsky65]

its common with forged internals. I have none in mine at all. but I wouldn't be too concerned unless the noise gets loader and more apparent in time.

I DO have this in my built 331 stroker in my 65 fastback

 

[Art Vandelay]

I’m not really concerned about it failing, it’s just that the noise is annoying and makes the car feel cheap. (A smooth engine sound would feel so much better)

 

[Drewsky65]

I’m not really concerned about it failing, it’s just that the noise is annoying and makes the car feel cheap. (A smooth engine sound would feel so much better)

Agreed, I’ve never heard of this in all my research on these cars. I wonder if this will develop in mine.

 

[CobraBob]

Your frustration is fully understandable. The GT-350 is a special Mustang and you should expect the engine to sound like it belongs in a special model. As stated, you're in the dealer's base now, so if it gets worse, take it right back for another check.

 

[tomshep]

The 95R also had this issue and a bulletin for it.

Tom

 

[Tob]

They have to account for expansion as things heat up. If the pistons fit perfectly when cold lol... you'd have a bad time when things warmed up and expanded.

This.

 

[Zemedici]

As stated, is a characteristic of the vehicle until warmed up

 

[Art Vandelay]

I get it, but seems it doesn’t affect everyone so that what bothers me. I’d prefer one of the non-rattling motors.

Anyway, I’ll just accept it for now...

 

[Coosawjack]

Turn up the stereo and CRUISE!!

 

[Need 04 Wine]

Got remote start? If so let her warm up for 15 before ya go near it.

Sucks big time would drive me flipping crazy


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[JAJ]

Got remote start? If so let her warm up for 15 before ya go near it.

Sucks big time would drive me flipping crazy


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Two reasons this won't work - first, manual trans cars can't have remote start, and second, if your engine does this, idling for 15 minutes doesn't get the engine warm enough to make it stop.

 

[Need 04 Wine]

Two reasons this won't work - first, manual trans cars can't have remote start, and second, if your engine does this, idling for 15 minutes doesn't get the engine warm enough to make it stop.

I would get aftermarket one then. Always someone who will install it.


If 15 minutes doesn’t stop it. Burn it down.


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[ArkLightning]

Many, many cars exhibit piston slap. In addition to forged piston clearances, the trend to short piston skirts and ring placement have also contributed. If it really bothers you and your climate is not real cold, you might consider stepping up to a slightly thicker oil - say a 15W-50 which might lessen it some. Good thing you weren't around in the performancee days of clacking solid lifters, pinging headers, and lumpy idles.

 

[Papaw]

You could always switch to cast pistons. They're quiet, but I wouldn't recommend it.