Engine Rapping When Cold

I've noticed that my new 2013 V6 has an engine rapping noise when I first accelerate with the engine cold, if it is around 45* or colder out. It sounds like the oil is low or something, but I checked and it isn't that. I'm not talking heavy acceleration either, just normal getting up to speed kind of thing. It's not super loud, but it is definitely there. Once I go a half mile or so the noise goes away.

The truck only has around 1700 miles, so maybe it is just not broken in yet? But I never had this noise on my 2010 V6 Tacoma. The only difference is I bought that one in May (2010), so the weather was warmer during the break in period.

I know if I take it to the dealer they won't be able to recreate it because it only happens when it is coldish out, and they won't look at it until later in the day most likely.

Anyone else having this issue?

 

I just bought a '13 PreRunner V6 last month and have noticed the same thing. I have done some searching on "the google" and believe it is coming from the air injection system. It was slightly redesigned on the '13 models. It is supposed to heat up the engine and catalytic converter more quickly and reduce emissions.

If anyone has any other ideas, I'd love to hear them, but this is what I found so far.

 

Thanks for the info. I guess I feel a little better that mine isn't the only one, so hopefully not a lemon. Anyone else experiencing this yet?

 

Sound more like a east coast, or west coast rap?

 

Air injection sounds like a vacuum cleaner when the truck is cold started and has a relatively short timeout (under 40 seconds after start on Tundras, I bet the Tacoma is the same).

My '09 does the rapping noise and I don't have air injection. Many speculate piston slap. Toyota using low-silicon pistons perhaps? The four cylinders do it too.

One reason I treat it like I did my Hondas. No throttle for at least 30 seconds after a cold start, only moderate load and under 2000 rpm for the first 5 minutes of driving, and no full throttle stuff until after the coolant temp has peaked (<185°F) for a couple minutes.

https://en.wikipedia.org/wiki/Hypereutectic_piston

 

Yeah, that's how I treat it as well. It did have 300 miles on it when I got it, so I wonder how they treated it on the way from Maine to NH where I ordered it.

 

beat me to it

 

If by rapping you mean making a "psssssssssshttt" noise, then I think my does that too. I haven't paid attention to when it actually does it but the first time I heard it I had to pop the hood and made sure it didnt get blessed with boost.

 

No, it's more of a dry hollow "clunk clunk clunk clunk" noise.

I do a weird pssshhht noise when it shuts off though. I did see someone here explain that one though, so I'm ok with that one.

 

Piston slap.
Normal.
My '03 4.7 Tundra sounded like a Powerstroke when the temps were below 50.

 

could it be that sensor thing on the drivers side of the intake?

http://www.tacomaworld.com/forum/2nd-gen-tacomas/43632-ticking-engine-one-fix.html

 

The valve could be contributing to it, but piston slap is extremely common on newer technology engines.

 

got ya.

OP, might be worth it to unscrew that sensor, and zip tie it away from anything and go for a ride. aparently that sensor amplifies the noise. havent done it, but i dont have the clicking noise either...

 

Mine raps like a mofo when it's cold. Once the motor warms up it's all good.

 

try that sensor relocate mod.

 

Thanks for the info, but it's not the ticking noise either. I did have that ticking on my '10 Tacoma. It never bothered me much, but this is more of a rapping than a ticking, so it's louder and more troublesome sounding. Maybe I'll try to get a recording of it.

The piston slap theory sounds more reasonable for this noise. Of course, it also sounds like something a quality new vehicle shouldn't have as well.

 

take it to the dealer, and ask them to hear yours, then ask them to drive another one and see the difference

 

X2. Defiantly not the tick. Mine sounds like yours OP, like its low on oil. It's always done this since new.

 

i have a 2013 dbcb trd sport and mine started doing this also when the temp. dropped. Toyota Tech. is my neighbor he is going to come over in the morning and listen to the noise. Hopefully I can get us some answers!!!

 

It could be the airbox rattling against the hole in the chassis in the engine bay.

Sounds kinda like a rumble or a hollow vibration like you described. Goes away after the engine is warmed up. Mine does the same thing, I've never gotten around to fixing it. Some guys just add some rubber or foam around the hole.