Hey guys, ever since I bought this truck back in October it makes this noise on the cold start. It goes away after a minute or less of idling but I still haven't been able to track it down. When it got below freezing I was able to see exhaust coming out of that area so my first thought was the boot off the turbo might be ripped but from what I can feel it seems to be intact. I'll try to confirm that, but are there any other places I should be looking? The odd thing is that after a minute or so the noise goes away and I don't hear it until the next morning.


The truck is a 2011 F-350 King Ranch, it did this bone stock and it is currently DPF deleted and it's still doing this. EGR is in place but un plugged.

 

Mine always made that sound, it's just there to annoy the neighbors.

 

Sounds to me like the turbo bearings.

 

Can't tell if it's a bearing whine like Scott mentioned or if it has something to do with the glow plugs or modules when it's cold..

 

My first concern is the turbo, however if the bearings were bad why does the noise go away after a minute or so? Is there an easy way to check these turbos?

 

My bet would be the exhaust manifold(s).

 

Mine makes EXACTLY the same sound when first started. It goes away in a few minutes and doesn't come back for the rest of day. It's done that for a couple years now. I just ignore it.

Rob

 

Today's a good weather day so I'm cleaning the intake and going through that. I have the throttle body off and I'm getting ready to put it back on, however I can't seem to find the harness to plug it in? I didn't take one off either which has me worried however there was nothing I yanked out. Where can I find the harness in the engine bay? I can't seem to find it anywhere.


EDIT:
Is that one of the plugs that get unplugged for the EGR?

 

Hard to tell on audio recordings. Mine sounds like a mini table saw (not constant) when it's cold, sometimes. I've not been able to capture the exact sound with a phone mic. It has done this for eight years. It's only at idle. If the temps are below freezing and I turn on high idle, the sound doesn't occur while it's producing 5 PSI boost for warm up (or at least I can't hear it). When the warm up strategy is done after 2-3 minutes and boost returns to 0, the noise doesn't occur. I have not had the noise occur yet this winter but I also don't think I've been driving it on those cold days.

 

Well I cleaned the intake and got everything back together, that wasn't the issue. I have a SCT GTX tuner / monitor so I was curious to know what the VGT % was doing when it makes this owl noise but the VGT % stays constant. If I raise the RPM ever so slightly it goes away. I'm also noticing on the warmer days the sound is a lot quieter and doesn't last as long. After cleaning the intake I noticed there's little holes in that plastic tube that people say breaks a lot, I wander if the sound is air getting through there.



And the intake needed to be cleaned BADLY

 

What is that?

Rob

 

That pic specifically is right behind the throttle plate, in the engine it is right here:

 

I also replaced the intake tube, as a precaution. All I saw as a bit of oil film. You seem to have a lot of carbon buildup.

Rob

 

That is nasty looking!

 

Wow! And I wasn't sure what to think about mine when I noticed it while replacing the CAC pipe.