Loud "Dive Bomber" Whine - Diesel Forum

Bambi_Bandit · 03-28-2006, 06:05 PM

OK, I took my 2005 PSD excursion 4x4 for it's first cross country trip with my 28' Airstream trailer. This trailer is exactly why I have my PSD excursion. My trailer is ~7500 lbs. Coming from Austin TX to Orange County CA, the trip thru New mexico and Arizona was fine. I had the cuise set for 55-60 MPH, with the tourque-shift tranny set in tow haul mode the whole time. However, when crossing the mountains in Southern California, the tranny dropped down a gear and went to ~2300-2500 RPMs to comensate for the uphill grade and speed. A few minutes later, what I can only describe as a World War 2 dive bomber whine came from my engine. I immediatly looked at my temps (all normal) and shut the cruise off. Once the cruse was off, the whine went away, but as soon as I hit the accelerator, the whine was back, so it was tied to my RPMs somehow.

Now I assume that this is something to do with my turbo? I have no clue as this is my first diesel truck, let alone with any turbo.

So, for the rest of the accent up the mountain, I kept a low RPM (~1500-2000) to minimize the "dive bomber" whine, which resulted in a climb at 35-40 MPH...

Was this normal? Keep in mind I have no boost or EGT or any other guages to monitor other than the tranny, oil, and engine temp that is part of the orginal Ford instument cluster.

The truck seems fine now... so I think the turbo still works, but I don't know if I did a mistake or if it was normal and I just need to put up with that loud whine when I climb with my trailer.

Thanks for any input or suggestions,

Kevin

fordmastertech · 03-28-2006, 06:58 PM

I would be more apt to say it's your engine cooling fan not the turbo.
FMT

william_04_X · 03-28-2006, 08:03 PM

like FMT said... it's the cooling fan kicking on/off... i pull my 10K# trailer over those same hills between Baker and Barstow 6 or 8 times a year... in the summer it's 110 outside and i'm going 65-70...2 years no problems...

Bambi_Bandit · 03-28-2006, 08:56 PM

[ QUOTE ]
I would be more apt to say it's your engine cooling fan not the turbo.
FMT

[/ QUOTE ]

FMT / William_04,

If it is the fan, is it supposed to sound like a "whine" that seems to be tied to the RPMs?

Kevin

william_04_X · 03-28-2006, 11:01 PM

i know that it's a loud, scary noise the first time you hear it... i thought my tranny was slipping to oblivion when i first heard it..it does seem to intensify when you accelerate.. you're adding fuel with your right foot, generating more heat in the motor and trans, and that fan is trying to keep things in check..F.Y.I. when i climb those grades i like the RPMs to be 2300-2500..the low rpm's uphill seem to lug the motor..when i had my pyro on i would notice lower EGT's at the higher rpms(more air flowing through to keep temps down) and the truck performed better...there is no reason for a normal 6.0 to go 35 mph up a 6% or 8% grade with a 7500# trailer, unless you want to...

pabrannan · 03-29-2006, 08:21 AM

When I was out west my sweet spot for crusin was about 2200 rpms(72 mph), and on the longer inclines the fan would come on and make a heck of a roar for several seconds then all was fine until the next time. It seemed to come on slow reach its peak then go back to normal. Normally I cruise at about 68 MPH towing(2000 RPM). Sounds normal from here......

Paul B

Mudraga · 03-29-2006, 09:15 AM

I haven't looked and don't have my Excursion near by so I can check. Is the fan a normal clutch style fan? If not, what causes it to react to temperature changes? The reason I ask, is that I was thinking of making the 203 degree thermostat change. But this will obviously allow hotter air to the fan or whatever sensors make it lock up. I'm not sure the more efficient engine would be a welcome trade off if the fan was noisy all the time. [img]/ubbthreads/images/graemlins/confused.gif[/img]

Bambi_Bandit · 03-29-2006, 10:36 AM

Thanks for your thoughts guys!! So you all think it's the cooling fan. Is the cooling fan supposed to only come on in "extreme" conditions? I never heard it in the 100+ deg weather in texas when pulling on flat land.
It seemed to be tied to the engine RPMs, where it seemed lounder at a higher RPM than at a lower one, but completely go away with the foot off the accelerator, only to return when I touched the gas...

How do I know I wasn't cooking the turbo up those grades? I dont't have any guages, and as you know, the factory instrument cluster doesn't even have a boost needle like the superduty pickups...

Is there a way to tell the turbo is still safe by sound or a target speed/RPM in that extreme condition?

Thanks

Kevin

pabrannan · 03-29-2006, 08:38 PM

[ QUOTE ]
Thanks for your thoughts guys!! So you all think it's the cooling fan. Is the cooling fan supposed to only come on in "extreme" conditions? I never heard it in the 100+ deg weather in texas when pulling on flat land.
It seemed to be tied to the engine RPMs, where it seemed lounder at a higher RPM than at a lower one, but completely go away with the foot off the accelerator, only to return when I touched the gas...

How do I know I wasn't cooking the turbo up those grades? I dont't have any guages, and as you know, the factory instrument cluster doesn't even have a boost needle like the superduty pickups...

Is there a way to tell the turbo is still safe by sound or a target speed/RPM in that extreme condition?

Thanks

Kevin

[/ QUOTE ]

You don't have to worry about cooking the turbo, it's the pistons you have to worry about. Turbo made out of steel, pistons out of aluminum.
I'd get a set of aftermarket gauges so you know what is going on. You don't want to see over 1250* PRE-TURBO. If I were you I'd drop down into at least 3rd and keep the rpms up when going up grades. Don't sweat about slowing down, you don't have to be the first to the top!!!

Paul B

On edit you might re-post in the 7.3 PSD Engine and drive train, you will probably get more lookers and hopefully more answers.