My truck is a 2005 F250 4x4 6.0L Auto, stock engine except Banks intake. I've owned it since new. Never had any issues. Now at 54,000 miles I can say for the first time I really am using it to its potential. I just bought a 13,000 GVWR Toy Hauler and took it down to Pismo this last weekend for the first time. Pulling the Questa Grade on the way home I was hearing some noises I've never heard before. I'm hoping you guys can clue me in to what they were.

First noise I did hear a few times on the way south to Pismo also. Heard it anytime I was pulling a moderately tough grade, came on after the motor had been working for a short period. IMO, it sounded like the engine fan coming on... sort of a moderate pitched roaring sound... not too loud, it could easily be missed, but I was listening for it... and consistent with that of a fan pushing air.

The 2nd noise I only heard when pulling the Questa Grade northbound, a much steeper grade. After the first noise (assuming engine fan) had been on for a short while, a much louder sound, a higher pitched roaring started. My best guess this was a secondary fan kicking in. True?

But next the 3rd noise replaced the 2nd noise and every couple seconds it would switch back and forth between the 2nd and 3rd noises, until toward the top of the hill it just stayed with the 3rd noise. 3rd noise was hardest to describe. I thought of it as a high pitched buzzing. I had no idea what it could have been.

The entire time the truck pulled strong. Engine and tranny temp showed normal... couldn't even tell if the needles ever moved. Boost (stock guage only) was constant at about 28 psi. Never got any warning lights. Not even any hot or unusual smells from the motor/tranny.

I know its a shot in the dark, but if you can decipher my strange noises and help me learn more about what the motor is doing I should would appreciate it!

Thanks,
Scott

 

The first two sounds are almost certainly the fan. That thing can get LOUD. It has a clutch system so it can turn at various speeds according to the truck's requirement. Living here in Vegas I get the fan kicking on quite often. I have a digital water temp gauge and my fan really starts roaring at about 215 degrees but it will kick on lower before that.

I am not sure about your 3rd sound though.

 

I concur...you're hearing the cooling fan. It's pretty amazing that these don't kick in more often...but they don't.

Joe

 

Definately sounds like the fan and with the driving you were doing it's a sure thing the fan kicked in. 3rd is not as easy, maybe it was the fan just after running so long it has stages it runs throught to provide cooling.

 

Definitely the fan. Loud, ain't it?

The Visconic fan on the 6.0 is electrically controlled by the PCM based on several variables input to the PCM by numerous sensors on the engine. It gets louder under greater load and cycles on and off as the PCM deems necessary.

The NB Cuesta Grade is a steep sunnavagun! I'll guess that the 3rd sound was just the fan really screaming due to the load on the engine. If the engine temp was OK then the fan did it's job.

 

And if the transmission downshifts while the fan is on the noise increases as the engine speed increases.

 

My fan did the same, now after I did the EGR blocker my engine runs much cooler (fan barely comes on), EGT's are much lower. My opinion the EGR has a lot to do with causing it to run hot and destroying your engine.

 

28 psi is a lot of boost to hold steady. You really should get it to shift down if its working that hard and don't crowd it too much. Putting it in Tow/Haul mode will help it hold a lower gear as well. Getting the RPMs up will lower your EGTs as well, which can get pretty hot on long grades.

 

Thanks all the replies. The RPMs were about 2,800 or so... I was just really interested to see how well it could pull it and if I could maintain any speed. I dropped to 48 MPH and held steady. The older Chevy truck also pulling an RV behind me was no where to be seen when I reached the top, so my truck must have been doing a fair job.

I'll probably be ording some guages in the near future to keep an eye on things

 

That was just that 6.0L saying thank you for taking me out to play finally! Wait till you hear the air scupping (sounds like a pig snorting) with decelerating with a heavy pull. I asked a lot of people about this but didn't ever get a straight answer. Enjoy your workhorse...just make sure to feed and water her and don't put her away wet.

 

the sound your taking about i think is the turbo. after it has a high pressure then you come off of decel it can puff at you. this only happens if you have a moderate amount of drag on the turbo vanes. they dont open quick enough to relieve the pressure so you hear it trying to escape from other orafaces in the intake. sometimes the EGR Valve.

and yes sounds like a fan to me too! thats a great fan. not to great of an engine but a good fan. they barely ever fail.

HangOn2me: again EGR does not contribute to engine over heating. look it up i dont want to explane it again. wikipedia

 

Wyatt-
I have watched several threads where you have treated people like they are idiots because they dont believe what you say about EGR and I am tired of it so I would like to try to politely set things straight.

Most folks on here understand what you are saying about EGR gasses during combustion and how they do not cause an engine to overheat.
It is the EGR COOLER in these engines that causes flash boiling or causes higher coolant temperatures. It is 1000* F and higher exhaust gases being cooled by ~200* F coolant that causes the problem. After cooling exhaust gasses in the cooler the coolant is going to be hotter - quite obviously making the engine temps higher.
In addition - if the EGR process is so great like you claim why aren't people adding them to non-egr engines to make them more efficient?

The EGR valve has its place and many of us choose to delete it from our engines to try to keep from having some of the problems inherent to the cooler and things.

If you have not ever removed the EGR and cooler from a 6.0 liter diesel and subsequently seen the coolant temps drop - as many on this site have - please try not to belittle folks who are just trying to get help.

Greg

 

Greg,
You and I are on the same page...Thank you for your support...

All I can say is Wyatt please keep you EGR working so you will/may experience catastrophic engine failure.

Wyatt I am not the only one here who does not think much of your comments and opinions. Please if you do not have anything good to say please do not comment...

This Forum has been really helpful from ASE mechanics directing myself and others with there experience and knowledge.

All my comments about the EGR is not made up B.S., first of all I have experienced my self first hand engine failure caused from the EGR system failing.

 

OK Gentlemen, enough.

You cannot mistake the engine fan engaging in this truck, it almost will scare you right out of the drivers seat. Swilson you have a few things going on by which you describe. I would have the temperature sensor checked if you say the reading was normal and the fan kicked on.

 

swilson,
My apologies for the thread hijack.