Ford V10 whistler

[Zeema12]

Does anyone have any ideas or experience with this problem:
I have an '03 Infinity on Ford chassis with the 6.8 V10 with about 7,000 miles, towing a 3,500 lb. car. The whisteling problem started around 4,000 mi. and happens when climbing a steep grade (5-7% grades)and the tranny has shifted down to 2nd (or even 1st) with RPM over 4,000 (it usually takes about 1/2 mi. or so before noise begins). The sound is very shrill (like a referee's whistle) and drowns out the normal engine noise (which is a good roar at these RPM's); noise pitch will increase/decrease with RPM changes but not go away until tranny is able to upshift to 3rd or 4th on downhill or level road. Engine gages and lights are all normal when this occurs; no misfiring/stalling. I suspected intake or exhaust airflow causes and had local Ford dealer check, but the problem does not occur on level ground or mild grades so they could not duplicate and did nothing. from Mike

[Zeema12]

Does anyone have any ideas or experience with this problem:
I have an '03 Infinity on Ford chassis with the 6.8 V10 with about 7,000 miles, towing a 3,500 lb. car. The whisteling problem started around 4,000 mi. and happens when climbing a steep grade (5-7% grades)and the tranny has shifted down to 2nd (or even 1st) with RPM over 4,000 (it usually takes about 1/2 mi. or so before noise begins). The sound is very shrill (like a referee's whistle) and drowns out the normal engine noise (which is a good roar at these RPM's); noise pitch will increase/decrease with RPM changes but not go away until tranny is able to upshift to 3rd or 4th on downhill or level road. Engine gages and lights are all normal when this occurs; no misfiring/stalling. I suspected intake or exhaust airflow causes and had local Ford dealer check, but the problem does not occur on level ground or mild grades so they could not duplicate and did nothing. from Mike

[JoeH]

I had a problem with the idler pulley-- it would really howl above 3000 rpm--- below that it was fine . Had it replaced under warranty -- all has been fine since

[Joe-K]

I've also got a hunch it may be related to the fan belt slipping. SInce you indicated it typically takes a half mile or so of low gear/high RPM running on a hill to make the sound start, I'm guessing the sound is due to the increased drag on the drive belt with the thermostatic fan engages.

As heat builds up in the engine due to the steep grade, and high RPM's, the engine temperature increases. Once the fan sensor gets warm enough, it locks up the fan clutch pulling much more air through the radiator. Perhaps this happens and your hearing some fan belt slippage combined with more fan noise.

[pleeds]

Zeema12:

I have the same experience with my '03 Itasca Suncruiser on the V-10 chassis. I've talked to a Ford rep. and he says Ford has no explanation. I thought for a while that it might be a warning of over-revving but the Ford guy said there is no built in warning. He did say not to exceed 5250 rpm because that engine will start shutting down cylinders. I even had a suggestion from the other board that the whistle was caused by the thin piece of aluminum between the transmission and housing setting up a harmonic as it vibrated. (He may have been pulling my chain.)

Anyway, I've learned to live with it. If you find an answer I'm sure a lot of Ford V-10 owners would appreciate hearing about it.

[Zeema12]

Thanks for responses and advice. I'm going to have the idler pulley and belts checked - never considered this because of the very limited times during which this happens. I'll keep you posted.

[DriVer]

I wonder "IF" your motorhome has a mother ????

[Retired House Husband]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>I wonder "IF" your motorhome has a mother ????

<HR></BLOCKQUOTE>
Bad! Really bad!

ROFLMAO

[Zeema12]

DriVer:
Good one - humor tempers the storms of life, as does viewing great art. Happy trails.

[DriVer]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Zeema12:
"humor tempers the storms of life" <HR></BLOCKQUOTE>That was exactly my purpose. A bit of levity is not intended to annoy anyone but to bring a little silver lining to the overall conversation.

Humor is good when it's not mis-directed or pointed at any single person.

[ISLAPP]

If you determine that it is fan belt related, make sure they put the right belt on!!
When I bought my '03 on a '02 chassis this past Nov., it had a squealing noise or slipping noise. I thought maybe it was from sitting at the dealership for several months. Ford replaced it and it was quiet for about 2 months then it started making noise again. Took it back and they determined the belt tensioner was bad so they replaced it and again put on a new belt. That lasted another 2 months. Now, as of today, they called Ford hotline and was told that they were using the wrong size belt!!! I dont know any more of the specifics yet, but they are ordering the so called correct size belt. I wonder if they had been putting one on from a previous year V10 and Ford had slightly changed the size of it when they boosted the horses and the and torque. But in all my problems, I never considered the noise a "whistle". It was always your typical squealing or maybe "rattling" that you get from belts.
Mike

[Zeema12]

ISLAPP
My '03 Infinity MH is also on an '02 manufactured chassis, so the wrong belt type is another possibility along with the idler/tensioner. I don't know if 'whistle' was the best word choice to describe this problem, but that's what it seems like - very shrill, high pitched, unlike any accessory drive belt/pulley problem I've experienced before, plus it never occurs at start-up or under normal highway driving, turning air on/off, etc. just at high rpm hill climb. It's going to be two or three weeks before I can get the rig to my dealer, but I did check the engine from inside the MH and tugged on the top-most belt - its tension seemed ok, but there is what seems like a tensioner wheel, this is smooth surfaced, not grooved or V'd, on the right top side (looking forward toward the radiator) which is pushing down on the belt vs. the usual where the belt runs around a grooved pulley wheel; anyway, I was able to turn this wheel by hand and make it slip on the belt. Is this the tensioner/idler pulley that you and others have mentioned? (it's very hard to see the complete drive belt setup on my rig either from top or bottom).
From - Mike

[Fossilhog]

My 2 cents. After sitting for 2 months my 02 Adventurer with 15,000 had the fan belt whistle. I was able to see some rust deposits on the idler. Local mechnic tell me to do this:
Get some Delectric grese and coat the belt, then drive it for 100 miles or so and the rust should polish right off. So far after just running it in the back yard for a few days on and off, the whistle at idle is gone but comes back at various RPMs a and is slowly going away. Time will tell.....

[LVJ58]

Zeema12, Our 2000 rig occasionally does the whistle thing when pulling grades at high rpm's. The last time it started the whistle, I turned the HVAC control that directs air either to dash, floor ect. to a different setting and the whistle stopped which makes me believe it comes from the HVAC control unit on the dash. Possibly a vacuum leak somewhere in the unit, but what doesn't make sense is the manifold pressure (vacuum) normally becomes less when under hard acceleration. Go figure--

Good Luck, Jim