98 Ford Expedition
Thread Starter
|
New User
Joined: Nov 2005
Posts: 6
Likes: 0
98 Ford Expedition
I have a high-pitched whining sound that has occured more often over time when I start my expy 4.6 L. It is not necessarily when it is cold or hot if you rev truck above 2000rpm a few times it will go away. Also, when you go above 30mph. I have systematically replaced a number of components. I started with the fan clutch, the bearings were worn, replaced and still have the noise. I changed the IAC valve sensor, idler and tensioner pulleys, new alternator, A/C pump and P/S pump as well. The Expy has 125,000 miles on it, other than the noise it works great!! I am getting no engine codes which leads me to believe that there is something mechanically wrong. I would much appreciate any tips as to where I might go next!! Could it be the bearings in the water pump (no signs of leaks)??
<!-- / message --><!-- no sigs except when logged in -->
<!-- / message --><!-- no sigs except when logged in -->
Junior User
Joined: Jul 2004
Posts: 59
Likes: 0
Have you replaced the belt? I think your looking in the right area, but after replacing all of those components I can't believe you didn't corrected it. Maybe something to try is to start it without your belt on ....... I know this is a no no, but running it from a COLD state for a minute should eliminate all of the possibilities in that area of the engine and not harm your Expedition. No doubt you'll have CEL codes thrown, but they should go out after a few run, stop cycles once you reinstall your belt.
My two cents.
My two cents.
Thread Starter
|
New User
Joined: Nov 2005
Posts: 6
Likes: 0
98 Expedition
Thank you for the reply 99Expeditionxlt. I took the truck to my friends shop and he replaced the belt under warranty. Still no change!! Shop guys did suggest running without the belt as well. I will post results later. Another theory I heard at the shop was the timing chain tensioner.
Thread Starter
|
New User
Joined: Nov 2005
Posts: 6
Likes: 0
Ford Exp Whining
I gave up! Also, I no longer own the SUV. I am now a very proud owner of a 2000 Ford Excursion LTD with a V10. Awesome vehicle. When I made the move to the Expedtion I thought it was great. The Excursion is all and more better with the 1 ton undercarriage. Back to the Expedition, the only thing that I did not replace on the front of the enginge was the water pump and the timing chain tensioner. I have mentioned this problem to a number of good mechanics and they collectively thought that it was an inherent design flaw with the alternator. The whine appeared to coincide with fluctuations in temperature summer/winter. This is a similar situation to the Chev trucks that have a transmission whine! Hope this has been helpful.
