Magic mile reduction

[Leeblev]

Couple of weeks ago, I started to Washington. Drove about 100 mi N. on I-5 with little traffic, road smooth and delightful and engine purring like a kitten when suddenly my Low Air light and buzzer went off. A check of my gauges showed the front tank normal and the rear reading 0. Light and buzzer cleared. Rear tank jumped back to normal. Front tank continued operating normally. Then buzzer and light on/off intermittently and growing longer each time. It was obvious that my rear tank was functioning properly as I had good brakes and my suspension didn't collapse. Each time the warning stopped, the gauge for the rear tank "jumped" back to normal and it was obvious that the compressor couldn't replace the air that quickly. Finally decided that I had better pull into a rest area for the rest of the night and go home and get the rig into Freightliner. Did so.
Took the rig into Sacramento Truck Center last Tuesday. They felt the problem was a faulty air sensor microprocessor. Left it there to change, and to service the rig. When I got to Sacto, the mileage on the rig read 79406 miles. They called me the next day, telling me that my exhaust manifold was warped and needed changing. Authorized it. Picked up the rig on Friday. Running good and normal (I thought). Got about 10 miles down the road towards home and glanced at the odometer showed 33+++ miles! Of course I did a double take and then thought the odometer was in Kilometers. Checked it-nope reading correctly for the 33,+++ miles. Since it was past closing time for Freightliner, drove on home. Called the following Monday. They have no clue how that could have happened. Gotta take it back to check further.
Anyone have this happen? If so, what was the cause?
I know it is nice to have a lot less miles than you think, but not this way!
Any help will be appreciated.

[fcooper]

gatorcq wrote:
Fred, thank you for the Links, as I could not locate mine.

I've kept up with that info in case mine fails, but so far so good.:)

Fred

[gatorcq]

Fred, thank you for the Links, as I could not locate mine.

[ncrowley]

The rear air gauge is not for the rear air bags but for all the air bags if it works like my coach. The front gauge is for the air brakes. Therefore, if the rear air goes to zero, you will know it from a very bouncy ride and not by a test of the brakes.

[fcooper]

I think gatorcq has the correct answer.

Your profile shows a 2001 36' Kountry Star DP. On the Freightliner chassis during this period, there was a batch of VDC's (Vehicle Data Computers) that had cold solder joints. Your symptoms of air pressure warning, etc. fit the symptoms reported from a VDC with cold solder joints.

Some owners have been able to repair them by carefully resoldering the joints.

I do not know if repairing the VDC will correct your mileage problem, but it certainly can not hurt.

Go to the link below and download the file VDU/VDC repair and it will detail the problem and the corrective actions.

VDU/VDC repair instructions

If you want to understand how your instruments/guages/odometer work, use this link to download Freightliner service bulletin 54-12.

Freightliner service bulletin

For additional free help, call the Freightliner help desk at
1 800 FTL HELP. Have your VIN number handy.

Fred

[westernrvparkow]

When you go to sell your rig and have to declare "True Mileage unknown" that low mileage reading on the odometer won't be so sweet. Sounds like the odometer link got disconnected. Combined with your other issues, it sounds like you might have a wiring harness going bad or some wires are rubbed bare and shorting out intermittently Causes could range from heat, to varmits, to sloppy installation, to just plain bad luck.

[Leeblev]

I guess I'm dumb, but what is a VCD?

[Leeblev]

During servicing, they found the warped manifold. has nothing to do with the problem with the sensor. Just noted as part of what was done to the rig while at Freightliner.
My rig is on a Freightliner chassis with a Cummins engine.

[gatorcq]

how do you get from a sensor to a warped manifold?

Plus what is your chassis? Freightliner? If yes then a cold solder joint inside the VCD.