I took my truck (2005 F250 6.0) into my local dealer Wednesday for all the 150,000 mile maintenance.

I had them change the oil, fuel filters, coolant, tranny fluid, transfer case, differentials etc.

While the the truck was there, I wanted them to recalibrate my speedometer for my 285/70/17 tires. I gave them the revolutions per mile info from Bridgestone.

When I picked my truck up, the dealer informed me that they could not set the speedometer to the exact revolutions per miles that I gave them. They told me that with the computer in my truck, the had to select a tire size, not the RPM. They said some trucks they can set the RPM, but not with mine. They chose a tire size as close to mine, about 6 RPM off from the info from Bridgestone. So my first question is, is my dealer full of crap?

Secondly, when they were recalibrating the speedometer, they reflashed the computer to the newest flash. Yesterday, the truck was running rough with white smoke when I first started out in the morning and on the way home from work. After a minute or so it went away and runs fine. However this morning on the way into work, I turned around a corner and the truck just lost all power and gave out a bunch of white smoke out the exhaust. I pulled over and it went away and ran normal. Is this just my truck relearning the new stragegies or is there something else a miss? I'll admit I haven't drove many miles in the last two days, just back and forth to work.

I appreciate your thoughts.

 

6rpm?

What % is that of the total?

Say it is 656 rpm... that is around 1%

It seem to me that you get that much difference from:

A) whether you inflated it "hard" vs. "soft".

B) if you measure rpm "new" vs. "worn" tread.


You are sweating over a lot of nothing.


If you are really freaked out.. get a GPS and measure your speed.

 

It's not so much the 6 RPM error I'm worried about, its more does my dealer know what he's doing with my truck.

I had read other threads before I took my truck in that said they should be able to enter the exact RPM.

 

They told me the same on my tires I'm about 5mph off

 

There is a range that the Ford dealer equipment can set to.

Apparently some of the scan tools like AutoEngenuity can do a bigger range.

Check with people who know that on here --- which is not me.

 

I've heard ae will do up to 37" tires. I have not had the chance to use one or the cash to buy one. Its on the long list of wants though.

 

I thought you entered revolutions/mile as well, but my AE lists tire size in 1/2" increments.

 

1/2" increments of tire size ?

Is that in diameter?

If so, a quick and dirty calculation will show.. accuracy.

 

About your white smoke/rough running/power loss, check your oil level. They may have overfilled your crankcase. Also check your invoice for weight of oil just to be sure.

 

so ford can change your speedo calibration????? you dont have to by that superlift true speed calibrator if you get a bigger tires size????

 

Depending on the year, we at the dealership can no longer input tire RPM as data in most cases. When programming, you have to choose a tire size from a list, and that list will only be comprised of sizes that are offered in different option packages from the factory.

The reasoning is that altering the tire size alters the emissions output of the vehicle, and by allowing techs to input variables that have not been certified as emission compliant, Ford puts themselves in violation of numerous federal laws. It is just a way for them to CYA, unfortunately for us.


Jay

 

I had a Ford tech calibrate my speedo with 37" tires. He got it real close reading 60MPH and actual is 61.5.

 

2.5% isn't that close, even with 0.5" tire size increments its about 1" off.

 

First FireMe, thanks for the info on speedometer calibration.

Now for an update on the power loss/white smoke.

The truck ran fine last night and I drove 100 problem free miles today.

Tonight, the wife and I went to dinner and as I pulled into the restaurant parking lot, the truck lost power again. I parked the truck and went into dinner, hoping it would run fine when we were done with dinner.

Well, it didn't. The truck started fine, idled fine, went into gear fine. But when I pushed the accelerator pedal it would lug and surge forward with a lot of white smoke coming out of the exhaust. I tried driving around the parking lot and I couldn't get enough power to reach 5 mph. I restarted the truck a couple times and every time it was the same thing. It seems like its missing. The factory boost gauge never moved off 0 boost.

So I got a ride from my grandpa and left the truck at the restaurant. I'll go back over tomorrow and see if I can figure anything out. I guess I'll try pulling the EGR valve to see if its clogged/sticking and I'll drain the HFCM see if any crap comes out of the drain. Beyond that I'm looking for help.

Needless to say, the wife is not happy for dinner being ruined by "the money pit" so I appreciate any help that prevents having to call a tow truck.

 

That sounds like EGR valve or possibly EGR cooler.