I don't buy it. About all I could imagine happening would be an ABS light if tire stagger front to rear was too large. There's no traction control so the engine would keep running fine. The computer doesn't know what gear you're in so a fault related to RPM vs MPH wouldn't be possible. If it's going into "failsafe", there should be a code that caused it. What is that code?
The dealer said there was no code associated with the event, but the ABS and handbrake lights did go on every time it happened.
What are the exact sizes (width and aspect ratio, molded on the side) of the tires they put on the car?
I'm not near the car now, so I don't know the numbers, but the tires they put on are significantly lower profile than the originals.
WTF? Are they waiting for the tires they installed to magically change size?
The answer is, duh, to take off the tires that they should never have installed on the car, and install tires that are the correct size.
The oem Goodyears and the Bridgestones have diameters almost exactly the same, and have been used by hundreds of GT owners.
Put the Bridgestones on and find a new dealer who has an IQ above 50.
Yeah, I've been preoccupied with other things. This wasn't a top prioroity. I've got stuff cleared up now and can focus on this.
Yes, ABS looks at SS's. I doubt the engine looks at them.
I'm saying that, if the tires aren't causing an ABS code, smaller tires in the rear is equivalent to the 3.9 ratio, and the 3.90's don't cause engine problems. His engine problem is something else
I'm pretty certain it's the tires. There were no problems before the tire change and the problem started happening the same day they put on the new rears. Too much of a coincidence to be anything else.
Where is your dealer located? Sounds like they screwed the pooch.
John Kennedy Ford, Phoenixville PA. It's where I purchased the car in 2007. They've been good up until now. Needless to say, I'm disappointed with the whole tire thing.
As far as I know from reading info here and in the manual, the ABS and ECU are separate systems. Kendall or anyone else, do you know differently? Is there any signal from the ABS to the ECU? If they are separate, then the ECU does not compare front and rear wheel speed, so GT@50 probably is correct that something else is causing the behavior.
However, Mark06GT: you should still insist that the dealer put the correct size Bridgestones on the car. They should know not to put significantly different tires sizes on a modern car with ABS. Even if it does not fix the loss of power, it will ensure your ABS works correctly. Then see if the behavior continues.
I totally agree. That will be my project this week.
And Mark06GT, one other thing: check the intake boot and vacuum/boost hoses on the intake side. One of those coming loose will cause similar symptoms.
I will take a look, but I would hope they would have noticed that.
Thanks all for your help. With your input, it should be easier for me to get the dealership to do the right thing an replace the tires.