At around 20,000 miles, my 2003 EB Explorer (not AWD) started making a noise when decelerating at highway speeds (over 50mph). The first time I noticed it, I thought it was a flat tire. It's a thumping noise that occurs about twice per second and shakes the entire vehicle.

After 12 days at the dealer, they've determined that the noise in the result of 4WD/HI repeatedly attempting to kick in. They've hooked a computer up to all the sensors and don't see anything abnormal. All four tires check out okay. They've had Ford engineering involved for the past three days, but are no closer to solving it. According to the dealer, Ford hasn't seen this problem before.

Has anyone else ever seen this problem?

A related question: Since the first day I had this truck, it starts in 4WD whenever you pull away from a stop sign or traffic light and then shifts out of 4WD back to 2WD at around 25-30 mph. Is this normal or could it possibly be a symptom of the same problem?

 

Could be a Friday or a Monday built SUV.....I had an F150 that baffled everyone.......Ford was never involved, though...

Thank god it is still under warranty.....

 

Well, they discovered the problem -- it was the tires. At 20,000 miles, the dealer replaced the left-rear tire due to a puncture in the sidewall. Now, that newer tire has a circumference of 95" where the other three are 94" around. (The first tech who checked the tires screwed up -- they went back and rechecked and discovered the difference.) They tell me that all four tires must be identical. Worst case, I may have to spring for four new tires.

Is this a well-known issue with the new Explorers? I'm kind of in disbelief that a flat tire could end up costing you $800 because of an overly sensitive automatic 4WD system that you can't override.

Anybody else out there encountered this problem?

 

You might look into having the new tire shaved. This will take away some circumference and keep you from having to buy 4 new tires right now. A race prep shop should be able to do this because they do it all the time for drag racers. They just might not be used to doing it for SUVs

The fact that a newer tire turns the 4WD system on seriously concerns me. If we get a flat tire, are we realistically expected to run out and replace all 4 tires? How is it going to perform with a spare tire on it? If it can't take a 1" circumference difference, it definitely won't handle well with the spare.

BTW, do you think the air pressure could possibly be reduced on that newer tire to effectively reduce the circumference? The tire will flex more than the others, so would it travel a shorter distance per rotation? Just thinking out loud here...

Tim

 

Didnt someone else just have this problem?

What you describe about starting out in 4wd then going to 2wd (i assume you mean 4x4 auto, since there is no 2wd) suggests more of a problem. Maybe all that 4wd operation on dry pavement has damaged some drive components. That should not be happening in any case, its not a symptom of the current problem but maybe is the cause..Im skeptical of the tire diameter thing, lets us know what happens though.

Changing the tire pressure wouldnt change the tire diameter significantly I dont believe.

 

Here's the final update now that my truck is fixed: The entire problem was caused by the tires. More specifically, the replacement tire that the dealer put on the left-rear is one inch larger in circumference (95" vs. 94") than the OEM tires that came on the vehicle. The difference in size was enough to throw off the automatic 4WD. They replaced the left-rear with the 94" OEM spare and the problem disappeared.

All six tires (including the replacement) have exactly the same markings:

BF Goodrich Rugged Trail T/A
P245/65R17 105S M+S OT

Since there is no way to tell from the markings whether the tire has a 94" or 95" circumference, this could potentially bite a lot of people. The dealer tells me that the Ford Engineers were completely unaware of this issue.

The problem is, if I have to replace one more tire I'll have to replace the entire set since it will be virtually impossible to obtain an OEM version of this tire and/or confirm the circumference prior tp mounting it.

I would think that Ford would want to immediately send a service bulletin to all dealers regarding this issue, so that others don't go through what I went through. (Not to mention that this fiasco probably cost Ford and dealership thousands of dollars.)

 

Why does Ford seem to have all these problems with their tire suppliers? Is it that hard to make a tire a certain size?

Glad to hear you got it resolved. I thought that the circumference problem was because the other tires had wear that the new tire didn't. Isn't that still a problem? If you look at even losing 1/4" of tread (so 1/2" diameter) due to wear (which isn't anything really), aren't you still looking at a 1.5" difference between a used tire and a new tire (C=pi*d)? Hmm... That would make it hard to put a new tire one and have it run right even if Ford did get the right size tire. Just a thought...

Tim

 

Both the dealer and I had the same thought. We were both pleasantly surprised to find that the unused spare was close enough to its OEM brothers -- even with 25,000 miles on them -- to satisfy the automatic 4WD.

I hope that this is a very isolated occurence or else Ford (or Bridgestone) just might end up replacing a bunch of tires for free.

 

I can kinda understand why its doing that though. The rear is detecting a difference in the revolutions of the wheels and interpreting it as a slip as though its on ice or snow. It does sound a little sensitive but I bet if you were in a similar situation in snow or ice you would appreciate that sensitivity. Blame it on the original misdiagnosis by the tech, not Ford. If I were you I would complain to the service manager or even the owner of the dealership that the tech's incompetence cost you $800 and that for your money they should replace your tires and give you a free oil change or you will take your future business elsewhere and advice anyone and everyone that you know to avoid their establishment because their techs can't even properly measure a tire.
Use it to YOUR advantage!

 

Actually, this occurence didn't end up costing me anything other than the inconvenience of not having my truck for 13 days and knowing that they unnecessarily replaced parts and disassembled and reassembled most of the drive-train. The $800 statement was theoretical -- if I have a blowout now that I have no more OEM tires to turn to, I'll have to replace the entire set.

My larger concern is for all owners of 2003 auto-4WD Ford Explorers whose vehicles have the same tires as mine. You cannot purchase a matching tire at NTB, Pep Boys, or a Bridgestone store. And because the problem isn't well known, other people will go through what I went through. Neither they, the tire store, or the Ford dealer will know that the problem isn't related to the difference in wear on the new tire versus the other three tires on the vehicle -- it's due to the fact that the OEM tires from Ford are non-standard variations of a standard Bridgestone product.

On the hopeful side, perhaps there's just one bad lot of Bridgestone tires out there and the problem really isn't that bad; however, I hope that someone from Bridgestone or Ford grasps the potential seriousness of this situation and does some research to understand the scope of the problem.

'nuf said.

 

Okay, sorry. Let me apologize to Bridgestone. That's the problem with sending emails before your first cup of coffee.

The tires in question are BF Goodrich, not Bridgestone.

 

After the new tire swap does it still start off in 4WD.My 2002 does the same thing,but it has all the original tires on it.

 

Yes, that behavior still exists. The dealer couldn't tell me whether that was normal or not. The strange thing is that it doesn't happen 100% of the time. I haven't been able to figure out a pattern to when it happens and when it doesn't.