Big Prob - Been to 2 mechanics, still not fixed!

[JLS81]

I have a 2008 Mercury Mountaineer Premier - 4.6L - AWD- and im just about to give up! It's been doing this weird thing, and the only thing i can liken it to, is driving over rumble strips on the road... its a weird grinding/vibrating sound, and when this sound is occuring, im going about 45 mph and the rpm's jump up and back down...this weird sound/vibrating..or whatever you want to call it, occurs at other speeds too, but 45 mph seems to be the sweet spot....Anyway I took it to a mechanic, he told me it was my rear differential... alrighty well hes the mechanic and i had no choice but to trust his diagnosis....anyhow, well it took him a month to "fix" it..got it back finally, took it for a spin...and it was doing the same thing it was doing when i took it to him! - so over 1000 dollars later, still no fix... tried to get him to fix it again, but he kept putting me off, and off...SO, i take it to another mechanic, they tell me its the transfer case... took 3 weeks to fix... almost another 1000 dollars later, got a call, was told it was ready to go...i go pick it up, take it for a spin...and guess what.. its still doing the same thing again!!!...if its not either the rear differential or the transfer case...does that leave it to be the front differential?? ive been reading a lot about these types of problems, and ive come across some other peoples post about similar issues and it looks as if the problem could be that i need my transmission flushed and new fluid put in..?? something about torque converter shudder?? could there be an awd problem?? Im seriously at a loss! im a single mom and this damn vehicle is hurting me financially and i keep getting taken advantage of by mechanics...I cant afford to get screwed over anymore - can anyone help?? Please?

 

[boominXplorer]

You have an engine miss fire it sounds like. Have you replaced your plugs yet?

 

[Flag Gibby]

If there are no diagnostic trouble codes then it is a hard one to troubleshoot, but with the RPM's jumping you should have some sort of code to go off of whether it is in the transmission or somewhere else it is hard to say. I definitely think that it needs to be scanned while driving it to pinpoint the problem and not just throw more money at it. In this case it may be worth the $100 for Ford to run the diagnostics on it to pinpoint the issue since they are guaranteed to be able to read/see transmission and engine trouble codes.

 

[JLS81]

There has never been any dash panel lights on... ever.. the thing has never once thrown a code... its possessed.

 

[banditxp]

this will prob help.
look at the last post
http://www.explorerforum.com/forums/showthread.php?t=396736&highlight=45mph

also just do a search on this forum for 45mph and lots comes up

i would go with spark plugs or coils.
but also paying 50-100$ at a Big Good Ford Dealer is worth it to make sure its not something else.

and the good part if you run into problems at a ford dealer here is this forum has a Ford customer service rep that watches post and helps people that run into problems with ford dealers. so in your case so you stop being screwed by stupid mechanics just go to a good dealer.

 

[Old As Dirt]

45 is the shift point for overdrive. Try locking out overdrive (with the shift lever button on my 2007) and see if it does its thing. If not - transmission.

John

 

[JLS81]

Ok, i will try the overdrive off button and see what it decides to do... but if it STILL does it, are you saying that my transmission is going bad?

I've been reading a lot on here and elsewhere, and im really wondering if i should just have the transmission and torque converter drained, flushed and new fluid added, along with an additive, something called Dr Tranny Shutter Stop... idk. Im about at my wits in with this thing and really close to just taking the hit on trading it in and getting something else

 

[63falcondude]

I dont know about the rpm fluctuation but the shuddering might be your wheels being a bit crooked. Try loosening the lugnuts and jacking it up, then make sure its on straight and tighten again to about 100 ft lbs.

Doing this fixed a horrible "death wobble" that I got on the parkway. Although it sounds like you've got something different going on, it's worth checking since its free to do.

 

[morbid81]

the speed related sound, sounds like wheel bearings to me or even the Throttle position sensor on the rpms jumping, have you had a alignment lately or tires balanced and rotated? ABS sensor might be bad on the rear diff. Is it clicking in turns? could be bad cv joints. maybe bad u joints on the drive shaft. have all the fluids been changed recently? i don't suspect a transmission issue. but outside of hearing the noise or driving the vehicle its hard to diagnose

 

[JLS81]

Im going to make a video of what its doing, and post it on here....hopefully it will be good enough quality to figure it out

 

[JLS81]

Ok here is the video, I uploaded it to youtube

https://www.youtube.com/watch?v=F40UYjv6dz0

The video is a little shaky, but after the first 12 seconds you will see what I'm talking about...If you watch it, make sure your volume is up, because the sound is a little faint.
The grinding/vibrating/rpm jumping thing, happens once it does its final shift (at 45mph) and the rpms drop back down...thats when it starts acting like that.

I had this thing at 2 different mechanics, 1 said rear differential needed replaced..so i paid for that, still same prob... other mechanic said transfer case, i paid for that, still same prob.... so here i am... thanks for all your input guys

Note: if i romp on the gas while its doing this, it will stop, but if i drive it gently, it acts like this... i guess my truck just likes it rough

 

[JLS81]

This truck needs *****slapped

.

 

[D Hook]

No access to video.


"Content Warning

If the owner of this video has granted you access, please sign in."

 

[Flag Gibby]

I know that it is not what you want to hear, but the best thing you can do is take it to a Ford dealership where they have the experience with the vehicles and the tools to read pending diagnostic codes from both the transmission and engine while driving it so that you don't continue to just throw money at the vehicle and actually get it fixed. Ford is not going to jerk you around like the other shops did, they will not perform a repair unless they know for a fact what the problem is and they won't keep the vehicle for a whole month just to fix something that should take no more than a week at the most.
JLS81, based on your last post I am really starting to lean with BoominXplorer on checking the sparkplugs/coils but once again a code reader would be able to tell you that so that is why I am insisting on taking it to someone that can read engine and transmission diagnostic codes. If you have never had the plugs replaced on the vehicle they are past due and are most likely going to be a royal pain to remove depending on if your 08 has the redesigned heads on that V8 or not.
Well, you have heard it from three of us here now (get the vehicle diagnosed by Ford with a high probability of it being a plug problem) so I will just wish you good luck.

 

[colintrax]

I'm with Flag Gibby, take it to Ford.
Don't ever go back to those other mechanics, they clearly aren't qualified.

IMO it's your torque convertor, that'd explain the RPM change. But without being there, its hard to say. It could very well be spark plugs causing a misfire and causing the transmission to unlock the torque convertor or down shift to correct for the loss in power.

Either way, go to a Ford dealership and nowhere else.

 

[JLS81]

Ugh, I'm sorry... I thought the link worked... didn't realize there was problem.. I'm reuploading the video again... ill make sure it works this time

You Tube is taking forever to process my video...ive tried convering it through realplayer to make it faster but realplayer wants me to pay, F that.
IDK where else to upload it to

 

[colintrax]

Ugh, I'm sorry... I thought the link worked... didn't realize there was problem.. I'm reuploading the video again... ill make sure it works this time

You Tube is taking forever to process my video...ive tried convering it through realplayer to make it faster but realplayer wants me to pay, F that.
IDK where else to upload it to

You can upload a video if you want, but you should still go to a Ford dealership. You don't have to have them do the work, just get a diagnosis. Any shady mechanic can drop a transmission and swap torque convertors (easy if you have a lift and experience with vehicle repair) or replace the spark plugs.
Or if you really want, replace the plugs and coils. They're maintenance items anyways. If the problem still persists. Then go get a diagnosis at Ford

 

[JLS81]

Ok, I think im going to have a tune up done this weekend... any idea about how much that will cost me?

 

[JLS81]

Ok, I think this will work now. Here's the video. If you watch it, make sure your sound is up pretty loud

https://www.youtube.com/watch?v=F40UYjv6dz0

At :11 seconds you can see the rpms drop back down after it shifts, and then its starts its crap

 

[JLS81]

Could there be an engine misfire, that has never given me a check engine light, no codes...and makes the vehicle do this??