Posted: 4/12/2013 6:23:14 AM EDT
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Need some help. My son is having a problem with his 2002 Mazda Protege. It has 96,000 miles on it and has an automatic transmission. Car was/is very well maintained with all maintenance preformed and all fluids changed on time.
The problem which has gotten progressively worse over the last 6 months....... While driving, when he approaches 60 MPH, the car begins to shake violently and decelerates. He can be going along fine and when he hits approx. 60 MPH, the car shakes and slows down.... will not accelerate. He pulls over and stops. He can then proceed until he hits approx. 60 MPH again and the problem occurs all over again. He called me this morning and the problem is worse than ever. At first, it was just a slight vibration then the car would continue to go.... now it will not and he must pull over. The car has an automatic transmission with Overdrive. The overdrive is engaged by pressing a button on the side of the shift lever. I took the car for a ride several months ago when the problem was not as severe and I could not get the car to act up. I noticed that the OD light that usually shows on the dash would not light up when I switched between no OD and OD engaged. Also, I had to try several times to get the car to switch between OD on and off. I think and always thought that the problem is with the transmission and/or torque converter. At approx. 58 to 60 MPH is when the car shifts from "3rd" gear to OD. I don't know if the problem could be electrical or strictly mechanical or both. He has had the car to a competent ( they have always been good in the past) shop a couple of times. Last time was just yesterday. The shop replaced a "vacuum intake hose" which was cracked. Son said the car starts and idles better but he still has the above problem. So again, I think the problem lies with the tranny/OD because it seems the car acts up when shifting into overdrive. I will not be able to drive the car for a couple of days to try it out. I want to turn off the OD and try it and see if that stops the problem. Like I said, last time I drove the car, I had some problems getting it to switch OD on and off. I am not a professional mechanic but have done my share of repairs and rarely take may cars to a shop. I have done many break jobs, exhausts, shocks, water pumps, radiator replacements, drive shafts, u joints , couple of clutches etc. I have not messed with auto transmissions much but have swapped a couple out over the years. SO...... what do you think and what would you do?? Any help is greatly appreciated as my son really wants to keep this car. He had the timing belt/water pump done about 5,000 miles ago, just had new tires installed and I just put breaks on it..... so it is in good shape except for this problem. HELP please. |
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doesnt really sound like a transmission problem to me, but if you think its transmission related would take it to a transmission shop have them test drive it and actually see the problem occur, is where you should start they should be able to tell you if its transmission related or not.
to me it sounds like its engine related cause you cant continue to accel, if the check engine light is on you could have codes checked, maybe ignition related if the car is actually shaking seems like it may be misfiring, plug wires, coil boots, plugs all could cause cylinders to misfire and they often may only misfire under a load at highway speeds. seeing how you just had it to the shop, maybe take it back to them and explain the problem have them test drive it. |
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Quoted:
I think and always thought that the problem is with the transmission and/or torque converter. At approx. 58 to 60 MPH is when the car shifts from "3rd" gear to OD. I don't know if the problem could be electrical or strictly mechanical or both. Does the shifter allow him/you to keep it in 3rd gear with OD disabled? If so, what happens when the vehicle reaches 60 mph in 3rd? Does it do the same thing? eta: just reread your post and saw that you plan to try it. That would be a good place to start. |
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Son called yesterday and was able to turn turn off the overdrive. He said the car ran great and without the OD engaged he was able to acclerate past 60 MPH without any probloems. It appears that the problem is only occuring when the car tries to go into OD which is what I thought. I am wondering if this could be an electrical problem since it takes many attempts to turn the OD off or on by depressing the button on the side of the shifter. I don't know if it is even possible tlhat the problems electrical because electronics usuallyfail completely all at once don't they?
I am wondering if it could be valve or something in the transmission that controls the OD. Anyone have an idea? |
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Quoted: Son called yesterday and was able to turn turn off the overdrive. He said the car ran great and without the OD engaged he was able to acclerate past 60 MPH without any probloems. It appears that the problem is only occuring when the car tries to go into OD which is what I thought. I am wondering if this could be an electrical problem since it takes many attempts to turn the OD off or on by depressing the button on the side of the shifter. I don't know if it is even possible tlhat the problems electrical because electronics usuallyfail completely all at once don't they? I am wondering if it could be valve or something in the transmission that controls the OD. Anyone have an idea? Yes. Get the vehicle diagnoses by a decent independent repair shop. |
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+1 what everyone is saying.. Go get the codes scanned with a high-end scanner that the trans shop will have. Its a Ford FN4A and it probably has serious valve body issues that have know smoked the TCC. which when it tries to lock up the clutch its just slipping and chattering, but the valves in the valvebody wear into their bores and get wedged and stuck, and now the converter is stuck halfway between trying to engage and disengage. Look on sonnax's website theres a lot of info on it. |