Shifts late into 5th gear.

[electro452]

I just bought a 1995 protege for my son for school travel. It had the 1.5 engine and is a Dx model . We bought it from a estate sale and the lady who owed it had it in the garage but only drove it to church and around town, so it has only 58000 miles on it. I had the tranny flushed and filter changed, oil changed and radiator flushed before we drove it home 400 miles. It ran good but I did notice it would get to about 60mph before going into the last gear on the freeway. All the other gear seem fine and shift easily and smoothly. Lately my son says he has to take his foot off the accelerator at about 60 to get it to go into the last gear. Anyone have any idea what could be causing this? I was thinking a shift solenoid but since this doesn't have a OBDII in it I'm not getting any code.

[jeffcoslacker]

It's hard for me to judge if it is a matter of an actual problem, or unfamiliarity with this drivetrain...I have a '97 DX with the 1.5, but it is a manual.

The 1.5 is obviously NOT a big torquer. In fact I would rate it at the low end of adequate, but I consider it a fair trade-off for the 40+mpg I can squeeze from it. But even though we just have what I would consider mild hills on the highway here, sometimes with the A/C on it can really struggle to maintain a constant speed and really wants a downshift to 4th (which I deny, I just let the speed bleed off unless it gets ridiculous).

But having to fully release the accelerator to get an upshift to OD sounds wrong. I have a couple of thoughts, but nothing too useful, I'm afraid.

I am NOT a fan of flushing automatic transmissions. You know how people have a stroke when something that was perfectly happy where it was breaks loose and finds its way into somewhere it shouldn't be? That seems to happen with older vehicles when they get flushed. I would always just do a pan drop, filter, and partial fluid change. Blowing all the crud backwards out of the filter/screen and sending back through the hydro circuit is insanity to me.

Japanese auto units often seem to have small screens in the valve body to protect from jammed valves due to small wear debris, but they can cause problems when they get stuffed and reduce fluid pressure through that part of the circuit. Shifts then can then come at inappropriate times, be harsh, or not happen at all. So it's possible that could be a factor. But don't despair yet.

It would be good to know if it uses a throttle detent cable that goes to the valve body. A lot of earlier (prior to OBDII) cars did, instead of the trans getting info from the throttle position switch and other readings to determine shift points, they used a simple cable that came off the throttle assembly and went to the trans valve body, where it manipulates a valve that regulates fluid pressure, giving the valve body some sense of what kind of load the vehicle was experiencing. Most common complaints when they were out of adjustment where "hunting" in and out of OD excessively, or failing to into OD at an appropriate time. You can look and see if it works this way. There may be an answer there if so.

Has he tried using the OD cancel button (I assume it has one) to take it out of OD once it's in, and then see if it will shift back into OD when the button is turned off? When you do this, you are manipulating the OD solenoid directly, so if it seems to react quickly and appropriately to that, it would at least be some indication that the solenoid is functioning well enough.

Other factors, before I forget...excessive drag (seized brake, etc)...not all too uncommon on low mileage, older vehicles...with a little engine, dragging a sticky brake is like pulling a trailer, and it will be very hesitant to go into OD. Ditto for poor engine performance.

If it doesn't use a throttle detent cable for determining engine load, it probably calculates it by way of a combo of VSS (vehicle speed sensor) and MAP (manifold absolute pressure) and/or MAF (manifold air flow) readings..."seeing" intake vacuum level/airfolw and vehicle speed is the next best way to estimate load. If there's anything wrong that would corrupt those readings, it could affect the way it decides to shift, particularly the OD shift. So anything else that might seem unrelated could actually be a clue...if it's ever hard to start, or idles too high or low, something like that.

My '97 was throwing a persistent code for lean condition that was vexing me until I had the intake duct from air cleaner to intake off to do something unrelated...and found that it was severely cracked and sucking air in the "pleated" section where it bends towards the throttle body. That was the source of my code, as well as several nuisance but very transient performance problems, and if it was an automatic, probably could have had trouble like you have. Very possible. So I'm saying don't discount any other small symptoms it may have as unrelated, they might actually be pertinent. Like speedo/cruise control issues...people often neglect to mention these, when in fact they can be related to a failing VSS, and cause other issues...nothing is beyond suspicion, anymore. Too many things are integrated into other things, anymore.

So...rolling resistance...after driving a while stop on a flat surface, put it in neutral, see if you can push it fairly easily. If so, that's not the issue. If the engine is responsive and feels lively enough to you, that's probably not the problem. Try playing with the OD cancel switch and see how it reacts.

Also, there is a relationship between engine load, upshift, and the TCC (torque convertor control) in automatics...the TCC physically locks the two sides of the torque convertor together under low-load conditions, to create a no-slip operation for fuel economy...but if it locks up prematurely, it can place too much load on the engine and thus through the feedback described earlier, make it hesitate to want to upshift further. And the TCC needs to unlock before it will attempt a shift...if it's sticking, that can be trouble. TCC's usually won't try to lock until 3rd or OD is reached, with light engine load, and above 40 mph. If it was sticking and failing to unlock when commanded, in preparation for the upshift, it wouldn't upshift.

With a tach, the TCC's operation is pretty easy to see. With small engines, you can usually feel/hear it too...if you're cruising under light load in high gear, after a few seconds there will be a slight drop in engine rpm (about 200 rpm) and a change in the pitch of the motor as it takes on the additional load. In cars with bigger engines, it's not as noticeable.

Cruising under light throttle, say at 50-60 mph, while holding the throttle constant, if you toe the brake pedal just enough to light the brake lights but not really apply the brakes, you should feel/hear/see the engine speed up slightly as the TCC unlocks. It reacts to the brake light switch to unlock, providing the same action as when you depress the clutch in a manual as you use the brakes.

The good news is, TCC's in Asian vehicles rarely fail.

Good luck. I'll post more if I think of it. You've probably figured it out by now anyway. LOL...

[electro452]

Thank for the detailed reply.

I thought about the tv cable maybe sticking. I have a ford escort that has the same trans as the 95 Mazda Protege and i had to have mine replaced when I had the trans rebuilt. I think the issue is exactly what you stated with small engines. They will run at a higher tach under load and on grades to achieve the necessary speed and sometimes appear to be not shifting. I drove the car again last week after replacing the side motor mount due to some vibrations and thought it shifted pretty smoothly through all gears. The fluid is still nice and pink after a about 1000 miles on the filter and fluid change.

I do agree with the flushing sometimes causing issues in itself but in this case I felt it couldn't hurt since it seems to be shifting late in the last gear already. But as a general rule I only change filter and pan fluid and avoid flushes. I wish Ford and GM would put drain plugs on the trans pan like honda and Hyundai. Makes it nice to change fluid only every 10000 miles or so..

Anyway, all seems ok so we'll keep a eye on it and see what happens....

[electro452]

I do another unrelated question. This Protege doesn't have a tach on the instrument cluster. I really like having tachs because it helps to monitor how the engine is doing. Can I take a instrument cluster out of the same year , make and model Protege that has a instrument cluster with a tach and switch it with my instrument cluster?