Questions and Answers

Mazda Protege A Temperamental Child Q. I'm at my wits' end. My 1996 Mazda Protege LX, 4 cylinder, automatic transmission with 104,500 miles has always been very reliable and I love it. But lately, it's been more of a temperamental child. I don't know how much of this is related to the current situation, but I'm going to include it just in case it's pertinent.

About a month ago, I went out at lunch to find my car wouldn't start. I called a local garage who came and jumped it and asked me to come to their garage so they could check the battery. The battery tested bad so it was replaced.

Shortly after that, I noticed that the engine seemed to rev really high occasionally, sometimes when accelerating from a stop, but also sometimes as you were just driving along. I took it to a local shop fearing I needed a new transmission, but they diagnosed the problem as being in the boost valve and recommended just replacing it. So that was done and it seemed better.

Then maybe a week later, I was driving to grad school on the highway going about 70 mph, when I noticed that the cruise control light on my dash was flickering. When I got off the highway, I noticed that my turn signal lights were not blinking rhythmically, they were slower than usual. By the time I got to campus, my radio had spontaneously shut off.

I didn't have time to do anything before class, but as soon as I was done I took it to a shop and told them what had happened. The mechanic suspected the alternator, but it tested fine. Unfortunately, I didn't have the symptoms between the school and this repair shop so they didn't get to see it in action.

I drove home a back way that would take me through small towns in case I had problems, didn't want to have to stop on the interstate but didn't have any problems on the 45 mile trip. I took it to my local mechanic who's done a lot of my routine maintenance and I have a good relationship with, but he drove it around town and couldn't find any symptoms. I did have him do an oil change since it was due for that anyhow.

But wait - there's more. The next week I was driving the car to school and I noticed the same problems. This time though, I noticed a definite loss of power when I used the turn signals and when I turned on my headlights just to see what would happen, the car almost died completely (I turned them off very quick so it didn't). The tachometer and speed would also drop almost to zero and then fly back up to normal when something electrical was activated. I drove straight to the same shop, left the car running, and told the same mechanic about what was going on.

They tested the alternator again, but it still seemed fine. I left the car with them for the day so they could drive it and try to have the same problems. They took it out on the highway and fortunately, the same thing happened. They said they thought the problem had to do with me needing new tires, which I knew, but had put off with all this going on, because there was a lot of vibration and their theory was that after driving on the highway for a while and warming everything up, the vibration was interfering with electrical connections. So I had to get a new set of tires and that did reduce the vibration significantly.

However, I'm still having problems. I'm still having some sort of electrical/transmission problem. Now, if I'm going 60 mph and I step on the brake, I lose a lot of power for a split second and then it comes back. The rpm and speed drop dramatically and then return (which is very disconcerting in traffic!) It doesn't happen if I'm going slower than about 45.

I don't know what to think anymore. I don't know who to trust and am very conscious of the fact that I'm female which puts an automatic bullseye on me to a lot of mechanics. I don't know if I should keep trying to get this repaired, or if I should be looking for a new car. I've been hoping to keep this car until I graduate in spring, but after already putting $550.00 into it altogether in the past month, I'm trying to decide if it is worth it.

Do you have any idea what the problem is and what it would cost to repair? Is it worth repairing this car at this point or looking for another car? Any help you can give is sincerely appreciated.

Thanks so much!
Jennifer

A. Oh boy! You got a good one here Jennifer. I really wish I had this one in my shop. Has anyone tried to pull up any codes? The Powertrain Control Module (PCM), Transmission Control Module (TCM) Cruise Control Module (CCM) all store Diagnostic Trouble Codes (DTC). They may give us a big clue where to start looking.

Another thing to try is to make up some fairly heavy jumper wires and attach them from the engine, transmission and frame directly to the battery negative terminal. If the problem disappears, then it is a ground problem and easily corrected by repairing the present factory grounds and/or installing new grounds.

Then I guess I would do a current draw test. An inductive ammeter can be hooked up and we can see how much current is being drawn when this happens. If there is a major current draw, I would suspect a short before the fuse and relay box.

I would double check the battery again very carefully. If they will, let them replace the battery with another new one to see if that takes care of the problem. I would also check the battery cables. Battery acid can get inside the insulation and cause a high resistance connection which could be causing the problem. Look at the cable terminal ends. They are kind of skimpy and I have seen them break, causing a poor connection.

If all else fails, I would take it to a Mazda Dealer and let them drive the car with their scan tool hooked up. That would seem to be your best hope in locating this problem.

Please, let me know how you make out with it.