GTUser

Discovered a major problem today and need y'all's help trying to figure out why the woven steel covering on my mazdatrix hydraulic line between the slave cylinder fitting and the firewall bracket is heating up and melting the interior lining.

Here is the story, last Saturday I opened my sunroof because it was abouve 60 and the weather was great. Well when I got home I couldn't get it closed so I moved my wife's car out of the garage and put the RX7 in. Sunday it was in the 20s and snowed several inches so I did not crank or move the car until today. Now when I put the car in the garage I did not let it completely warm up so I was prepared to do the unflooding if needed.

Today, almost a week later, I tried to start the car and the engine turned over on the first try but did not start. I also noticed that there was some smoke drifting up from the rear center of the engine bay. The next time I started the engine it was very sluggish, the starter had a hard time turning the engine over. It seemed that the battery didn't have enough juice to crank the engine. Yes, I had put it on a charger before I started this to ensure that it was fully charged. I turned the ignition off and tried to find where the smoke was coming from but it had dissipated before I got around to the engine bay. The next crank was the same the starter was slow and the smoke reappeared.

I jumped out and the smoke had again disappeared before I got to the engine bay. I started investigating the wiring to see if I could find some fried wires. Well, I grabbed the hydraulic line to move it and found out it was very hot! I had found the source of the smoke!

As I examined the the hydraulic line I found that the heat had melted the zip tie I had used to keep the line away from the coolant hose clamp at its firewall connection. I could not find a wire or connection that might be shorting out against the hydraulic line. What was really strange was that the pressure fittings on either end of the line were not hot, only the woven steel covering. The firewall bracket where the flex part of the line fits to the rigid line wasn 't hot, nor was the slave cylinder fitting.

Has anyone had this happen to them? I know the battery charge is being affected by a short some where, and I assume that this is the only reason that the hydraulic line is heating up and melting. Can anyone suggest where the short might be, and how the woven steel is getting hot but not the fittings or any adjacent metal parts?

This is a good puzzler for the Click and Clack guys.

Please post your thoughts, suggestions and questions.

Thanks,

Bert, the GTUser

TIIsport

Check the ground wire from the battery to the motor. Bad connection at motor end & the metal clutch line is trying to provide the ground connection - & heating up horribly.

Kenteth

damn i would have never thought that, awesome

Turblown

iTrader: (12)

I second that. I've had it happen to me.

SpeedFreak03

Good call! That makes sense! Running a new ground would prolly be your best bet, you would be suprised what weird problems magically disappear!

jacobcartmill

iTrader: (6)

good call. definitely check out that ground wire before its too late

GTUser

Thanks guys, I will check the battery ground on Monday. I haven't had a chance to do any further trouble shooting on it since Friday. I'll let y'all know how it turns out. I really appreciate the help on this. Mazda dealer just lost another $65 diagnostic job.

SpeedFreak03

Screw diagnostics, thats what this forum is for ! Good luck man!

GTUser

EGGS ACTLY!

GTUser

I have checked the system ground and traced it from the negative battery post, down the drivers side fender well (that is the left side of the engine bay looking from the drivers seat), where I found a copper ground connection. It continues on under the car to a terminal copper ground connection at its end. I found the terminal end under the car not attached to anything and I could not find anything that looked like where the ground should be attached.

So, you were definitely right on with the cause of my melting hydraulic line problem. My question is does the terminal end attached to anything because when I discovered it, it was laying against the transmission housing and obviously grounding on it. It appears that this negative battery cable is about 4 feet, or 1.3 meters, in length and should attach to the car in two places; is this correct? Where the middle connector is attached to the cable it is bare wire, the connector is clamped on the cable and it was wrapped in electrical tape, the connector is held to the painted surface of the fender well by a bolt. Does this sound like a typical grounding cable configuration?

I am asking because I want to be sure I get a new ground cable that matches the factory config.

Thanks mate - -

TIIsport

Yep, normal configuration for this ground cable - except the end you found floating free should be under one of the bell housing bolts. Mine is under a bolt just below the oil filter, others on this forum seem to prefer a bolt used to hold the starter in place. As long as you make a clean tight connection, either location would be ok. Glad you found the problem.

GTUser

I got all the ground contacts cleaned and reconnected today and reconnected the oil sending unit. I replaced the fried clutch line with a new one from Mazdatrix and took the car out for a much needed drive. I needed the drive, not the car. I idles better now than before the ground short, staying in the 700-800 rpm range, rather than in the 1100+ range. I am a happy guy.

Thanks for the help on this.