Search the Community
Showing results for tags 'it exploded !'.
My 1974 (48 yo) KE30 2 door Rolla has a tow bar, & often gets asked to tow a load of green waste to the local dump. This weekend was such an occasion, & after dropping off the second load, I started the car up, as normal; without issues, & slowly drove out of the dump. As I drove up a slight rise towards the entrance gates, I heard a scratching/grating noise, emanating from under the car. I assumed I had picked some scrap up under the car, that was caught; & was grating on the asphalt. As soon as I exited the dump, I pulled onto the side of the road, left the engine running & quickly looked under the car. Nothing at all ! I then lifted the bonnet, & the engine was still running, but making some strange noises, from what I thought; was it's "inner workings". What could it be ? I have had 4K motors, that with failed timing chain tensioners, or with low oil pressure at idle; resulting in a "stretched" timing chain "slapping" against the inner side of the timing chain cover. However, my 4K-U has a dual chain, so it wasn't that. As I was only 3klms from home, & the trailer was now empty, I decided to head for home slowly, & investigate, once I was in arms reach of a selection of tools. Within 1/2 a klm, the engine started to deteriorate in performance, & a quick look at the voltage reading, on a dash guage; indicted that the battery was about 8-11V, & fluctuating. Eventually, I knew it wasn't going to make it home, so pulled over, turned the engine off, & again lifted the bonnet. Nothing was obvious, so I tried to restart the car. Dead with the battery voltage around 7-8 volt. So a quick call to my wife, She arrives with her 2009 Corolla, & I tow the KE30 + trailer home, as a trio, with firm instructions that She will have to push the brake pedal harder, as there is now no vacuum assistance. My head is now taking in all I have observed in the last hour, & trying to determine what could it be ? I have read & heard of a situation, where a starter motor pinion; will not disengaged after the car starts, & the engine then drives the starter motor at rotational speeds, it was never designed for. Although I had read about this particular scenario, I had never ever experienced it, in all my years with playing, & working with Rollas. As any other possibility, involved internal engine investigation, I decided to remove the starter, as it is an external component, & relatively easy to remove, although not without some fiddling. With starter motor removed, & looking quite normal; with the pinion retracted, I decided to put it in in the bench vice, & power it up, & see if it worked. Here is a good schematic, from the K Series "Yellow Bible". Only difference, with my KE30, is that there is a "starting relay", between the ignition switch, & terminal 50, to prevent the ignition barrel having to handle the high current of the pull -in solenoid. Notice, once the pull-in coil does it's job, & closes the "main contacts" to power the starter motor; those main contacts also s/c the pull-in coil, & the hold-in coil is only left with it's lower current requirement With a 12V battery on the bench, I connected same to the starter motor with some heavy electrical wiring, as you would use with 10-15A power points. I turned to pick up a piece of wire to temporarily active the solenoid, but as I did so, I could smell something, & saw the connecting wires I had just connected, starting to melt their insultation. Grabbed a side cutters, & cut one of the wires. The plot had just thickened, but at least my first guess of the starter motor, being the culprit, looked like it was a reasonable one. To my knowledge, there are basically two types of starter motor arrangement, where the starter motor is a direct drive onto the flywheel ring gear. One type has a scroll on the starter output shaft, so as it initially spins, it "throws the pinion towards the flywheel ring gear", which engages & turns & "cranks" the engine. The second type, which is used in our Corollas, is a solenoid, on top of the starter motor, which via a lever movement, engages the pinion gear with the ring gears on the flywheel. Just as the engagement takes place a large switch on the solenoid, is closed & feeds 12 volts to the starter motor proper. This system is preferred as the lightly spring loaded pinion, will always be engaged before the starter begins rotating. I then remove the starter motor solenoid, & it looks & feels OK. As it needs a big soldering iron, to fully dissemble it, I put it aside, & remove the cap from the end of the now upturned starter in the bench vice. As the cover came off, my eyes were met with devastation like I have never seen before. The internals of the starter motor, had been pulverized, by the starter motor never disengaging from the flywheel ring gear; & being driven at speeds it was never designed for. I suspect, that the contacts at the end of the solenoid, that switch power to the starter, have welded, & not released when the engine started. I'll find out later this afternoon, when I get home, & unsolder the solenoid, & inspect. There are a couple of other suspects like the ignition barrel, where the spring that returns the key switch from "Start", to "Run", has broken. There is also a "start relay', energized by the ignition barrel key start position, that switches power to the starter motor solenoid. However after removing, the starter motor, & finding the above pictured; a quick test with a test light on the output of the starter solenoid relay, indicated these items are both working perfectly. So my question is; is this a problem others have suffered, or heard of, as I have certainly not ever heard of it on these pages in the nearly 20 years I've been enjoying the threads on this forum ? Cheers Banjo