Car doesn't stop....!?

toyota
corolla

#1

1999 Corolla.



Has had starting difficulties for 2 months.



Yesterday I turned my car on. It made a strange noise the whole time it ran (I only dared drive it to the end of the block). When I turned it off (and pulled the key out), it made another weird noise, like it was still trying to do something with the engine, for another 30-35 seconds.



I was afraid it wouldn’t stop at all, as it gave no indication it would until it finally just quit.


#2

There may be something wrong with the starter solenoid. These can fail where the starter engages when the ignition is turned to start, but the starter continues to run after the ignition switch is allowed to move the run position. Does this sound like what might be happening?

Tester


#3

Yes, actually it sounded a lot like the car might have been trying to restart itself.

However, does this explain the weird noises while the car was running? Could I have two different issues going on here at once?


#4

The weird noise while it was running could very well have been the starter still engaged and running while the engine was running.


#5

Excellent. Now I just need to know how to fix it. I found a place that can replace the whole starter for 350, but it sounds like it’s just the solenoid. Is the starter solenoid different than the starter relay (some places make them sound to be synonyms, others make it sound like a car has both)?

I followed the red positive lead from the battery and found a fuse box, one fuse in there was labeled “starter relay.” Is this the relay itself, or a fuse to the relay? Can I simply go to a junk yard and swap this part out?


#6

That’s the relay. The solenoid is built into the starter motor assembly.

When you turn the key to “start”, the circuit through the starter relay solenoid (NOT the starter solenoid) is completed. Contacts in the relay close enabling the starter solenoid winding circuit. The starter solenoid slides a lever that (1) engages the starter motor gear to the flywheel ring gear and (2) closes contacts that complete the circuit to the starter motor windings. Once the engine starts, the flywheel ringgear begins traveling faster than the starter motor gear. That mechanical action, that “backward loading of the starter gear”, mechanically moves the starter gear out of contact with the flywheel ring gear and opens the starter motor contacts.

This whole lever system is commonly known as the “Bendix assembly”.

It is possible that if the bendix assembly is mechanically malfunctioning such that the starter motor is not disengaged by the backward loading of the starter gear, the motor will stay engaged and the engine will overpower the motor, forcing it to spin at high speed as you drive. Yes, this can happen.

The only fix for this is to change the starter motor assembly.

I hope this helps.


#7

Sounds like a classic case of fouled plugs to me. Poor starting and running after the engine is turned off is what I got out of the post. Pardon my senile brain but is it pre ignition when carbon buildup causes running after turned off? seems like it should be post ignition :wink:


#8

you should have it checked out by a competent mechanic. AND dont run it. If the starter has been ‘hanging up’ and is still engaged there is likely damage to 1. the starter. 2. the Flywheel, and 3. the flywheel teeth.

at this age car, if there is huge damage it is probably not worth fixing. but before you continue to run the car and ensure damage, STOP running it and adding to the possibility of lunching the engine. This could be a simple starter replacement and you’re good to go for another 100,000 miles.


#9

Can cars with fuel injection run-on once the ignition is turned off? They could back when cars had carbs because fuel could still flow. Is dieseling, or run-on, still possible? I don’t think so but I’m not sure.

The starter problem sounds more likely.


#10

FI cars don’t suffer from dieseling (run-on) because all fuel flow is stopped when the key is turned off. I think that the OP’s description is wrong and that the starter or engine fan is continuing to run, not the engine.


#11

At this point I’m inclined to stick with the starter assembly theory.

As Tardis pointed out, fuel injected cars don’t diesel becaue the injectors close when the power is shut off. No fuel, no ignition.

A stuck Bendix assembly could keep the contacts to the starter motor engaged, keeping voltage to the starter and creating that sensation that it wanted to keep running, even without fuel. It could also be the source of the strange noise while in operation. It could also have unstuck after that 30-35 seconds of being in the “start” position.

But I really think this vehicle needs to be looked at and listened to. I’m basing my guess on the very little information provided in the post. It isn’t the OP’s fault, he/she is doing his/her best to describe it. It just isn’t clear enough to guess without making some assumptions.


#12

bet all it needs is a simple tune up


#13

4 stars for you as that was similar to my thought, being as a tune up includes new plugs, sure it is the simplest and least expensive answer, but then there is the need to find why, if there is one, gosh how many miles since the last plugs?


#14

I don’t see how a tune up could solve a problem with the starter staying on?


#15

It just seems more probable than the starter motor being engaged from start to finish. I find it improbable to have a starter motor engaged all that time, and it does not explain the poor start.


#16

The problem with the tuneup theory is that it won’t cause dieseling…

Carburated cars can diesel after the key is removed because the gas is pulled into the throat of the carb by the vacuum of the pistons pulling air into the chambers. It’s pulled from the carb’s float bowl. This can go on until the level in the float bowl goes too low for the vacuum to pull any out. If there’s sufficient residual heat in the chamber when the piston pulls the fuel in, it can ignite. Carbon is great at retaining heat. That works great for charcoal briquettes, which are carbon, but can if built up in a cylinder (and when combined with the heat generated from compression) prvide enough residual heat in a chamber to ignite the fuel.

In the very early '70s, when manufacurers raised operating temps and leaned out the mix (raising cylinder temps) to try to reduce emissions, this was a common and chronic problem. They added a device called an “idle stop solenoid” to completely close the throttle plate and choke off the engine, preventing dieseling.

But fuel injection systems operate by a needle valve being opened by the ECU signal and spraying fuel under pressure from the pump. When electricity is removed by turning the key off, the valves go to their deenergized position, which is closed. There is no longer a fuel supply. Vacuum cannot pull fuel in. Fuel injected engines simply cannot diesel.

The hung up starter motor, while not common, is not unheard of. I does occasionally happen.


#17

careful re reading of the OP states TWO different topics.

  1. car had hard time starting for 2 months. So Yes a tune up may be required.

but

  1. ‘strange noise’ while on, and after ‘key off’ foor a few seconds. This indicates another issue, which sounds like a hung up bendix. (or maybe a chewed up flywheel chewing on a flywheel housing or cover plate until it stopped turning)

#18

Happened to my 1999 Corolla today. Certain we are not discussing engine run-on. I have been having “starting problems” by way of cold-start hiccups on the first turn of the key. The starter fails at first try much like symtoms of a weak battery. Second try it starts right up. Replaced battery without testing thinking I might get stuck on a low charge. Did not solve the problem.

This morning the starter engaged and started the gas engine but did not disengage. So I had both the engine and the DC motor running. I turned the ignition key fully off. The gas engine stopped but the starter motor continued. Jiggled the key, no effect. Turned the key to “on” and the gas engine restarted. Turned off the engine but the starter continued.

I scrambled to disconnect the battery terminal and finally silence. Two times I reconnected the lead and the starter engaged and ran. After a short while I reconnected and short clunk but the starter was out of the circuit. I started fine and got me going.

Problem is likely the solenoid which is connected to the starter which I learn is a little tricky to get to on my 1999 Corolla.