15 replies to this topic

[Sorry officer!]

Hi all,
Car is a 988 Mayfair. Standard engine as far as I'm aware.
Basically, the other night I was happily cruising along in a 30 limit and there was a sudden grinding sound from the engine area, I didn't lose power and there was no juddering but it definitely sounded like a metallic grinding sound, not a belt squealing. The noise lasted about 10 seconds and I was about to pull over when it stopped. I took it easy and drove the 2 miles home with no further problems.
Later that evening I went out in the mini again and got about 8 miles from home and had the same problem whilst at traffic lights. This time however the noise didn't go away and the headlights dimmed dramatically. I pulled over and opened the bonnet. It sounded like it was coming from the bottom left of the engine ( starter motor)?
So I switched off because the noise was scaring me. I checked a few connections and tried to restart but the battery was literally dead as can be. Like the lights had been left on all night.

So anyway, I called the AA and the guy put a jump pack on it. The mini burst into life instantly but the noise was still there except it was stopping and starting now. Every time the noise stopped, the headlights would be brighter, then when the noise returned they would dim instantly, Again, the noise was coming from the starter motor area. We switched off the engine and removed the key and were a little surprised when the mini decided it wanted to start again and just started right up. I stalled the engine on purpose and got out only for the mini to start itself again. Only when the jump pack was removed would it stay stopped...

Anyway, what is the noise please guys and why is the battery absolutely fine when the noise is not there but goes almost instantly dead when the noise starts?

I'm thinking the starter is perhaps coming on of its own free will which would explain the noise but would this also draw that much power for the battery to go flat in a matter of seconds?

Thanks in advance.

[sonikk4]

Could be the alternator has failed.

[Sorry officer!]

That did cross my mind but it doesn't explain the grinding noise. I'm going to put a volt meter across the battery to confirm.

[Sorry officer!]

Also, forgot to mention, I fired it up tonight by jump starting off my other car. I disconnected the jump leads immediately once it was started and It started fine and ran sweet for about 15-20 minutes. Then all of a sudden the noise was back and the battery was dead again...

[sonikk4]

The other thing i was thinking was the starter motor has an issue. Its not loose at all? Check out the solenoid as well to make sure there are no issues there with connections etc.

 

Take the starter out and check the ring gear on the fly wheel. 

[Sorry officer!]

It's funny you should say that, the starter motor has always worked fine but the noise does kind of sound like when you forget you've started the car and you try again....
Would the starter really draw so much power from the battery that it would even struggle to run the lights with the engine running though? I'll check it out at the weekend though and see what the state of play is...
I hate intermittent electrical faults!

[sonikk4]

Things do happen although it would be strange for it to drain a battery. It would pay you to take the fan belt of the alternator and it spin it over by hand. You might hear some grinding noises pointing to a failed bearing. If it feels ok and you can get the car started again check the voltage output just so you can eliminate from your issue. 

[Da11yn]

from your description sounds like issue is with the starter motor in that it is staying engaged and drawing draining the battery, this would explain the grinding noise and flat battery. likely cause could be a faulty ignition switch, starter relay or solenoid. 

[Sorry officer!]

Ok cool. I'll have a dig around at the weekend...
Thanks for the input

[Sorry officer!]

Anyone tell me where the starter relay is located? Am I correct in saying the solenoid is attached to the starter?

[Carlos W]

What age is your car?

 

The solenoid is either on the wing or on top of the starter.

 

It sounds to me like a fault which is causing the starter motor to carry on spinning after the car has started.

[Earwax]

water pump bearing can make weird noises, also with alternator bearings,, check for play if not starter motor staying engaged

[Yoda]

You could try starting the car and then pulling the white/red wire from the solenoid. If the problem goes away, then suspect that the start circuit is faulty and will need to be diagnosed. It definitely seems like the starter is pulling in whilst the engine is running.

[Sorry officer!]

Thanks everyone, I've had a trawl through some old threads on here and sounds like the starter re-engaging is the problem. I'll start pulling things off at the weekend if it will stop raining for more than 30 seconds at a time. Annoyingly it seems to be intermittent so I guess I'll just have to leave it idling and wait for the problem to present its self again. The car is a J plate so '91 - '92

[Sorry officer!]

Well, spend a few hours with the multimeter yesterday and couldn't really distinguish a definate problem. However, I did find several loose connections, including the solenoid on the starter. I also can definitely say that the horrible grinding notice was the starter re engaging. I've cleaned and tightened lots of connections and also tidied up the connections on the starter relay as they were quite grim and corroded. It seems to have solved the problem for the minute but it was intermittent in the first place... I'll drive it around locally for a week or two before attempting any long journeys and see how I get on.

Thanks for all the help