MGB Slight starter motor noise

[busybrit]

Came across a situation today that I'd like an opinion on.

The MGB I was working on starts ok but there is a slight noise "most, but not all" of the time you try and start it, it sounds as if the starter is having a very slight difficulty trying to mesh straight away with the ring gear. It always starts with out an issue. When I momentarily supply direct power to the lead going to the solenoid from the battery terminal on the starter, or from any other live point say the fuse box, the starter engages straight away and there is no grind, "if you could call it that", or hesitation.
The starter is new as is the starter relay.

So, for now it's on a push starter button with out any issues. Any ideas as what could be causing this???

Thx

 

[Mickey Richaud]

It sounds like by bypassing the ignition switch, you've cured the issue. So I'd suspect the switch.

Let us know how you get on, please.


Mickey

 

[PAUL161]

I think Mickey got it right. The start switch is ready to be cleaned internally. It's giving spasmodic contact and probably arcing inside. Clean it and put dielectric grease on it. OR, you have a bad bullet connector in line, but that usually means no contact at all. PJ

 

[WillR]

If I remember correctly I had to put a push button on my starter because sometimes it worked and sometimes it did not. NO funny noises though. Just did or did not. My starter was old and a new one fixed my issue. Though after that when I used my E brake the starter would kick on. It sounds like the above posts are more up your ally though. Man the curve balls these cars are able to throw.

 

[Sarastro]

It's common that, as the ignition switch wears out, the contacts get burned and dirty. Then, they lose contact briefly as you turn the key. The result is that the starter solenoid loses power for a very short time, often not enough for the starter to disengage completely. That sounds like what you're experiencing.

The solution is a new ignition switch. You might also try installing a relay to operate the starter solenoid. That seems a little strange, using a relay to operate a relay that operates the starter, but by reducing the current in the ignition switch it might work.

 

[aeronca65t]

I would say high resistance in the internal contact points of the solenoid (that's why when you "jump" past it, things sound better).

I've taken an old solenoid apart to clean the contacts (not sure if that is possible on the newer, Chinese units). Adding some dielectric grease is a good idea.


As Will says, some of the older solenoids have a manual "button" on them (but most do not).

Also, check the connections of the heavy wires. Sometimes, even if the nuts are tight, there can be corrosion that makes for a poor contact.

Unless you have one of the newer, gear-reduction starters, your solenoid should look something like this: