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MG MGB Technical - Strange engine trouble - where to start?

My wife had the MGA out today (it has a 3-main 1800 B engine). This is her description of what happened:

Driving along on the freeway around 65MPH.
Car sputtered like it was out of gas.
Engine died, she pulled to the side of the road.
Temperature normal, around 215F
Oil pressure around 25 while sputtering (unknown before sputtering)
After stopping, she pulled the starter and nothing happened - completely dead.

She also said there was a small pool of oil under the car. It always leaks more than normal but it seems there was more than there should have been so quickly. A flatbed tow truck came and loaded the car. When they got it home, there was oil and coolant on his truck. The guy looked in the engine bay and under the car and couldn't find any leaks or where any fluids came out.

When I got home I looked and found nothing as well. So I turned the key, pulled the starter and vroom! It started right up and purred like a kitten even while reving.

The only thingout of the ordinary lately has been valve noise. They are adjusted perfectly (I've checked twice with conventional and with Click Adjust) but they seem really noisy. Is this a symptom? I'm completely stumped at where to start or what could cause all this. Suggestions?
Steve Simmons

Forgot to mention when I started it in the garage the oil pressure was perfect, around 60 at idle, 65-70 reving.
Steve Simmons

Steve,

It sounds like a head gasket failure.
Have you done the usual checks of; the oil on the dipstick being a creamy white, air bubbles appearing in the radiator water when running (do not confuse with water surge caused by the pump), and a compression check?

Mick
M F Anderson

The dipstick looked perfect and it's full of oil so it couldn't have been too much, perhaps half a quart. Strange thing is that the car runs fine in the garage.

What still gets me is the starter button not doing anything. She said it was as if it wasn't connected. The battery did die a while back after driving with the lights on for an hour. I charged it back up and it's been fine. Come to think of it the headlights have always been a bit dim as well. Voltage seemed fine at the dynamo, the battery and the regulator. Perhaps an electrical bug killed the car for a short time until it cooled?
Steve Simmons

This is strange, have you filled the gearbox recently? that might explain the oil, the radiator, is it a standard A version, that might explain the coolant. And it might be just a dodgy connection on the starter switch, where the supply to the regulator and starter come together.
Tatty

Steve - similar thing happened to my 67 BGT recently - started to splutter, died and would not start again. Not sure what it's like on the MGA, but there are a couple of major fuse connections on the inside of the front wing - one of which feeds power to the fuel pump, fuel guage, wipers and heater. There was a small break in the wire which had, at some point in the journey, caused the petrol feed to cut out - so, after the fuel had been used from the pipeline, the car began to stall - as the engine wanted to die, the oil pressure went with it. Quick wobble of the wires made everything work again so I could get home. Sorry - doesn't explain the oil and coolant though ...
martin

Steve,
I once had a freeze plug leak occasionally. It happened to be one right bu=y the distributor. Why not give those a check, that is the ones you can see.
Dave
David Steverson

Steve.
Start with the batteries.
Check for voltage with the engine off.
If it's below 12 volts, then that could be the cause. Most cars will even start with 11 volts.
Once you start the engine, it should rise to 13.5 to 14.5 volts.
The dynamo will keep a car running if it is charging, even with a dead battery. But consequently, if it's not charging, then the car will die when the voltage drops below where the need to run the ignition and fuel pump, radio, lights, etc.
Are the batteries dead? Then charge it up for at least 3-4 hours, up to 8 hours at a low charge rate.
Voltage should be in the 12.5 to 14 volt range. Then start the engine and run the revs up to about 2500 rpm.
It should be in that 13-14 volt range.
Turn on all accessories, and it should not drop below 12 volts.
Remember, batteries will recover a bit just sitting, if it's not too cold out.
Safety Fast
Dwight
Dwight McCullough

Completely dead is an electrical problem, leaking fluids is something else. I can understand an electrical problem correcting itself, less so leaks unless only when hot. Maybe she just happened to stop over someone else's leaks (and on the breakdown truck), I always look on the ground as I pull in to a parking space, more than once I have walked back to the car and spied fluids on the ground, only to discover they weren't mine. Bad charging and a flat battery wouldn't have allowed it to start back home without a recharge. Valve noise is normal to a great extent, but I have found that the greatest gap on mine isn't at the strict 'rule of nine' point if that is what you use, but slightly before or after dpending on the valve. Adjusting them at the 'biggest gap' position makes them quieter, but not quiet.
Paul Hunt

Yes it's all strange. The only thing that perplexes me is the dead starter switch. THe connections look fine. All these symptoms don't really belong together. I also suspect some of the claims she made since she's not very car savvy. I interrogated her last night and by the end she admitted that she may not be able to really tell the difference between cooland and oil on black asphault. So it's possible it was just coolant bubbling over from stopping cold after driving at high speed. And she also said it's possible she simply couldn't hear the engine turning over because the freeway traffic was very loud, but it's unlikely she wouldn't feel the car shaking as the engine turned. In any case I'll double check the electrical system tonight to the best of my limited ability. Thanks for the input. Every suggestion helps! :)
Steve Simmons

Steve,
The car just dying like that makes me think fuel pump connection. My B died on me one day , fortunately in very nice neighborhood, so I borrowed a flashlight (left mine at home) and looked under car. The white hot wire had come loose. I had noticed that intermittently the car would sputter so I believe it was kind of partially connected for a long time then finally came loose. If not at the pump, perhaps somewhere else in the ciruit. My sympton was that it would crank but not start as I was getting no fuel. Certainly sounds electrical to me too so I would go there first. Easy for me to say. P. Hunt said it first!
J.T. Bamford

Have a look at the brown and white wires at the ignition switch. If a connector is corroded, it will do exactly as you describe. As the car demands current, the connection heats up, becoming more and more resistive, until it just can't pass enough current to operate all the systems running through it, and the car dies. After it cools enough, it works again.
Ken Lessig

"I interrogated her last night and by the end she admitted "

I suggest that is not a good idea.
Edd Weninger

Perhaps I should reword that line. Where's the "edit" button anyway? :/
Steve Simmons

This being a B group some of the responders may not know how the starter in an A is activated. Check the ignition last, if your A is anything like my 59 your wife would feel it cranking no matter how loud the freeway was.Sounds like poor conections at the battery/starter system and yes poor conections can be intermitant. Ric
Ric

Steve. If you have not been able to find the problem, you need to drive the car until the problem comes up again. As has been pointed out, the problems you describe do not make sense. If you, as a more experienced driver, and duplicate the problem, it would be much easier to solve.

On my MGA, there is not a "button", but a pull switch. This can take a bit of pulling, especially as the contacts become a little corroded or burned. We may be looking at a difference in physical strength here. The wife not being able to pull hard enough, but you can, might indicate that the solenoid is marginal and getting ready to go out. Of no real value, but worth considering. Les
Les Bengtson

I haven't had a chance to take the car out yet but will do so this weekend. I'm going to try and duplicate the problem but hopefully not on the freeway!

I did say button but I meant pull switch. I just couldn't think of what to call it at the moment I wrote that post. :) My starter isn't very difficult to pull so I doubt she didn't pull it enough. And as Ric says, she should have been able to feel it cranking. I'll update you all of my findings if I actually find anything!
Steve Simmons

This thread was discussed between 25/07/2003 and 26/07/2003

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