Morris Minor Owners Club

Hi, just wondering if you can help me. I did an oil change/ail filter/spark plugs the other week. When doing the oil change I drained the oil, then topped up with fresh. However as it turns out I don't think all the oil could have come out, maybe it was a bit sludgy at the bottom because I only put in about 2.5 litres and it was reading above the FULL line on the dip stick. However I needed to get home and from where I did it, so I drove 10 mins down the road. The car didn't really sound very good at all!

So a couple of days later after letting her rest in the garage, I drained the oil again, (5 litres came out)! I put in a good quality oil (to the right level this time), replaced with a fresh oil filter. However there still seems to be a problem. Whenever I stop at roundabouts or in traffic I have to pull the choke out to stop it from stalling, even though the car is warm and I've been driving it for a while. Another thing it has also done since all this is when I take my foot of the accelerator, it makes a hissing, tapping noise!!

Any thoughts would be much appreciated.

LUKE

First thought about poor running is that the plug leads might be in the wrong order, or that one (or more) of the new plugs is not as good as it should be. Check the plug gaps. Try putting the old ones back in. Double check the firing order.

When changing the air filter, did you disturb any breather hoses or the choke cable? Did you try to tune the carb?

If the oil level was REALLY high then that could cause running problems, but it would have to be really overfilled to have a serious effect. If that was the case then there is a possibility of excess crank case pressure.

Did you also do points at the same time? Timing could be a problem. Hissing noices can be various things - head gasket, radiator related, carb. Is the new air filter fitted properly?

Could you clarify what engine we're talking about - 1098, 948, 803, etc.

Did you get the engine warm before doing the oil change? This is the recommended way but shouldn't make that much difference.

Also if you changed the oil filter,always a good plan, it will take a pint or so to fill it so always worth rechecking to oil level after the first run.

Another thing to bear in mind is that if the drain plug isn't the lowest point when you drain the oil then it won't all come out, hot or cold.

I agree with above - check the spark plug leads are on the correct oder 1342 anticlockwise around the dizzy cap.

Thanks guys. When i did it i did one a a time to make sure that i didn't get them in the wrong order. However i think you might be right about the plugs gaps. I did them at .25. Is that right? With the problem I've got is it likely to be the gap I've done is too big or too small? Thanks!

Well - what is " .25 " ??? Doesn't make any sense to me ? Is that .25 of an inch? In which case FAR too large - or .25 of a Millimetre? - In which case far too small. The correct gap is 25 thousandths of an inch = 0.025 " . But if you are sure the plug leads are correct order - then indeed I was going to suggest a 'bad plug' - why not just refit the old ones and try that ? What make are the new plugs ?

As a rough guide the gap is about the width of a bit of fag packet, cereal packet should work for non smokers .

Ok I'll try that. I did do it to 0.025. Maybe I'll check them again though. I bought the plugs from Bull Motif. Don't know the make, and threw the old ones away!!

Thanks, I'll be using a cereal packet!

Luke

Use a feeler gauge - and never throw away old plugs - always carry a known good set with you.

Was it running fine beforehand, and did you replace anything else apart from the plugs ?

Back to the hissing sound upon lifting off the accelerator: is it possible that you dislodged a vacuum line/plug in your tune-up efforts? That might also account for poor running...

Hi, thanks for advice guys, I'll check nothing has been displaced. I replaced all four plugs, air filter, oil filter, and rotor arm. The car was running really well before I did all this!

I notice that there is no mention of changing or checking the points, 0.015 gap. No need to change the rotor arm if the engine is running ok

Put the old rotor arm back on.........

Why would an old rotor arm be better than a new one? Would that make the car stall?!!

Many of the new rotor arms are complete rubbish - endless problems with them........ It's a two minute job to try it!

There are some poor quality new rotor arms around, search for previous threads. Old rotor arms are more reliable so leave them alone

There are some poor quality new rotor arms around, search for previous threads. Old rotor arms are more reliable so leave them alone

There are somme poor quality new rotor arms around, old ones are more reliable. If it works leave it

It's always a good plan to try the cheap, easy fixes first.
A complete new distributor would fix it, but would be more work and more money.

Not everything new is good, especially when the pressure is on to produce parts more cheaply.