10 replies to this topic

[Austin mini 30]

Driving my mates car home last night and it overheated. So i let it cool down, and re-filled it with water to get me back home.

 

So i get home, and my mates are waiting outside the garage for me. So i pull up and one of them wants to sit in the car because he'd never sat in an old mini before. So i let him have a seat ( engine still running) and for some stuipid reason he just plants his foot on the accelerator!! The revs shoot up and hit the maximum for a good 3-5 seconds.  

 

I was extremly annoyed at this. i stopped the car for a bit, and now whenever you go to drive it it will only run on 3 cylinders. Its will not fire on no. 4 (one closest to the flywheel). It drives rough on 3 but will run ok.

 

Has something blown here? it does not overheat anymore, and the oil level is correct with no blue smoke.

 

When i took the (new) spark plug out (no.4) it was wet and oily.

 

Any ideas?

 

The car is a 1977 850cc

[dklawson]

While your friend has angered you, the problem may or may not be of his making.  If this is a high-mileage engine and you have access to a compression tester you should consider carrying out that test first to determine the general condition of the engine, particularly how #4 compares with the other three.  Once you know the engine is generally healthy you can start troubleshooting.

 

Start with the simple things.  Try new spark plug wires.  Change them one at a time so you do not disturb/change the firing order.  Also, replace the spark plugs (all of them... one at a time as with the plug wires) and be sure to gap them before installation.  Do not assume they are gapped for the Mini.  If cylinder #4 begins working again, great.  Keep an eye on its spark plug condition to see if it becomes oily quickly.  If the new plugs and wires do not fix the problem move down the line and replace the dizzy cap and rotor.  

 

If the problem persists with all new ignition parts, or if the plug oil fouls quickly, more in depth troubleshooting of the engine condition is dictated.  However, start with the ignition bits, replacing things one at a time to see if you can address this with the inexpensive parts.

[Yams]

I drove my car with a head gasket blowout between 2 and 3 for a while, drove like someone had thrown a box of nails in the engine but still ran... poorly. It never got hot, didn't burn oil (no blue smoke), but it was obvious something was wrong. Soon as the head gasket was replaced it was sorted. With the symptoms I'd say head gasket is gone and compression is lost in that cylinder.

 

Just make sure you check everything else first like if you're getting spark to that cylinder, just in case. ideally you want to narrow it down to the least amount of variables possible.

 

The oily plug, well that could be a piston ring, a stem seal in the head or if the gasket has badly blown at an oil gallery. Overheating can cause head gaskets to blow out though, but so can red-lining like a knob. Depending on how long it was hot for, and why it overheated is another tin of worms all together but could have been a big contributer to your problem.

Edited by Yams, 01 December 2014 - 01:11 PM.

[Steve220]

Compression test first. If you want to eliminate the plugs, swap it with cylinder one and run the car.

[DannyTip]

These are nice little things for testing you have a spark on that cylinder: http://www.screwfix....pack-of-4/61411

[Austin mini 30]

See if i do a compression test, what is the ideal value the gauge should read?

[sonikk4]

It all depends on the cr of the engine. What you want to see is a set of figures within 10% of each other so for example 160, 155, 160 160. If there is one or two pots reading say 80, 90, 160,160 then that points to an issue on those two pots, normally a head gasket.

[Austin mini 30]

It all depends on the cr of the engine. What you want to see is a set of figures within 10% of each other so for example 160, 155, 160 160. If there is one or two pots reading say 80, 90, 160,160 then that points to an issue on those two pots, normally a head gasket.

Great thankyou. Hopefully get this done asap.

 

cheers

 

Have a great chrismas and new year.

[Austin mini 30]

We'll guys. today i took the rocker cover off and one of the nuts off tappit no. 2 had come off and was bouncing around!! no damage done, set them twice and running better than ever.

 

cheers for your time

[sonikk4]

We'll guys. today i took the rocker cover off and one of the nuts off tappit no. 2 had come off and was bouncing around!! no damage done, set them twice and running better than ever.

 

cheers for your time

 

Happy days, at least it was minimum cost. Have checked the rest of the rocker gear to make sure everything is tight and adjusted correctly.

[Austin mini 30]

 

We'll guys. today i took the rocker cover off and one of the nuts off tappit no. 2 had come off and was bouncing around!! no damage done, set them twice and running better than ever.

 

cheers for your time

 

Happy days, at least it was minimum cost. Have checked the rest of the rocker gear to make sure everything is tight and adjusted correctly.

 

yes I have. running really well now. thanks everyone