Engine gets too hot

[Pieter]

HI,

I'm afraid my engine is getting a bit too hot sometimes. When I turn the engine off, it switches direction and keeps on running in the wrong direction for a few seconds, until it runs out of petrol. It also makes quite a lot of noise. I'll have another engine in february, but I would like to keep this one working for a few more weeks, as it is my only car.

Wrong direction:
[youtube]http://www.youtube.com/watch?v=OYIa35kw8vI&feature=related[/youtube]

Noise:
[youtube]http://www.youtube.com/watch?v=ZwiBpcHy9kc[/youtube]

Any suggestions?

[ChrisRLewis]

You have what they call "pre-ignition" which can be caused by many things.  First check would be the contact points setting and then the ignition timing.

[Pieter]

I forgot to mention, I checked everything I could imagine already, all I can think about now is something about the head or pistons..
Going to work with it now, wish me luck

[Pete126]

Have you checked for air leaks around the bottom (base) of the carb, a weak mixture can also cause the engine to run on.

[Rusty's Uncle]

I think that I would have a few leaks around the bottom with an engine like that , it sounds like a bag of nails 
It is running oh so very hot so after you cut the ignition the petrol/air mixture drawn in on the induction stroke is being ignited part way through the compression stroke by the sheer heat in the pot hence the running in reverse.
Couple of possibilities , your engine could be posessed by the Devil in which case you might need a priest rather than a mechanic or like I did you have blown your cooling fan at high revs so you ain't got any cooling at all 
Check for air blown out on the thermostat side and for obstructions on the jumbo hose side 

[1973/126]

 Rusty it might be a de ville version, so this would explain it all.

[Pieter]

The fan is fine, checked that one last week Thanks for the suggestions

I haven't checked for any leaks yet

And yes, it sounds like a bag of nails Just made it home from work without any problems!

[GTMaster]

Definitely have to check the timing in this instance. I was wondering what the noise could be in your second video, it could be the cooling fan touching the cowling or maybe even your timing chain is worn (a stretched chain can make a loud noise).

[nrg19uk]

Sounds like the same as mine before I pulled the engine apart and found a bis timing chain on my ac. It had Worn away metal on the timing case and v shaped piece between the sprocket. I would set the timing up go for a drive check again and it would have advanced itself and the more I drove it the worse it would get.

[DEYAN IYI]

Among the other possibilities, could be wrong heat range of the plugs! In your case if you run hotter ones than needed.

This preignition or detonation burning can make nice shaped hols in the pistons.  On other hand that overheating can crack the head between the valves.

PS- less possible, but gas lower than 94 octanes could do the same.

[Pieter]

Sorry for the late reply, winter holiday

The sparkplugs are fine, the timing belt was replaced in april and it's running on 95 or 98 fuel all the time.
The fan is making some strange noises too, but the whole engine now sounds like it died two years ago. I'm going to replace the whole engine.

[youtube]http://www.youtube.com/watch?v=qyWRuQmahAI[/youtube]

[DEYAN IYI]

Hi and happy new year!

Your motor is still alive   Do not kill him violently!  

You said that the ignition is fine, but the effort to start and the sound later reminds me to mine when was trying to run with ... 20 degrees ignition delay   Anyway...

I noticed something to wary about look the video after the 2min. The pump is making the fuel in bubbles, then when you twist the throttle even worse - it turns to foam Probably there is problem with the non-return valves. Check also the lift of the pushrod.





Here is something I've written before on this subject:

Try the non-return valves. When you suck through the inlet pipe, and blow through the outlet one (covering the pipe for the return fuel) shouldn't pass any air. If there is a leak, skim the contact surface on wet sandpaper (on something flat, table for example), but only turning, not sliding. On the picture to the left is done. If the "brown thing" is worn out (like the upper left one) just turn it round.
  
 

[Pieter]

Thanks for the reply, happy new year to you too
I'll check those one of the days, when I find the time. I started it earlier today and it took about a second or something to start I think there is something wrong with the choke also. Strange thing is that it drives normal. I did a 0 - 100kmph in 57 seconds today, normal acceleration and so on. For now I'll just try to find a way to get my second engine here, as it is in Poland now, in my other 126 ;-) I'm going to swap the whole engine and gearbox, as that only takes a few hours. This engine will be rebuilt in summer, I should have time then

[Darrell]

Unless there is a bad knocking noise or huge amounts of smoke, I wouldn't change the engine. The noise is coming from somewhere and the timing needs to be done with a timing light.
Mine overheated alot at one stage and there is a long thread about this as I would not give-up till the problem was solved and it turned out to be a faulty electronic ignition part I had bought to replace my points.

The camera will amplify the noises and 126's always do sound like a bag of spanners after a while, a little TLC and checing valve clearances etc and it'll be good for another 20000 miles.
I'd buy that engine from you now if you were closer

[Pieter]

Actually it sounds better on the video than in real life
There is also quite some oil in the air filter, and I have to refill the oil every 500km now.