Old R11 1.1 pushrod engine problems

[nametooshort]

So, I bought myself a 80s pug 305, and my friend decided that they also wanted a beat-up 80s French car, so they bought a Renault 11.

It's an absolute bottom-spec base model, and it has the 1.1 pushrod engine. At first we thought there was something wrong with it, since it was somewhat slow, but it seems that's normal for when you try to power a not-so-small car with a 50hp engine.

My friend is not quiet as used to classic/old cars as me, so the whole maintenance thing is reasonably new to them, iv been helping them out.

When they bought the car, it had a split heater hose, one of the hoses came off it's clip and rubbed on the hot exhaust manifold and sprung a leak. Being a low-spec model, and therefore only having a 'your engine cooked about 2 minutes ago' lamp instead of a temperature gage, he ran it a while before the light came on and he realized it lost coolant.

He asked me to help out so I found the broken hose, replaced it, and also found that the water pump was worn badly, of course all the bolts snapped off but managed to extract them all without issues and all is well now. I suggested he should also give it a service, since who knows when it last had one.

The thing that puzzled me is that the spark plugs that came out of 3 and 4 smelled funny. Their tips had a very very strong pungent sweet/chemical type smell. I have never encountered this before. The spark plug in no4 was also slightly melted around it's edge! All the plugs looked somewhat black, so it was slightly rich, however an old carburetor car with lots of short journeys often doesn't have ideal sand-colored plugs, they were not badly sooted up or anything.

However, the engine is not showing any signs of problems. It doesn't seem to use coolant (but then again it hasn't ran much since then, this was only today), doesn't spit coolant/steam out of the exhaust, doesn't bubble through the coolant, doesn't overheat now that the leak is fixed, and seems to run fine.

I assume the really sweet chemical smell on the spark plug tips is from antifreeze burning in that cylinder? So i suspect that perhaps overheating it with the broken hose may have mildly popped the head gasket or cracked the head?

But the melted spark plug thing is very odd. It's not like totally melted, but the edges of it are. As far as I know, if an engine gets hot enough to melt the edges of the spark plug, then the engine is totally totally 100% deeeead, however this one still seems to run OK and is not showing too many signs of distress.

Anybody know these engines well? Any ideas? Do they normally blow head gaskets if they get hot enough for the lamp to come on? Anybody know about the odd sweet smelling spark plugs?

Thanks!

[lexi]

Could be a very slight water issue in the plug. Plugs can also go very hot if not torqued down or loose in head. Some of these old heads use to crack between plug holes.

I would do a compression test on it. Cylinders should all be within 10% of each other and the closer to the given figures (should you obtain them) the better .
The good news is that it aint much problem to whip the head off on an engine like that and have it pressure tested. Does it have hardened exhaust seats for unleaded fuel?

All depends how far you want to go on your classic.