Misfire at idle

Hi all.

Tech question for ya all.

My little beast has developed a misfire at idle. Its also got bubbly/foamy coolant coming out of expansion tank. Not a lot of it though. It only misfire once warm, and when i pick rev up it stops.

Now i fear head gasket but though id run it past everyone first.

Any input very gratefully received.

Many thanks in advance.

Bazza.

what engine do you have

Ah ha. Bugger not sure off top off me head. Is it stamped on the block somewhere?

Typical me not prepared at all!!!

does it have a cam belt or timing chain single or double over head cam has it a black plastic top covering the spark plugs or are the plug to one side of the rocker cover

Sorry mate. Its single cam, cam belt. 16 valve. And there is no cover over plugs they straight in rocker cover.

Not sure if this will help.



Many thanks.
Bazza.

I say any thoughts chaps??

If there's something weird going on with your coolants, it's probably blown head gasket. But that's easily and cheaply fixed if you know your way around engines. G13 engines are easy to work with.

I would first run some compression tests, before doing anything else.

Lovely job thank you mate. appreciate that. Got a friend popping scanner on it tomorrow see if any faults logged. Its running bit rich by smells of it.

Am very happy working on it. Trained as Renault tech few years ago. So will be doing it myself.

Good to know what engine it is, thank you.

Sorry all. Just being a pain now!!!

Got in car tonight to go home from work. It got hot as hell almost straight away. I stopped and rad was empty. Can't see any leaks and there is no trace in oil. There was fair amount in expansion tank.

Noticed on rad cap that bit seemed loose. On pic below its the small disc that's hanging down is completely loose. Didn't know if this was normal??



AAHHHH HELP.

There look to be rubber seals missing.
The cap seals down onto the flange in the radiator with the big ring. When the radiator water expands, this lifts up and lets the extra into the expansion tank.

When it cools down, the little loose middle part sucks down and lets the water back in, this part blows upwards with pressure, and has a rubber seal on the top.

I tried to recreate your picture with mine



I suppose yours could be a different design: is the expansion tank cap a plain flip top or a pressure cap that unscrews?

(Still sounds like the head gasket has gone though )

facade wrote: There look to be rubber seals missing.
The cap seals down onto the flange in the radiator with the big ring. When the radiator water expands, this lifts up and lets the extra into the expansion tank.

When it cools down, the little loose middle part sucks down and lets the water back in, this part blows upwards with pressure, and has a rubber seal on the top.

I tried to recreate your picture with mine

I suppose yours could be a different design: is the expansion tank cap a plain flip top or a pressure cap that unscrews?

You have made a far better job with ya picture. Expansion tank lid just pushes on similar to a washer bottle.

Well had head off Saturday folks and gasket on exhaust side on no 1 had pretty much perished. Coolant had been flying into chamber. I've done heads on most renaults and several fords and vw. But what a faff the Jimny was, take the bloody cam shaft out!!! Still i suppose it can only be good thing makes u do valve clearances. And boy is there plenty of room under there.

All.done and runs like a dream now. Thank you all so much for input and advice very grateful.

Bazza.