Hey fellas, got a problem with the wife's car.

I know it's not a bike problem, but I figured this is the saloon and we can discuss what we like as long as we're buying the beers eh?

The car is a Renault Scenic 1.4 with about 50,000 miles on the clock.

When it's cold it feels like it's running on 3 cylinders. We took it to the garage to have it looked at and they said it's got an oil leak, through the cylinder head gasket into one of the cylinders.

The thing is when I changed the spark plugs recently, there was no sign of oil on any of them, in fact they all looked fine. Surely if one cylinder was burning oil, the spark plug would be all fouled-up with black oily deposits?

What do you guys think?

 

I would certainly think the plug would look different. As for the 3cyl firing when cold... that could be so many things. All you can really do is try and troubleshoot while it's cold. Fuel/fire. Does it smoke?

 

I would think one of the plugs would have burnt oil residue on it and it would smoke if its burning oil, have you noticed it getting low on oil? I would pull the plugs out again one by one and check it out also put a compression test to each cylinder, you can get a cheap tester at harbor freight.

 

It's been doing this for a while now and as mentioned I changed the plugs when I did a service about a month ago. All the plugs were as clean as a whistle, no water in the oil. Thanks for the answers though lads, just wanted a second opinion.

 

Is it throwing any trouble codes? I'm not really familiar with renault, but it's a car right? Hehe.. I'm kidding.

Anyway.... I've seen similar issues with bad ECTs (coolant temp sensors). You'll get really hard starts when cold with hesitation and the car dieing. I've seen this on a few cars.
What happens is that the sensor thinks the car is warm so the ecu throws off the fuel mix to the lean side. It can happen the other way, too...... Car won't start when warm because the sensor thinks it's cold and chokes the **** out of it. You can tell because it will usually start with full throttle when hot (leans out the mix).

It could also be a cam or crank sensor. Sometimes they go whacky when cold as well.

Then again, it could also be ignition related. I've seen plug wires and coils act funny hot or cold.

Any more info? What are the exact symptoms? Does it start right up, but just hesitate?

 

Bad Coil Pack on that chamber Hawk ..... garage is talking shyte ..... had a similar issue
with the Volvo Coil Packs on my own car

You'll know the bad one when you pull 'em one by one by sound

32 quid a set on Ebay

 

Ignition wire - possibly cracked insulation or fracture in the wire itself ?
I'd be more inclined to that than an oil leak.

 

Could very well be, which is why I mentioned it. Could be something else, tho.

Funny story with a coil on a toyota once. Had a bad miss at high rpms in the heat. Beat my head against the wall for like 2hrs trying to figure it out.
I was thinking really hard....leaned against the truck... hand on the fender... and got the living $hit shocked out of me.
Replaced the wire and all was well. lol...

 

Thanks again for the replies guys.

Drove the car again today.

Starts on the button but uneven idle/flutter from the exhaust, seems to fire on three under load until warm around town.

On the freeway/motorway gets a slight miss fire especially uphill.

Once I get the bike back together completely and thrash the hell out of her I'll take a look at what you've all suggested, got a list of ''to do'' things as long as my arm!!

 

Hey hawkwind, your last reply makes the issue sound very electrically based, such as a dud ignition lead, cracked dizzy cap or rotor, possibly even a dodgy plug. Cheers