Please help! Renault Laguna II

Hello guys,

i have a problem with my Renault Laguna II, 2007, 1.6. 16V. It has 142.000 km on it. Here is the issue:
When I leave the car sit of around 8 hours and when I then turn it on, it sounds like it runs on 3 cylinders (car also shakes a little), like a tractor. The RPM’s in idle go from 1200 to 700 about 5 times (sometimes more, sometimes les) and after about 20 20 seconds they stay at about 900. When it’s doing that I can smell gas from the exaust. Also for the first few minutes of driving the car has problem accelerating from 1600 RPM’s or lower. It starts shaking and hesitates until it reaches about 1800 RPM’s and then it goes smooth.

Before I had the fuel injectors changed, the orange engine light came on when i drove up a hill immediately after starting the car. My mechanic said, that it was a code for to much fuel in exaust.

I had all four fuel injectors changed, all four spark plugs, Also I had the ignition coils checked and one of them was changed. Please help me find what could be the problem.

Thank you all for reading my problem and I for giving their opinion.

Have a nice day ahead.

Is that orange engine light still on?

Given what has been changed, it would be smart to have a compression test run to see if one cylinder is low.

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Is it possible that this is the problem? Because after a few minutes of driving the car is as good as new.

Out here on the internet without data, who knows? That’s why it is called a compression test

Again I ask… Is the orange engine light on?? (More data)

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No, the engine light started to flicker until i got on a flat terrain and then it went off. Since i had these things that i mention changed it didn’t come on ever again. Before i lost the full power of the motor, but after changing these things it doesnt accelerate up the hill, it is barely strong enough to get up it in the second gear.

Thank you for your help.

Then take it back to your mechanic and tell them what you are experiencing. The pre-repair symptoms were addressed by replacing injectors, plugs and the coil.

Now the symptom is low power with no engine light

I suspect the mechanic will run a compression test and there likely will be low cylinders. The solution for that would be a new (or good used) engine. Not a cheap repair.

Ok, I will tell him to run a compression test. I don’t have the money for a new engine. Im a student and I really cant afford this. Hope this won’t be needed.

I once saw a car with this symptom.
It was coolant seeping through the head gasket.

Pull the plugs after the engine has sat cold and see if any are wet.
Is there a slow loss of coolant?

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I agree with @circuitsmith. I had the same symptoms with a 1990 Ford Aerostar I once owned. In my case, there was a crack in a cylinder head that let coolant seep into a cylinder.
A defective head gasket could cause the same problem.

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Thank you so much guys :slight_smile: Will talk with my mechanich about this. I really appreciate the help :slight_smile:

You may have a bad coolant temperature sensor.

My mechanic said he measured it and it is ok

If the compression is low, you can just live with the lack of power. Or…I would try adding a can of Restore, or similar oil additive, to see if that helps. It isn’t expensive and might last you to graduation.

This sounds like a head gasket leaking compression until the engine has warmed up. If this engine uses a composite head gasket, it may have worn out due to thermal cycling. If so, the problem is not going to improve on its own.

That’s good advice, but that product might not be sold in the country where the OP resides. Or, it might be sold under a different name.
:thinking:

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Symptoms (including too much gasoline in exhaust) are consistent w/intermittent misfire. Misfire causes (typical)

  • No or weak spark
  • Fuel system problem
  • Major engine mechanical problem (such as inadequate compression)

No experience with this particular car, just guessing, but if I had the same problem on my Corolla I’d focus on the spark issue first. Ask shop to test for a robust, healthy spark at all 4 spark plugs, when the problem is occurring.

In addition, sensors tell the computer how to set the fuel mixture. If you have one or more out of whack, it can be commanding the computer to provide a too rich mixture. A diagnostics computer can see what the sensors are providing to the computer at the hands of a good mechanic. O2, maf, air sensor, temp sensor, etc. like I said before, in a million plus miles I have never had a bad injector.

I can’t say I’ve ever definitely ID’d a bad injector on either of my 2 fuel injected vehicles in 40+ years, but I did have a drivability problem on my Corolla that a couple of doses of fuel injector cleaner fixed. I’m guess such a thing is possible. Just a guess.