bad spark plug
- Thread starter killing_time
- Start date
Jon_G
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I'd say it's running a bit rich... did all 4 look the same?
Well the spark plug is definitely fouled - it is the correct type of plug for your car? For the 2.4 they need to be Iridium.
As Jon has said, it looks like the combustion mixture is running rich, but with PGM-FI it's difficult for the car to run rich unless there's a sensor off.
killing_time
Members
No, only this one spark plug. I'm running on LPG, and i had problem with lambda sensor.
killing_time
Members
Yes it's iridium, NGK IZFR6K11. I have replaced all 4 of them now.
Is this on cylinder 2? If you replace this spark plug only, perhaps it's not secure correctly, etc.
killing_time
Members
It's on cylinder 1, from the right.
From the right? As it nearest the timing chain or clutch?
Reason I ask is cylinder 2 runs hotter in these engines, but the plug doesn't look burnt. Since you've replaced all sparks does the new spark plug appear to be fouling? Since you're running LPG could it be a leaky injector?
killing_time
Members
Nearest to the clutch. Could it be bad piston rings, or cylinder?
Ok, that's cylinder 4. The plug looks "wet" with oil and other carbon deposits. Yes, it could be piston rings, but the only way to confirm this would to do a compression test to see if you are losing pressure. Let's start with the simple things. Are you buring oil?
killing_time
Members
Yes car is burning oil. 1l on 500miles....
Ok, then that would explain that the fouling
So it looks like oil is leaking into cylinder 4 and get caught up in the combustion cycle leading to the fouling of the plug. Now, it could be any of the following:
1. Valve Seals
2. Piston Rings
3. Cylinder Bore lining
4. Piston itself
Anyhow, you'll need to get a compression test done on Cylinder 4 to see if it's down on compression, it should be minimum 930 kPa (9.5 kgf/cm2, 135 psi) at 250rpm.
killing_time
Members
Ok, then that would explain that the fouling
So it looks like oil is leaking into cylinder 4 and get caught up in the combustion cycle leading to the fouling of the plug. Now, it could be any of the following:
1. Valve Seals
2. Piston Rings
3. Cylinder Bore lining
4. Piston itself
Anyhow, you'll need to get a compression test done on Cylinder 4 to see if it's down on compression, it should be minimum 930 kPa (9.5 kgf/cm2, 135 psi) at 250rpm.
I will check compression. What if compression is ok?
If compression is ok, then the oil isn't getting in via the rings or valves. But it could be via the value seals. Get the compression test and go from there! Burning 1 litre / 500 miles is waaay too much and would indicate a leak or buring.
killing_time
Members
I will do that. Thank you very much.
I will do that. Thank you very much.
Ok, best of luck! Let us know how you get on.
killing_time
Members
I have done the comprssion test, and it's not good for the 4th cylinder.
It seems that the cylinder head is deformed...
It seems that the cylinder head is deformed...