So, I had to come back to my thread after 3 months.

After repairs (replaced all O2 Sensors, spark plugs with Bosch Platinum+4s, wires - Kingsborne 8mm and air filter) the car was driving good, idle and acceleration were perfect, but still having SES light on and was showing again bad O2 Sensors and P0327 (bank 1 knock sensor).

Recently, as I was out of my city, I couldnt start enginge for 3 weeks and after coming it started to have some idling problems and also losing power.

Yesterday while driving it threw up codes and when i checked, it showed 17 codes:

P0300
P0301
P0303
P0305
P0307
these misfire codes were repeating, plus
P0327,
P0453,
P1319,
P0172,
P0155,
P0154,
P0135.
P1300

Today i tried to reset SES light and it came on with the same codes and I couldnt drive the car, i was pushing acceleration pedal, but the idle was not increasing. Then i heard some noise from the underhood, like knocking from the driverside as i presume. Can anyone help, what might be the reason, or where should i look for faults? I am taking car to mechanic on saturday, but I really want to know more and possible faults and causes before going there. I dont know if its connected, but car is leaking coolant, somewhere under the MAF, but I couldnt find any broken places. Can it be also connected with these power loss and bad idling? MAF was replaced in March. Please advise something if you have heard about such problem.

 

loss of coolent, misfiring, bad idle, could be a head gasket. has it ever been preasure tested to try and find the cooling leak? the cooling leak could also be the throttle body heater it is over next to the maf.

 

IMHO the coolant leak may be far more inexpensive than HG, but a coolant test is good idea. See Throttle Body Heater Plate Kit | Land Rover And Range Rover Fuel System Parts

This gasket leaks, and shows up under the MAF. In an emergency, you can bypass the hoses in/out. It warms the throttle butterfly valve to be sure it does not ice up and stick wide open when you zoom up the mountain and expect to coast down the other side. It is a serious safety issue in cold weather.

The throttle plate heater should not cause all these other codes, unless it is leaking coolant into the intake! As stated, you could bypass the in/out hose, reset codes, see if codes stay clear. Seems like you have everything on one side, and O2 sensors wiring or sensor is having problems. Now water in engine will do that.

P0300 multiple misfire - catalyst damage quite possible
P0301 misfire 1
P0303 misfire 3
P0305 misfire 5
P0307 misfire 7 Perhaps HG leak on one side of engine
or water from somewhere

these misfire codes were repeating, plus
P0327,
P0453, Fuel tank pressure signal low
P1319, low fuel level check
P0172, bank 1 rich
P0155, O2 sensor continuity circuit - front
P0154, C2S circuit continuity
P0135. O2 sensor continuity circuit - front

P1300 multiple misfire - catalyst damage.

 

Cooling system pressure test. A test for exhaust gases in your coolant. Like Buzz and Drowssap have said, its probably your throttle heater leaking. As far as your misfires, its your ignition coils. Yea, a headgasket leak would throw the same codes, but you be able to smell the coolant burning its an entire bank was burning coolant. If your igntion coil isnt firing correctly, then you would have insufficient spark, causing the excess fuel to be dumped into your cat (hence the flashing cel), complete lack of power, stubbling and ever symptom you have described.

 

Thank you guys for help.

I have checked Throttle body heater and its not getting wet underneath and looks quite fresh. I bought this car used and as I know from the repair history file, head gaskets and MAF sensor were replaced recently.


Are there any ways to check if ignition coil is firing correctly and if coolant is leaking into intake without visiting mechanic?

 

That answer is completely dependent on you. How technical are you? To test the coil, its in rave and the exhaust gases in coolant kit you can get at your neighborhood friendly parts store. Will post page #is when I get home. Don't have rave on my phone

 

I am brand new to this forum, and noticed all the trouble that you are having. I am by no means an expert, but when I replaced the original paper filter with a K&N hi flow reusable filter on my 2003 LR D2 (4.6L) I had terrible problems. All were solved by replacing the air filter with the OEM paper filter. I experienced all the the poor acceleration problems and misfires that you are describing. Let me know if it helps.

 

Thanks for suggestion. The problem is that I dont even have K&N filter. I am using normal Hengst paper air filter and I have changed it recently maybe 2-3 months ago.

I am mostly thinking that either head gasket is blown and coolant is running inside the engine or ignition coils are not working well. Yesterday I took the car to simple mechanic and he could not understand anything, was looking with surprised face. One thing he suggested was to pour some liquid in the coolant to stop leaking. Tomorrow I might take to normal mechanic and hope he might give right diagnose.

By the way, is it possible to have such misfires, flashing SES light and O2 Sensor codes if engine block is leaking coolant?

 

You made a wise choice not to pour in "stopz leekz" compound to engine. A head gasket leak could put coolant into multiple cyclinders, but so can one that is easier to repair, it is called the valley pan gasket. Coolant will cause misfires, etc. And O2 codes will pop up for many things besides O2.

See attached diagram of engine gaskets. In the drawing, #25 is the valley pan gasket, the intake manifold system sits on top of it. If head gaskets were done, this gasket was replaced AFTER the heads were installed. A common problem is sealing them (corners), and another problem is loose bolts on them. So your problem could be as simple as some loose intake manifold bolts that hold down the valley pan gasket.

Also attached is a diagram of the intake manifold system. This would not have to come off to just try tightening the bolts. They are #12 in that drawing, and the gasket is # 16.

Also attached is RAVE page on tightening the bolts.

Hope this helps you and your mechanic. You can download RAVE and make a copy on a USB drive to give mechanic.

 

So, i will update some information.

I brought yesterday my car to the mechanic. He replaced MAF sensor to check if it was the fault and as i was presuming my MAF sensor is working perfectly so, its not a reason. I left the car there and the guy will take engine head to check condition of gaskets. Meanwhile, as the engine will be taken apart, I will get new head gasket, belt tensioner and ignition coils if i will need it. As for the coolant leaking, there is some leak going from water pump and also as the mechanic said, head gasket is blown and the coolant is leaking outside the engine and not mixing with oil. Also there was some signs of oil leaking underneath the engine and he said to buy some seal, but I dont know how to look online for this seal as I am not from English speaking country and the mechanic didnt know English to explain. So, he said to replace front seal, not the back one and there wont be any sign of oil underneath the engine. Actually, since the oil was replaced, I have not added anything and I am checking once in a week the level and it stays normal all the time.

Can you suggest for which seal should I look for, the one which is underneath the engine in the front side and where there should be sign of an oil.