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Old 20th November 2019, 09:39   #31
Rsnail
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I'm starting to think that the misfire is happening because of the bad lifter/s that I have now for almost half a year, maybe the lifter on cylinder 5 wore so badly that the valve is not properly closing anymore, hence the misfire, any thoughts? Meanwhile I'm still waiting for the spark plugs to arrive, those would be the last "cheap" fix that could cure it, already swapped everything from one cylinder to another and still the misfire stays on nr 5...
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Old 20th November 2019, 10:25   #32
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I'm starting to think that the misfire is happening because of the bad lifter/s that I have now for almost half a year, maybe the lifter on cylinder 5 wore so badly that the valve is not properly closing anymore, hence the misfire, any thoughts? Meanwhile I'm still waiting for the spark plugs to arrive, those would be the last "cheap" fix that could cure it, already swapped everything from one cylinder to another and still the misfire stays on nr 5...
Compression test will tell you.
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Old 20th November 2019, 10:32   #33
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But before opening the engine there is no possible way of knowing if it's actually bad lifters or bad piston rings or something else right?
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Old 20th November 2019, 10:38   #34
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But before opening the engine there is no possible way of knowing if it's actually bad lifters or bad piston rings or something else right?
Correct, but it will tell you that something is not right if the compression is low, or if the compression is good that the rings and valves are sealing.
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Old 20th November 2019, 12:35   #35
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Quite thought so. Although, as I said, I also have gasoline in my oil, it is obviously forced down in the oil pan by the piston rings, and regarding this, I know what I am saying is a far reach, but wouldn't it be logical that this is happening because the tappet on cyl 5 is either worn or blocked? Otherwise shouldn't the gasoline be thrown out the exhaust pipe? Now the only thing that comes out of the exhaust in comparison to before the misfiring is some white/greyish smoke.
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Old 21st November 2019, 21:51   #36
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Dissapointing news. Spark plugs arrived, changed the easy ones on the right side of the engine (front to say so) and drove the car for about 2 miles, both on idle and even in 5th gear while driving 30 miles per hour it was running PERFECT, like new, no misfire at all, not even the slightest. Then I thought ok everything's back to normal now, let's take the intake manifold off and change the 3 ones from the back side, did so, went for a ride again, and everything went back to being wrong again, misfiring on idle again, although just a little better while normally driving...

I can't imagine now really. How can it be that with only the 3 front easier plugs replaced with new ones, the engine runs perfectly smooth again and after changing the other 3 ones with new ones of course, it misfires like hell again? This is really frustrating now.
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Old 21st November 2019, 22:24   #37
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Did you do a compression test yet? Worn valve stem or valve stem seal will allow fuel to get up into the cam box and thus into the oil. The valve may not be seating properly, seat may be burned/damaged, stem may be carbonised or gummed up, causing it to stick. I think a compression check would be a quick and easy way to check symptoms.
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Old 22nd November 2019, 05:50   #38
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It was meant to get a compression test yesterday, but after replacing the front spark plugs and seeing that everything was perfectly fine again I called my mechanic and told him not to come anymore. I shouldn't have changed the rear spark plugs also and maybe it would've still ran perfect even now lol.

Anyways, what are the normal values for the KV6 on a dry and also on a wet compression test? And also what fuses do I have to remove to not get a spark and also no fuel into the heads?
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Old 22nd November 2019, 08:38   #39
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... let's take the intake manifold off and change the 3 ones from the back side ...
When you did this, was the small earth cable attached properly? As you stand at the radiator, it's on the far right hand side.

Also, there are two screws holding the back of the manifold chamber (the black plastic moulding) which are very difficult to see and reach. If these are missing it is possible to refit the chamber without it being properly sealed.

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Old 22nd November 2019, 12:47   #40
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If you are talking about the small earth cable on the front bank (closest to radiator), that one was always attached to the coil of cylinder nr 1, or cylinder 3 as far as I remeber, but for the rear bank I've had no earth cable there

Those screws at the rear for the manifold have been missing since I've installed the new manifold about 1 year ago, although I've never had problems regarding those missing screws...
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