Tick and oil consumption in cylinder 5

[mistermetoo]

N62 engine ticking issue, cylinder 5 misfire: consuming 1 qt of oil and one spark plug at cylinder 5 every 100 miles.

I've had to swap out a spark plug in cylinder 5 every 100 miles, otherwise getting a blinking to solid SES light. Anyone had this before? driving me crazy

I've asked in several threads if anyone's had the same... no hits yet.

updated with pictures under VC of bank 2

http://imgur.com/a/bqupZ

that is the link to the whole album of the shots of bank 2 with the valve cover off, (cylinder 5 is the problem)
- 15 pictures (my apologies for the shots that are redundant, i've posted directly the shots that i think may be most pertinent. i can't figure out if something seems off here aside from the oil deposits near cylinder 5

[David.X5]

What does the plug look like? Oil fouled?

N62 engines are well known for leaky valve stem seals. Could also be a damaged valve or worn/broken ring. Have you compared your symptoms to the threads on N62 Valve stem seals? If it's that, the good news is there are special tools to allow replacement without removing the heads.

[mistermetoo]

Originally Posted by David.X5

What does the plug look like? Oil fouled?

N62 engines are well known for leaky valve stem seals. Could also be a damaged valve or worn/broken ring. Have you compared your symptoms to the threads on N62 Valve stem seals? If it's that, the good news is there are special tools to allow replacement without removing the heads.

thank you for the response.

the plug looks oil fouled- prongs and the metal tip that the prongs meet at are all covered in black. i've gone through 7 spark plugs in cylinder 5 alone. on the dot, every 100 miles or less if i keep the car around 2.5k rpms. incredibly loud ticking at idle. it's unusual... i've been swapping plugs but without the swapped plug (letting the car remain in SES mode), the sound is muted if not there at all, as if the piston is floating in CEL mode?

updated initial post with pictures

[David.X5]

If that cylinder is consuming oil like that, the valves are likely to be caked with carbon and making a racket. Don't know if it can be saved, but valve seal replacement followed by chemical cleaner to remove the carbon deposits might be your best hope unless you are willing to consider the expense of full head reconditioning (but I would do more testing before that).

[mistermetoo]

Originally Posted by David.X5

If that cylinder is consuming oil like that, the valves are likely to be caked with carbon and making a racket. Don't know if it can be saved, but valve seal replacement followed by chemical cleaner to remove the carbon deposits might be your best hope unless you are willing to consider the expense of full head reconditioning (but I would do more testing before that).

could you please coddle me and sing me a lullaby about successful seafoam cleaning? i've been losing a lot of sleep over this
.
could it possibly be a fuel injector? i've read that they can clack and foul plugs. although that wouldn't explain the quart of oil it's taking down every hundred miles or so.

i drove 500 miles back and forth to new york in this condition, shamefully swapping spark plugs at rest stops complete with pitying onlookers.

[David.X5]

Well, cleaners are likely to help in the short term with the noise and carbon build up. I prefer redline. I've also had good luck with Rislone yellow. Don't know what is best for real heavy carbon. You can use one after the other... But, that won't stop your oil leak (I'm assuming it's a leaky valve steam seal) or keep the plug from fouling again.

[mistermetoo]

pulled this off NGK's website... works into my bad fuel injector theory:

Fouling range

As a by product of combustion, carbon will become deposited on components within the combustion chamber including the spark plug. Excessive carbon deposits on the plug can cause a misfire due to deterioration of spark quality. When the spark plug reaches a certain temperature it will start to burn off the carbon and enter a self cleaning region.

Fouling will occur if plugs are operating at lower than the self-cleaning temperature of

400 degrees Celsius – 450 degrees Celsius (750 degrees Fahrenheit – 850 degrees Fahrenheit)
or
Air-fuel mixture richer than 8:1 to 10:1

This can be seen as:

Wet Fuel Fouled – Wet Black Deposit

The firing-end of the spark plug becomes saturated with fuel and its insulation ability deteriorates and misfiring occurs.

Recommendation
Check for rich air/fuel mixture. Check the entire ignition system. If condition recurs, engine overhaul may be necessary.

Carbon Fouled

Black Carbon Fouling
Carbon accumulates in large quantity and, while the firing-end of the plug is dry, its insulation is abnormally decreased. This, too, is regarded as a prime cause of misfiring.

Recommendation
Check for rich air/fuel mixture. Check the entire ignition system and cooling system (excessive cooling).

Other fouling – Oil Fouled

When the firing end of a spark plug is fouled by oil, an electrical leakage path is formed and the insulation deteriorates, consequently the available voltage from the ignition system is lowered and a spark can not jump at the spark gap.

Causes of carbon fouling

Fuel mixture too rich
Excessive use of choke
Blocked air filter
Incorrect spark plug gap setting
Over-retarded ignition timing
Compression loss due to imperfect cylinder-piston seal or valve seating
Prolonged low speed driving or idling
Too cold a spark plug fitted
Causes of oil fouling

Lubricating oil entering into combustion chamber
Fouling range | NGK Spark Plugs UK

[upallnight]

I would have a leakdown test perform on cylinder 5 and the rest of the cylinders to determine the health of cylinder 5 compared with all the other cylinders.

Oil could be coming from a oil valve seal on the stem, or worn valve stem, or maybe a broken oil seal ring. A leak down test will narrow down the source of the oil problem.

[David.X5]

Injector cleaner won't hurt, but I suspect it is something more - leak down test and/or compression test is a good idea - pretty quick way to get some data about the health of the rings and valve seals before you start throwing parts at it.

If you can wait, I have sent injectors in for serious cleaning and spray measurements to Mr. Injector - very happy with his work and not very costly. Didn't use his free o-rings, though - I prefer the BMW ones. Some local performance shops can do this, too. But I couldn't find one within driving distance of me.

Mr Injector - Home
Bill Johnson / Mr Injector
6280 N Government Way Unit 4
Dalton Gardens, Idaho 83815

[mistermetoo]

think i found the issue. if you look at the initial pics i posted, the valve spring for cylinder 5 is off.