02 limited 4.6 considerable amount of oil consumption

[jrobie79]

So to recap my recent problems with my 4.6:

Noticed an occasional 6th cylinder misfire code, very random, and not often.

Figured I'd get new plugs as part of my new ownership maintenance. Also noticed I was using up oil at a higher than what seemed normal rate - I check it all the time, just a habit.

Fast forward to this weekend, I popped off the engine cover and noticed liquid oil pools right around the valve cover/coils/boots/injector area. Like little pools of liquid oil - not just fuzzy sprayed oil on surfaces. I also noticed the 6th cylinder spark plug hole has been repaired, with some sort of extension, that put the plug electrode about 1" above where it should be - I a fixed that with a helicoil, and snugged down the plug and thought all was good in terms of the misfire...

Friday after this repair I left from Boston to Montreal - made it up there fine - checked oil, and coolant, all seemed fairly unchanged. Today when we went to leave, I immediately get two codes from my OBD bluetooth adapter - I checked because I felt the bogging - 5th and 6th cylinder misfire. Stopped and pulled off the coils, wiped the oil from them and went on my way. 5th cylinder code disappeared - 6th still there...going to replace all plugs and coils, so we'll see what that does to the misfire code. now onto the confusing part:

I noticed when I dropped my buddies off, a good puff of blue smoke after accelerating from a stop - and its running even worse (only code still 6th cylinder). I check the dipstick, it's down to about the last millimeter of the cross hatched area ( I topped it up to about 7/8 coverage on the hatched area before leaving this morning).

Would a leaking valve cover AND leaky intake manifold cause any of the leaked oil to drop into the intake and burn up upon accelerating from a stop? Didn't notice any blue smoke while driving, just acceleration from a stop. What else would be the oil consumption? I already bought a filter housing gasket, changing that tomorrow but I'm concerned with the liquid oil on top of the engine.

 

[LMHmedchem]

Allot of times when you are burning oil and getting blue smoke it means that the rings are going. This is usually bad news as you more or less have to overhaul the engine to redo your rings. It is more likely an issue with the valve cover gasket leaking. You can re-do all of your plugs and coils, but that won't fix a leaky gasket. You may have to replace the plugs anyway since they may all be fouled.

I don't know about the spark plug tube seals on this engine, but that is another possibility.
These links may help,
http://www.explorerforum.com/forums/showthread.php?t=402194
http://diy-auto-repair.wonderhowto....-leaking-spark-plug-tubes-your-engine-401384/

Generally, the tube seals are the easier and cheaper fix, so you could start there.

LMHmedchem

 

[jrobie79]

well, I'm thinking since the PO repaird the plug hole in cylinder 6, a bigger hole was tapped which was for that ****ty adapter, that wasn't meant for this engine....then I re-tapped the threads for the helicoil insert - which could have had less than ideal material to cut for proper tapping. This could possibly allow the leaking oil from the valve cover - it's significant - to drip into cylinder #6 combustion chamber and create the little bit of smoke, not to mention the misfire. I'm going to replace the valve cover gaskets and the intake manifold anyways - we'll see if the blue smoke is still there after that.

I'm going to see what prices are for a used head (I can install that myself, after machine work of course), and compare it to a time-sert BIG kit to determine if I need to revisit the spark plug hole/threads for cylinder 6

If it turns out to be the rings - I'm kind of at a loss there - I've swapped engines, heads, cams, gears, timing components in my 25 year old BMW...but never touched anything on the lower end aside from oil pan removal, so here's hoping

 

[jrobie79]

elp....bad news. Cylinder 6, compression...20psi. I hooked up the compressor to the head, and could feel slight air coming out the exhaust - must be an exhaust valve @ cylinder 6.

new question - what's the typical cost for a head job? Assuming it's only one bent valve, do I need to replace all valves on that side? What's needed - deck/cut, valve seats, should I replace all the rocker arms/springs?

 

[TechGuru]

elp....bad news. Cylinder 6, compression...20psi. I hooked up the compressor to the head, and could feel slight air coming out the exhaust - must be an exhaust valve @ cylinder 6.

new question - what's the typical cost for a head job? Assuming it's only one bent valve, do I need to replace all valves on that side? What's needed - deck/cut, valve seats, should I replace all the rocker arms/springs?

To be on the safe side I'd just get some freshly remanufactured heads.

RockAuto has them for $342.79 each.

 

[jrobie79]

To be on the safe side I'd just get some freshly remanufactured heads.

RockAuto has them for $342.79 each.

just the information I was looking for - should I change both? i've only ever changed heads on straight 6's and inline 4's, so there was only one. when i get the head off I'm gonna check the piston rings too, just in case, no point putting new heads on if the rings are junk.

 

[TechGuru]

just the information I was looking for - should I change both? i've only ever changed heads on straight 6's and inline 4's, so there was only one. when i get the head off I'm gonna check the piston rings too, just in case, no point putting new heads on if the rings are junk.

as I've said about other things anything that the vehicle has a "pair" of should be replaced as a pair whenever it is financially feasible.

If you have leaky rings I would run a thicker oil like Delo 15W40.

I personally hate V engines since they are twice the cost to rebuild.

My other two vehicles are inline 4 and inline 6. I wish there was a modern SUV with a inline 6 on the market. I would not be surprised if BMW has one but they're too expensive.

 

[jrobie79]

as I've said about other things anything that the vehicle has a "pair" of should be replaced as a pair whenever it is financially feasible.

If you have leaky rings I would run a thicker oil like Delo 15W40.

I personally hate V engines since they are twice the cost to rebuild.

My other two vehicles are inline 4 and inline 6. I wish there was a modern SUV with a inline 6 on the market. I would not be surprised if BMW has one but they're too expensive.

yeah their x5 6 cylinder is a straight 6... I've changed the head on my 1991 318is, ended up being a cracked block and changed the whole engine, never done anything like that on a V tho

I can get a 4.6 at the junkyard with 89k on it for $500, which is cheaper than two new heads, I'll have to do some thinking i guess

 

[D Hook]

I wonder if #6 cylinder got some metal shavings in there when they tried to repair the spark plug hole? Something that got stuck in the piston ring and scored the side of the cylinder wall maybe?

 

[jrobie79]

I wonder if #6 cylinder got some metal shavings in there when they tried to repair the spark plug hole? Something that got stuck in the piston ring and scored the side of the cylinder wall maybe?

I loaded up the tap with thick bearing grease to catch shavings, then proceeded to stick an open compressor hose down there for about 1 minute to blow anything out, and before I put the new plug on (right before I drove to Montreal) I attached my shop vac to a piece of hose that just fit in the plug hole and vacuumed anything out. I feel reasonably comfortable saying there weren't any shavings - if something was in there prior to my repair I can't say. The PO said something about rings and having to replace the plug every 4 months, but that would give me more than 20 psi of compression (assuming). I'm going to take the head off anything, because regardless I need to at the minimum replace the head and or new engine.

 

[jrobie79]

so I was reading another post on here regarding open valves - it appears it can be a couple of things - bent valve (removal of head), burnt valve (removal of head), bad lifter, or bad spring....I bought a borescope on amazon, I'm gonna take a look tonight, hopefully if everything looks ok, I'll just change the spring and rocker arm and give it a shot. Anything to avoid taking the head off at this point is worth a shot.

There isn't any metal on metal sound when running, so I'm wondering if the valve is stuck open, when the piston raises and hits it, maybe it just pushes it back closed as opposed to bending it? Can that happen?

In the event I need to change the engine (rings are ####ed, or there is cylinder wall damage) can I use any 4.6 from the 3rd generations? Are they different when they went to drive by wire? What about the 3v from the 4th gens? I obviously have all the accessories from my 02 that I can swap onto it, just want to expand my possibilities for pricing reasons

 

[Joe in NY]

.

 

[jrobie79]

I bought a new lifter/lash adjuster at O'Reilly last night and a rocker arm. I can't see anything wrong with the spring. I took the lifter out and put the new on in along with the new rocker. I took the front cam cap off and there is some scoring along the cam and the cap - is this junk?? (pictures below)

I also noticed there appears to be no oil restrictor as I've seen in some many other 4.6 engine posts/threads/youtube videos...any idea what's going on here:

 

[lincolnshibuya]

you could have done the leak down test so that you could exactly determine the source of the leak, usually when air is coming out of the dipstick (or in oil filler cap) then the piston us shot. air coming out from the intake and exhaust indicates a valve leak in intake and exhaust respectively.

when you did the heli coil fix, did you make the piston TDC? this will make it easy to pickup debris that fell down.

 

[jrobie79]

you could have done the leak down test so that you could exactly determine the source of the leak, usually when air is coming out of the dipstick (or in oil filler cap) then the piston us shot. air coming out from the intake and exhaust indicates a valve leak in intake and exhaust respectively.

when you did the heli coil fix, did you make the piston TDC? this will make it easy to pickup debris that fell down.

I did do a leakdown test (crude method of hooking compressor up - at 30 psi) and I felt slight air coming out of the exhaust, but not what I expect 30 psi would feel like. I could feel air coming out of cylidner #7 spark plug hole which is odd, so I put the plug in there and it didn't change the volume of air I was feeling out of the exhaust

 

[TechGuru]

Why only 30PSI? I'd run my full 150. Valves make leak a low pressure but not at high pressure since the pressure holds them tightly sealed better. Thinking about that if that occurs your valves are probably covered in carbon, if bent/warped I don't think more pressure would help.

 

[jrobie79]

Why only 30PSI? I'd run my full 150. Valves make leak a low pressure but not at high pressure since the pressure holds them tightly sealed better. Thinking about that if that occurs your valves are probably covered in carbon, if bent/warped I don't think more pressure would help.

well I upped it to 100 to see if i could tell any difference, I could hear? air coming from somewhere, but I figured it might just be the air circulating through the cylinder/head/etc, and again still no real noticeable increase in flow coming out the exhaust, and nothing coming out the intake nor oil dipstick