Oil on spark plug tips - only on 2 plugs -Oh No!!!

[Marde]

Hi guys!

This is my friends 2005 V6 4Runner with about 190K miles.

Looks like bad news coming. Guess I will be doing a compression test and leak-down test. Uhg. Never done these tests. Going to borrow the tester from Autozone. Any advise much appreciated.

When I do the wet test, do I use the same oil as inside engine, -mobile one full synth? How much oil do I place inside the cylinder? About a teaspoon or tablespoon?

Also, disable fuel system by pulling fuel pump fuse right? -and crank-it until no-start right?

Thanks for any help or suggestions. Cheers!

Timeline
Feb 2015 replaced leaking valve cover gaskets on both sides. Right side/bank-1 had previously leaked quite a bit of oil, but had no fresh oil leaking; left-side bank-2 had tiny or almost no leak. Also replaced all spark plugs with NGK LFR6C.

Unsure if misfires present before VC gasket replacement.

2 weeks later CEL and misfire codes P0300 and P0306.
2 weeks later pulled out plugs on #6 and #2;
#6 looks dark/burnt on electrode ceramic tip. #2 looked good/normal. Suspect defect with plug, coil or wiring on #6.
Moved #6 plug and coil into #2 position AND #2 plug and coil goes into #6 position.

Two weeks later CEL comes on; checked codes and had P0300 Random misfire. Cleared codes.
One week later CEL is back on, checked codes and had P0300 Random misfire.
Two weeks later CEL is still on, checked codes and had P0300 Random misfire. Car would not set a code for misfire on #2 or on #6.

May 16 2015:
Pulled out #6, #4, #2 spark plugs (bank-2);
#6 plug looks dark-ish but OK
#2 plug looks dark-ish but is a little wet with oil on the electrode ceramic and on electrode tip.
#4 plug looks same as #2 but might have even more oil (in same spot) as #2.
No oil on spark plug threads or inside of spark plug wells. Oil only on plug tips.

Then pulled out #3 and #5 spark plugs (bank-1). These two plugs look perfect.

 

[Marde]

Just got back from Autozone, got the compression test set in my hand now.

Checked owners manual for Fuel Pump fuse; is number 46. Open fuse box and #46 is not installed. Must be some kind of error in documentation verses actual car configuration. Ideas?

Found fuses #11 and #25 both are EFI, so I am going to pull those out in order to disable the fuel system.

Any thoughts guys, gals...? Thanks!

 

[fdbyrne]

I've never done a compression test on a 4th gen, but you are thinking correctly. You do need to pull the fuses for the fuel pump and fuel injection system.

Are you going to replace the head gasket yourself if you find out that it's bad? If not, don't waste any more of your time. Go ahead and find somebody to do it. I think you have sufficient evidence already.

 

[Marde]

I've never done a compression test on a 4th gen, but you are thinking correctly. You do need to pull the fuses for the fuel pump and fuel injection system.

Are you going to replace the head gasket yourself if you find out that it's bad? If not, don't waste any more of your time. Go ahead and find somebody to do it. I think you have sufficient evidence already.

Thanks for your reply. Just found the fuse problem; I was looking for a fuse, but no fuse is pulled out for this test; Fuel Pump RELAY is pulled out, not a fuse. Done similar on a Ford and pulled out a fuse not a relay.

Not enough evidence yet, but very close. Must at least perform this compression test and leak down test to get an idea how bad things might be. Least I could do.... because -YES- sadly I have no real experience doing engine rebuild stuff so going to have to hire someone else do it or... we shall see...

 

[Marde]

Found fuses #11 and #25 both are EFI, so I am going to pull those out in order to disable the fuel system.

Did this; pulled both of these fuses, and results are NO CRANK and NO START. Nice try, but not good for me. Later found fuel Relay, pulled this out, and bingo! Cranks! Engine ran for a few seconds then died. This is what I wanted.

 

[Marde]

Just finished compression test. Performed while all 6 plugs were removed.

All six ranged within 150 to 154 psi. I see no problems; but do not know what other people get on this engine.

Might not conduct Leak-down test today because I am uncertain on exact details of how to perform the test verses the gauge-set I am using. Gotta go study up on this... Gotta do it right or not at all.

NEWS FLASH: When I pulled the plugs, none of em' had oil on the tip. Car had only run 5 or 10 minutes total at idle since (last night) when I had cleaned them. Will likely (hope not) get oil-wet again when car gets driven each day next week... but seeing the plugs dry is indication that the "internal oil leak into #2 and #4" is not severe or consistent. Fingers crossed.