94 Civic CX Hatch
d16z6 swap

engine has about 150k miles on it (supposedly)

i rebuilt the head...sorta, new valve stem seals reground seats and valves (did not replace)

all new seals bottom to top, headgasket, water pump and timing belt etc(all non OEM)

anyways....after about 2 days and 10 miles of driving the ignitor went out on the distributor. so i changed my spare in. while troubleshooting the no spark issue i noticed the spark plugs.

in order from left to right cyl. 4 3 2 1

numbers 1 and 4 look great.

number 2 is oily...sucks

number 3 is....not sure it looks normal...for older plugs.

the engine burns alot of oil. either rings are shot or the new aftermarket valve stem seals are shot.

but the real question is, what is the explanation for the wear on number 3?

they only have about 50 miles on them at this point.

 

Isn't #3 also normal?

NGK Spark Plugs USA

 

Well lets say number 3 is normal. What about 1 and 4.

I agree that the wear on 3 appears normal. But 1 and 4 are clean. I guess they could be gathering coolant and cleaning them off.

Think i may have to get an oem head gasket and valve seals and try again.

 

Not sure. Maybe also normal or slightly lean in those cylinders?

Are you burning coolant?

 

#2 being oily could be a stuck open pcv valve. If my memory serves me correctly, the pcv system runs to intake runner #2.

#4 looks a little whitish in the picture. If it's actually tan then I'd say all of them look normal except the oil fouling of #2.

50 miles isn't very long to see the kind of buildup on new plugs to give a solid idea of whats going on.

I'd say a run of 250 miles or more is needed to get a decent "plug" reading from brand new plugs unless something is majorly wrong such as plug #2 with the oil soaked condition already.

The whitish could be just a nice WOT run just before pulling the plugs. The plugs run through a wide range of conditions with low rpm cool running to high rpm hot conditions. It's the wide range of operating conditions that makes it take some time (200+ miles) to see the full situation of the motor from plug readings.

Hope that is clearer than mud and is helpful.


Side note: As for the idea of burning coolant, it would be a little strange to be burning coolant on the outsides but not the middle of the head. Usually head gaskets pop in adjacent cylinders (side by side). Not saying it's impossible to be on the opposite ends simultaneously, just not very common as far as I know.

 

i put an ebay gasket kit by eristic on the motor...poor choice maybe.

anyways. i got the engine for $350 with 150k on it.

i decided to do all of the gaskets when i got it, then ended up working on the head. the intake runners, mostly 2 and 3, were caked with sticky oily black crap.

there was some slight vertical scoring on the cylinder walls, but the tops of the pistons looked good

the valves were not horribly caked with anything, just pitted from carbon buildup.

the valve stem seals that came with the kit did not CLICK into place like what i am used to which concerned me

it has slowly...slowly gotten better with some driving. i put an entirely new exhaust. flat black header with test pipe and a yonaka catback.

i figured some of the paint they used on the inside of the header and cat was alot of my smoke.

At this point if i go and start it up cold, it doesnt smoke. just moisture burning out of exhaust. after it gets warm and i rev it, i get blue smoke. at normal cruising it doesnt smoke that much. after decel, idle, or other high vacuum situations it smokes worse.

I did not change the PCV valve, but do not see any oil in the PCV tube either. i may change the valve and see if it improves. Yes it returns to the intake manifold in between 1 and 2 runners.

i just thought it odd to have 3 different looking spark plugs so soon. and wouldnt be surprised at all to find a valve stem seal on number 2 up around the retainer.

i do appreciate the responses. and will put some more miles on them and see how they look.

and i have no issues giving it the full range of driving...i live in the mountains in the curveys

 

They don't look that different except #2 with the oil. #2 usually is a touch darker anyway due to the PCV system.

#4 is farthest away from the water pump so tends to be the hottest cylinder so will be the lightest in color usually.

Your valve seals definitely could be the issue. You said you didn't get the click you are familiar with so they definitely could be miss seated.

If your coolant levels are fairly stable and none of the piston tops are totally void of carbon, I'd say your head gasket is working fine.

 

never put any thought to that note about #4.


coolant levels are stable. top hose is blown up like a baloon and needs changing. but stable

ill get a pcv valve and see if that helps.

i looked with a light in the cylinders none of them are steam cleaned.

im preparing to move, hopefully buying a house, i just threw this motor in real quick to get it moving...which it is. i hated putting money and time into it and seeing smoke, but it is what it is.

i have a second z6 i planned on rebuilding once i get settled in but definitely need this one to last a little while. it does however run great and gets up good for a z6. 100x better than smokey the d15b8

 

yeah, I'm a bit concerned about the oil of #2, other than that, it looks like the motor could run quite awhile.

The smoke is very likely from that #2, that is a pretty significant amount of oil for only 50 miles on the plugs.

It very well could be those particlar valve seals didn't seat, while the other 3 cylinders did.

The vertical abrasion on the cylinders could be contributing a little too.

You can always run MMO with your oil for a few rounds (1500 kilometers or more) to reduce the chances of sticky oil control rings.

Being you said the smoke is typically high vacuum situations, that points back at the valve seals.

If you bought another full set of valve seals, you have 4 tries at fixing up that #2 situation as the other 3 look decent. #3 might be leaking a little too but not as much as #2.

When you had the head off, did you check the valve play with a run out gauge by chance? If the play is bad enough, no seal is going to hold for long and you will just have to contend with high oil consumption and a little bit of smoking, fouling the plug regularly along with eventually fouling up the catalytic converter and possibly the O2 sensor. If it's sucking so much oil it's stuttering with a brand new plug, then you would be concerned.

I've been driving with bad valve seals for over a year now. So far the only thing that has taken a hit besides my pocket book for oil, is my cat isn't cleaning up the exhaust as well anymore. A citric acid bath would be good but I am putting that off until I get new seals in.

New PCV valve never hurts and is only a few bucks. Slap a new plug into #2, and pull it in 100 miles or so and see if it's still oil coated after the new PCV valve. Then go from there.

 

A cylinder compression test may distinguish bad piston rings or head gasket from bad valve seals.

 

I have a compression tester at my parents in storage.i plan to check Thanksgiving.

The oil on two is concerning.

I did not specifically check the play in the valves but i did do the wiggle test.while not scientifically accurate they were all relatively the same.

 

i have a picture of the head in my car, this is after i refinished the valves but before i put new plugs in. on my phone i can zoom it in.

looking at the old spark plugs, there is no oil fouling on any of them. they look perfect. gives me hope that its just the valve stem seals

i dont know how well you can see in the picture, but here it is

 

performed compression test on motor.

warm engine, 5 cranks each, dizzy and injectors disabled WOT

all 4 cylinders were EXACT. 120psi on first crank then climbed to 190 and rested. there was no visible difference in level they climbed but it was equal and quick.

obviously i have great compression.

i have lost 1 quart of oil...probably 300 miles.

i have a heck of an oil leak at the vtec solenoid but believe this oil burning must be stem seal related with those numbers.

 

You can probably fix the VTEC solenoid leak with some HondaBond.

 

i will probably just order the seal with my stem seals...from honda this time.

although. all of the other seals from the cheap kit are working perfectly so i cant complain...other than the difficulty in doing the valve seals. i compressed the valve springs by hand with a pair of long needle nose pliers....makes your hands hurt

also need to make or buy an air adapter to hold the valves up while i change them out