uneven wear on NGK platinums after 45k

[89Ru]

95 OBW 181k 5-speed 2.2l

years ago I bought into the gleam of long service life on NGK platinums bkr6egp.

recently idle has been running rough (shakes the car) so figured it was time for new plugs.

well after 45k here's the platinum spark plug gaps in mm and cylinder numbers

 

front

DS----------------PS

#2 [1.1] ------- #1 [1.6]

#4 [1.8] ------- #3 [1.2]

 

weird how unbalanced the gaps were...on cylinders 1 and 4 the electrode was just about gone.

#4 ground electrode was ash fouled, others look fine

installed NGK BKR6E11 coppers today set to 1.05 mm

running a little rough at idle around 600 rpm warm

gets worse at 750 rpm

smoothes out at 1000 rpm

coilpack is probably original

air filter new, knock sensor replaced not too long ago, no codes

will try plug wires and fuel filter, pcv valve

I don't think its motor mounts because the vibration was happening before the new plugs and it would come and go

could a failing cat do this?

maybe a vacuum leak somewhere

Since this is a '95 it has HLA's and therefore no valve adjustment.

going back to 30k intervals on copper plugs

Edited December 3, 2012 by 89Ru
reading tach wrong

[Fairtax4me]

Wasted spark systems tend to wear the center electrode of one plug and the ground ground electrode of the opposite plug. Ground electrode is quite a bit larger than the center electrode on a platinum tip plug. Even though platinum plugs are supposed to last longer they don't work as well as plain copper plugs in wasted spark systems.

 

Ash fouling could be oil or coolant, or it could have something to do with fuel quality. Being on only one cylinder might indicate a dirty injector. Could mean a sticking valve as well.

 

Try new wires and some good injector cleaner first. If that doesn't help I'd check compression and maybe do a leak down test.

[1 Lucky Texan]

i learned something new - cool

[naru]

maybe a vacuum leak somewhere

 

I know a lot of 90s Fords(probably many others too) had 2 different spark plugs on the same engine.Difference was location of the platinum.

I just installed a set of Denso double platinum plugs (platinum on both electrodes) on an 99 exploder.

 

I am sure the engineers would not have specified platinum plugs if cheaper plain copper plugs were equally good or better.

[porcupine73]

On the 2.2L right I would just stick with v-power's instead of iridium since they're pretty easy to change. It's good you checked them at 45k, sometimes if you leave those things in for the full 100k they get siezed in the head.

[davebugs]

IMO Subaru's atleast 95-99 are best with the plain old NGK 2 dollar V groove plucs (they have green writing on the plug) rather than fancier plugs - even if MGK's.

 

And I've witnessed Bosch Platinums cause problems in many brands/models of cars.

 

Sometimes sticking with stock plugs, and in the case of Subaru 2.5 DOHC OEM wires just makes sense.

[johnceggleston]

Sometimes sticking with stock plugs, and in the case of Subaru 2.5 DOHC OEM wires just makes sense.

 

run the stock plug for your car. maybe a more expensive plug is better, but the stock plug is guaranteed to be good enough.

 

i had to order the stock plug for my 95 lego at advance. they had a different plug in stock, ''just as good'', but i went for stock. with no regrets. buying ''better'' plugs is such a scam at the parts counter. kind of like at the movie theater, ''for 50 cents you get twice as much soda.'' as if you are buying the $4 soda for the value.

 

i think, the only reason they don't use the same plug in the ej25d is due to the difficulty in changing them. the plug spec-ed for that engine lasts longer. but again, no reason to go fancier or more expensive.

[89Ru]

Thanks all! FairTax, that's a relief, was thinking bad things were happening down there and its just a product of the wasted spark and too many miles.

 

yep, green lettering on $1.54 plugs. plugs came out mostly like butter, only one screeched a little, maybe antiseize when I put them in helped.

 

Checked all plug wires while running using a timing light, saw some bizarre patterns. Sometimes regular flashes, sometimes nothing at all, sometimes regular spacing with random bursts of speed. All the cylinders seem to have different patterns. Went over to another EJ22 that runs smoother and saw similar types of patterns, although not as erratic. I'm thinking my timing light has a bad pickup or something.

 

Replaced plug wires with OEM. I imagined it made a difference at first (you know, how the car runs better after a wash) but it was wishful thinking. Still vibrating at idle, maybe a little less. To get a sanity check I checked vibration on a '96 OBS (one year different EJ22 SOHC engine) no vibration at idle or other weirdness like in the '95.

 

Here's some new info. Timing belt has been in for 53k. I forgot to mention this but at startup while cranking it sounds like it skips or misses once or twice, which I chalked up to maybe the starter going. Could it be a slipped t-belt, maybe on one cam? Its probably the original tensioner.

 

Could be something amiss on cylinder 4, was ash-fouled last time I changed plugs too but it just started running bad recently. It doesn't feel like its lost power but just the same its been 7 years since BG44K and 2 years since seafoam treatments in the gas.

 

Corrected the rpm's on the initial post.

[Fairtax4me]

Ash fouling could just be a small amount of oil or coolant getting into the cylinder. I would lean more towards oil if this has been a long term occurance. Sticky/worn rings, or a scratched cylinder wall. It hasn't progressed to total oil fouling so its only so bad. Compression/leakdown results would be interesting to see.

 

Timing is easy to check. Remove the two side covers, set crank at TDC, there is a small notch in the outer section, (hard to find sometimes but it's there) line the notch up with the 0 on the timing scale on the center cover. Big Arrows on the cam sprockets should be straight up.

Very easy to tell if one is off.

If you can't find the mark on the crank pulley you'll have to remove it and remove the center cover to see the notch on the crank sprocket.

 

Standard timing lights don't work on these wasted spark systems. They count too many pulses and get confused. There are lights that work but they cost a fortune. Ignition timing is not adjustable on these anyway so there's really no point in even bothering to check it. It really doesn't tell you anything.

[Caboobaroo]

I think Subaru recommends replacing the plugs every 30k because of the wasted spark system. I would use the NGK V-Power plugs and change every 30k.

[89Ru]

Compression/leakdown results would be interesting to see.

 

Compression check (done cold, I know should have done warm)

Removed injector and coilpack connectors, removed all plugs, checked each cylinder one at a time while cranking until the reading peaked on the gauge (about 7-8 cranks), while flooring the pedal.

 

results

1: 200 psi

2: 180

3: 205

4: 90

 

Help me decipher whether #4 has troubles (wouldn't be surprised) or whether a tooth or two off timing could be the cause (kind of doubtful at this point). Wish I had done a compression check the last time I did plugs 45k ago.

 

Timing is easy to check. Remove the two side covers, set crank at TDC, there is a small notch in the outer section, (hard to find sometimes but it's there) line the notch up with the 0 on the timing scale on the center cover. Big Arrows on the cam sprockets should be straight up.

 

Did that. Hard to see the tiny mark on the crank pulley. If I'm looking at the right mark its 14 degrees to the right when the big arrows on the cam 'spokes' are straight up. Lots of paint splashes on the crank pulley but these don't appear to highlight any marks. Also, lining up the other sets of marks on the cams (the painted lines on the outer rim of the cams) to the notches on the back cover shows that they line up together so it doesn't appear that the cams jumped relative to each other. Its easy enough to remove the crank pulley and center cover...

 

Standard timing lights don't work on these wasted spark systems. They count too many pulses and get confused.

 

The light wasn't the only thing confused that day So what are these old timing lights good for on distributorless ignitions?

[Fairtax4me]

Do a wet test on number 4 and see if the number comes up any. If it comes up the rings are worn. Hard to imagine the rings being that worn and not using a LOT of oil between changes.

 

Cam timing is ruled out because that would affect both cylinders on that bank. With only one cylinder affected the problem is limited to that cylinder.

 

A burned exhaust valve seems likely.

[1 Lucky Texan]

was fuel still being pumped in from the injectors? or id that injector stuck open w;ever?

 

could be cylinder wash-down from too much fuel. Of course, could be some other/worse things - just suggesting something kinda hopeful.

[89Ru]

Do a wet test on number 4 and see if the number comes up any. If it comes up the rings are worn. Hard to imagine the rings being that worn and not using a LOT of oil between changes

 

Repeated the dry test just for grins...just shy of 100

Squirted 10 cc's of oil into #4

compression jumped up to 165...by jove its...rings

 

It does use oil, maybe 2 quarts between changes, thought it might be the plastic oil separator plate but now that I think of it, if it sits for a while (few weeks) it smokes when it starts up. It did that when we bought it 80k miles ago. Tailpipe was black with soot but the mechanic I had check it out said it was 'running rich' and that was a good thing..maybe the next car we consider gets a compression check before any cash parts hands if things look odd. Maybe its always idled a little rough...it has used oil ever since we bought it.

 

You have done a fabulous job of diagnosing this machine unseen with only a partial story, my hats off

 

poor little ej22 , our 2nd subaru (wife's car at first but now she drives a fun little OBS)

[89Ru]

was fuel still being pumped in from the injectors? or id that injector stuck open w;ever?

 

could be cylinder wash-down from too much fuel. Of course, could be some other/worse things - just suggesting something kinda hopeful.

 

If the compression fitting comes out dry with injectors unplugged, I guess that means no fuel got into the cylinder...I'm being schooled on this so I appreciate all help and a little hope is what this car needs now, and a good wrench-turner.

[89Ru]

Did a leak down test at 15 psi.

Firing order 1-3-2-4

Crank position is 180 degrees (half turn) between cylinder TDC's.

Wasn't exactly sure where TDC was but was pretty close, had to hold the crank otherwise the pressure would rotate the shaft. Cylinders 1,2,3 held pressure but 4 didn't. #4 hissed constantly (where I don't exactly know but I didn't hear it at the tailpipe). Varying the crank position +/- 45 degrees around where I thought TDC was but never sealed up the #4 cylinder. 1/4 turn CW caused the hissing to turn into bubbling but nothing in the overflow tank. Never done this before but I think the results show that my #4 valve(s) are burnt from running with bad rings for uggh...years

 

Here's the platinum spark plugs, #4 on right after 45k miles. Being ignorant I would call it ash fouling but with the symptoms now it must be oil fouling, or maybe both.

 

 

 

Oil consumption is probably 1 quart every 750-1000 miles and I ran it down 1-2 quarts several times over the past few years. Not sure why just one cylinder would have bad rings. I did the oil pump reseal years ago and have done oil changes every 3-5k. Given its condition I'm happy I got 80k out of it, was hoping for 120k more but still, running on bad rings for this long I'd buy another one today.

 

What are some options? Its a third car but I don't have the skills to rebuild it. I'm leaning towards parting it out or selling it cheap to a rebuilder. How long would it run before the valves are so bad it won't start?

[Fairtax4me]

Rings in this case. . I kinda wonder if the rings are just stuck. Some MMO or Seafoam in the oil as a cleaner could free them up. Another member here had a similar problem a couple years back and Seafoam freed the rings. He got another couple years out of it before a spark plug shot out of the head.

For $7 it's worth a shot to see if it helps.

Pour in half a can drive 100 miles and change the oil, then repeat.

 

 

Ash deposits as I said before usually indicate a small amount of oil/ coolant, or some other form of contaminant in the combustion chamber.

Oil fouling would mean the plug is wet black with oil all over the tip.

Edited December 5, 2012 by Fairtax4me

[89Ru]

I kinda wonder if the rings are just stuck. Some MMO or Seafoam in the oil as a cleaner could free them up

 

Idled for 2 hours in the driveway with 1/2 a can of seafoam in the oil. New compression (done cold) numbers are:

 

before --> after seafoam

1: 200 --> 200

2: 180 --> 185

3: 205 --> 205

4: 90 --> 160

 

Starting is back to normal, without the periodic skipping cough. Idle smoothed out a LOT after 30 minutes at idle and after 2 hours seems normal. Hard to believe (that's my Eeyore coming out). Going to run it some more and then change oil.

[Fairtax4me]

Hell yeah that's awesome!

Change the oil and do it again?

[89Ru]

Change the oil and do it again?

 

Naah, I think I'll dump a can of red bull in there and see what happens. Going to change my name to Inspector Clusoe.

 

Just kidding, I think another round of seafoam is in order

[bulwnkl]

A suggestion:

 

Run an Auto-RX treatment rather than any more Seafoam. It safer (doesn't compromise the lubricating properties of the oil, and doesn't dislodge any 'chunks'), much more thorough, and I've never seen nor used anything better. I had similar or even better results with it in my '91 XT6 with low compression than what you're seeing with Seafoam. Only 'down' side is that it is slower/takes more miles than this kind of treatment.

 

Good luck!

[89Ru]

Well this is turning out to be a hijack of my own thread.

 

Run an Auto-RX treatment rather than any more Seafoam...I had similar or even better results with it in my '91 XT6 with low compression than what you're seeing with Seafoam

 

Thanks for the idea. Engine is currently being treated with second seafoam treatment in the crankcase. I'm driving it around this time keeping rpm's low, have about 60 miles so far. Results have been, well....inconclusive. Rough idle comes and goes which I presume means I'm losing compression again in #4.

 

Today I tried seafoam in the intake through the PCV valve. There sure is a lot of conflicting information on youtube how to do this. Don't use the brake booster hose, car runs like crap with this disconnected and flow appears to favor #4 cylinder (might be good for crud in #4?) but first time I would rather balance out the cleaning for all four. Maybe this vacuum plumbing has something to do with #4 having issues...cylinder runs at a different temperature and crud builds up? doubtful otherwise it would be more common...

 

whether right or wrong, here's my procedure:

measure 1/3 can of seafoam, nicely fits into a clean 5.5 oz. cat food can

with engine warm, running, disconnect pcv hose

attach old heater bypass hose to pcv with funnel

increase rpm to 1500 while SLOWLY pouring seafoam into funnel

(first time I dribbled a little into the funnel at idle, engine quit hence the increased rpm, hydrolocked? started right up though...)

smoke should appear from TP

shut engine off for 5 min

restart and run at 1500 or so until tailpipe blows clear

 

intake treatment did not improve idle, in fact, when running at 1500 unloaded something seems to slightly labor the engine by a couple hundred rpm every few seconds.

 

I'll look into the auto-rx. its good to have options. haven't tried MMO yet either.

[Fairtax4me]

Seafoam doesn't burn very well, so it impedes combustion of the fuel /air mixture. You pretty much have to hold the throttle at about 1500-2000 rpm to keep the engine running when feeding it into the intake or the engine will stall. And you will probably have to hold the throttle open after restarting for a little while as well. It will cause some rough and stumbling for several minutes after restarting. The trick is to take it for a short drive after you've got the initial plume of smoke out of it. That gets the air moving and pulls the rest of the unburned crud out of the intake.

 

Brake booster hose doesn't allow air into the intake unless there is a problem with the booster or hose. It's a source of vacuum, not airflow, for the booster.