91 Explorer - just plain worn out?
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Mountain Pass
Joined: Oct 2004
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From: Southern California
91 Explorer - just plain worn out?
256K miles on the old beast. Didn't pass CA smog check. #2 plug was so clean I thought maybe an injector was clogged. Local shop says dirty injectors all around, low compression, on #2 cylinder. Hopefully clean injectors and a can of goo in the crankcase will get me through smog. Otherwise, I'll have to put her down at the end of the month. Any suggestions?
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Is your check engine light on? Check for codes even if it isn't on. If no codes, when was the last time you changed plugs, wires, air/fuel filters, etc.? Maybe the old gal just needs a good old-fashioned tune-up.
How did it fail the smog test? If I recall, the test measures hydrocarbons (HC), oxides of nitrogen (NOx), and carbon dioxide (CO2). If it failed the NOx test, the cause is almost always the EGR valve. HC failure could be the catalytic converter. If the CO2 reading is too low, I'm not sure what would cause that.
How did it fail the smog test? If I recall, the test measures hydrocarbons (HC), oxides of nitrogen (NOx), and carbon dioxide (CO2). If it failed the NOx test, the cause is almost always the EGR valve. HC failure could be the catalytic converter. If the CO2 reading is too low, I'm not sure what would cause that.
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Mountain Pass
Joined: Oct 2004
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From: Southern California
Failed on hydrocarbons - at idle max allowed is 120ppm/gross polluter 270ppm/measured 2927(!!!) ppm. Similar condition at 2400 RPM - max 180 ppm/gross polluter 330 ppm/measured 735 ppm. Carbon monoxide was a little high but within limits. Looks like a lot of unburnt fuel. Compression on all but #2 cylinder was 150 -160 psi. # 2 cylinder 60 psi.
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Originally Posted by krautwolf
Failed on hydrocarbons - at idle max allowed is 120ppm/gross polluter 270ppm/measured 2927(!!!) ppm. Similar condition at 2400 RPM - max 180 ppm/gross polluter 330 ppm/measured 735 ppm. Carbon monoxide was a little high but within limits. Looks like a lot of unburnt fuel. Compression on all but #2 cylinder was 150 -160 psi. # 2 cylinder 60 psi.
Sounds like either the compression ring on #2 is bad, or the valves aren't fully closing. Either way, yeah, the mixture isn't being compressed enough to detonate. You did mention that the spark plug on that cylinder looked too clean.
Might as well try using Seafoam or one of the "miracle" additives. Sure can't hurt at this point.
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Joined: Apr 2004
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From: North of Salt Lake City
I'm really curious what the Seafoam will do. Like was said above, pull some into the head and let sit for 30 mins. Start it up and watch the fog roll in. I've used Seafoam and had excellent results but it would be interesting to know what a dose of the good stuff will do for some seriously dirty valves. Let us know how it goes.
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Joined: Jan 2005
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From: Newport, DE
With that high mileage, you'll probably want to do seafoam a few times, and you'll want to let it sit for much longer. Say an hour or 90 mins. The longer it sits, the more varnish it will remove, and the more smoke you'll get.
I did it on my 93 Bronco, and let it sit for an hour and a half. So much smoke it looked like my house was on fire!
However, I don't think seafoam is going to reduce your HC rating enough to get through inspection.
When was the last time you changed your Catalytic Converter?
If the #2 cylinder has been bad long enough, it might have fouled your Cats to the point of uselessness.
You'll need to rejuvenate that #2 cylinder some how and probably change the cats too.
Don't quote me on this, but I've heard of old car guys using some sort of aeresol (I wish I remembered what it was) on piston rings by actually spraying it in the Spark Plug hole and let it soak into the piston rings for 20-30 mins. Now, I've never tried that, so I can't vouch for it or anything, but maybe someone has heard of what I'm talking about and can give better details.
I did it on my 93 Bronco, and let it sit for an hour and a half. So much smoke it looked like my house was on fire!
However, I don't think seafoam is going to reduce your HC rating enough to get through inspection.
When was the last time you changed your Catalytic Converter?
If the #2 cylinder has been bad long enough, it might have fouled your Cats to the point of uselessness.
You'll need to rejuvenate that #2 cylinder some how and probably change the cats too.
Don't quote me on this, but I've heard of old car guys using some sort of aeresol (I wish I remembered what it was) on piston rings by actually spraying it in the Spark Plug hole and let it soak into the piston rings for 20-30 mins. Now, I've never tried that, so I can't vouch for it or anything, but maybe someone has heard of what I'm talking about and can give better details.
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Mountain Pass
Joined: Oct 2004
Posts: 205
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From: Southern California
Well, I poured the magic additives to the oil, fuel, and cylinder head in question. Experienced a brief increase in compression with smoke in the exhaust, then performance reverted to the original condition. It appears as though the #2 cylinder rings are simply worn out. BTW, muffler, cat converter, water pump, power steering pump, and muffler were just replaced. Cost: $1200 parts & labor. Ouch.
Thanks for all your support. Went out with the wife and bought a Freestyle Saturday. The Explorer now lives outside like an old, incontinent pet. No decision on her disposition yet. Will advise/KW
Thanks for all your support. Went out with the wife and bought a Freestyle Saturday. The Explorer now lives outside like an old, incontinent pet. No decision on her disposition yet. Will advise/KW
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Originally Posted by krautwolf
Well, I poured the magic additives to the oil, fuel, and cylinder head in question. Experienced a brief increase in compression with smoke in the exhaust, then performance reverted to the original condition. It appears as though the #2 cylinder rings are simply worn out. BTW, muffler, cat converter, water pump, power steering pump, and muffler were just replaced. Cost: $1200 parts & labor. Ouch.
Thanks for all your support. Went out with the wife and bought a Freestyle Saturday. The Explorer now lives outside like an old, incontinent pet. No decision on her disposition yet. Will advise/KW
Thanks for all your support. Went out with the wife and bought a Freestyle Saturday. The Explorer now lives outside like an old, incontinent pet. No decision on her disposition yet. Will advise/KW
