Intake Plenum Gaskets Codes P0171 & P0174
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Intake Plenum Gaskets Codes P0171 & P0174
Hello, Being unemployed since Feb. 09, I have tried to do most of the maintenance on our vehicles and home. The dreaded "check engine" light came on in my 4.0 L Ranger, so I checked it! It was still there.
Anyway I found this site while trying to come up with a solution after the local Advance and AutoZone came up with P0171 and P0174 codes. Checking all the vacuum lines and air cleaner hose found they were in good shape.
My brother in law tried his code reader as it is a little more sophisticated and came up with the same codes. We discussed it and I told him the sites I had looked at seemed to point to a common problem, the intake plenum gaskets. The engine runs well and did not indicate an air leak at a point beyond the MAF sensor. I had him reset the codes and did not start or move the vehicle. We both agreed the MAF sensor should be changed.
Did that, changed the PCV valve and fuel filter, started and drove as the manual says to retrain the trim.The light came back on! Tomorrow will do the plenum gaskets.
I found this pictorial on another site, which is good. Glad to be here.
How to replace upper intake manifold gaskets - Ford Explorer Ranger Enthusiasts "Serious Explorations"®
Anyway I found this site while trying to come up with a solution after the local Advance and AutoZone came up with P0171 and P0174 codes. Checking all the vacuum lines and air cleaner hose found they were in good shape.
My brother in law tried his code reader as it is a little more sophisticated and came up with the same codes. We discussed it and I told him the sites I had looked at seemed to point to a common problem, the intake plenum gaskets. The engine runs well and did not indicate an air leak at a point beyond the MAF sensor. I had him reset the codes and did not start or move the vehicle. We both agreed the MAF sensor should be changed.
Did that, changed the PCV valve and fuel filter, started and drove as the manual says to retrain the trim.The light came back on! Tomorrow will do the plenum gaskets.
I found this pictorial on another site, which is good. Glad to be here.
How to replace upper intake manifold gaskets - Ford Explorer Ranger Enthusiasts "Serious Explorations"®
Cross-Country
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I found the hole that was causing my trouble lean codes, and posted the pictures in my 'banging my head against the wall' thread.
I know you said you checked the hoses, but I thought I did too. Couldn't hurt to check the pics, eh?
I know you said you checked the hoses, but I thought I did too. Couldn't hurt to check the pics, eh?
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Appreciate the reply and "been there, done that". The engine in the truck is a pushrod, slight difference from the SOHC.
I did review your post even before registering on the site, which is a great resource. After the PCV valve was replaced, started the ol gal just to listen. Above the noise fro the belts and cooling fan pretty sure there's a slight hiss from below the intake.
Didn't do the Propane or smoke test, but did try some starting fluid. Only trouble is the driver's side of the plenum has numerous items in the way. I did put pressure on that side with my hand and the hiss was not so noteable.
The truck really runs well, never was known for great gas mileage, so every little bit helps. Plus the myth or fact that the ol brain dumping more gas because of a lean condition, can shorten the life of the oxygen sensors and catalytic converter.
Again, nice post with pictures from you.
I did review your post even before registering on the site, which is a great resource. After the PCV valve was replaced, started the ol gal just to listen. Above the noise fro the belts and cooling fan pretty sure there's a slight hiss from below the intake.
Didn't do the Propane or smoke test, but did try some starting fluid. Only trouble is the driver's side of the plenum has numerous items in the way. I did put pressure on that side with my hand and the hiss was not so noteable.
The truck really runs well, never was known for great gas mileage, so every little bit helps. Plus the myth or fact that the ol brain dumping more gas because of a lean condition, can shorten the life of the oxygen sensors and catalytic converter.
Again, nice post with pictures from you.
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From: SW Va
Welcome to FTE.
Since you like to turn wrenches on your Ranger, be sure to visit the "Tech Info" thread atop this forums thread listing page for good info.
Since you suspect your intake manafold gaskets, have you tried retorquing the fastners????
If no joy, I'd do some more intake manafold & vacuum source leak testing, to verify the leak source, before tearing into the intake manafold gasket replacement job.
If you do find the intake gaskets are the culprit, be sure to look up the Tech Info thread post with pictures by Rockledge, on how he replaced those gaskets on his 4.0L pushrod engine.
Might be helpful if we had a little historical info, like the year, model, mileage & where you are on all due past & present scheduled maintenance.
BTW, why did the both of you decide the MAF sensor should be replaced????
Since you like to turn wrenches on your Ranger, be sure to visit the "Tech Info" thread atop this forums thread listing page for good info.
Since you suspect your intake manafold gaskets, have you tried retorquing the fastners????
If no joy, I'd do some more intake manafold & vacuum source leak testing, to verify the leak source, before tearing into the intake manafold gasket replacement job.
If you do find the intake gaskets are the culprit, be sure to look up the Tech Info thread post with pictures by Rockledge, on how he replaced those gaskets on his 4.0L pushrod engine.
Might be helpful if we had a little historical info, like the year, model, mileage & where you are on all due past & present scheduled maintenance.
BTW, why did the both of you decide the MAF sensor should be replaced????
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Thanks pawpaw.
2000 Ranger XLT ,4.0L, 4X4, 4 DR, Auto-5 SPD, OFF ROAD & TOWING PKG, 16" WHL/TIRES - Mostly City & Highway - 54K MI - NORM Maintenance SCH Followed and Current - Until last year by the local Ford dealer - NO MUDDING OR TOWING
I like the way you think and had decided to hold off until Saturday for the gaskets. I will try retorquing now. As far as the MAF, vacuum is good, all lines check out, and we thought maybe it might be intermittently failing as it did check ok. The hiss I hear is slight, but maybe just enough to throw the codes. No real idle or driveability problems that I notice. Now if I can just find the torque wrench, one of the reasons I put it off.
Thanks
2000 Ranger XLT ,4.0L, 4X4, 4 DR, Auto-5 SPD, OFF ROAD & TOWING PKG, 16" WHL/TIRES - Mostly City & Highway - 54K MI - NORM Maintenance SCH Followed and Current - Until last year by the local Ford dealer - NO MUDDING OR TOWING
I like the way you think and had decided to hold off until Saturday for the gaskets. I will try retorquing now. As far as the MAF, vacuum is good, all lines check out, and we thought maybe it might be intermittently failing as it did check ok. The hiss I hear is slight, but maybe just enough to throw the codes. No real idle or driveability problems that I notice. Now if I can just find the torque wrench, one of the reasons I put it off.
Thanks
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From: Connecticut
...Tomorrow will do the plenum gaskets. I found this pictorial on another site, which is good. Glad to be here.
How to replace upper intake manifold gaskets - Ford Explorer Ranger Enthusiasts "Serious Explorations"®
How to replace upper intake manifold gaskets - Ford Explorer Ranger Enthusiasts "Serious Explorations"®
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Follow Up
I retorqued the plenum nuts yesterday as PawPaw suggested. Since I had the battery disc. went ahead and checked all the sensor plugs and applied dielectric grease in the engine bay. Decided to go over the vacuum lines for good measure. All checked out until I came to the main line from the EVR to the throttle body. Looked good at the EVR but when I ran my hand down the botttom it felt real dusty. Pulled my hand out and it looked like I'd been digging in the coal bin. Took the hose off, took it inside, cleaned it up and checked it. It's ok for now but a future repl is needed. Still too cold here to do much outside, 24 deg this morning, that's a heat wave!
Rockledge, checked out the TOMCO site to learn more about the EVR as you suggested in another post on this site.
No CEL for now, runs great, blew the doors of a S-10 on the way to class last night!
Thanks
Rockledge, checked out the TOMCO site to learn more about the EVR as you suggested in another post on this site.
No CEL for now, runs great, blew the doors of a S-10 on the way to class last night!
Thanks
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Actually just did the intake gasket replacement yesterday. I'll have to wait and see if the codes don't return. Went ahead and changed the plugs replacing with Bosch Platinum Plus. Hopefully I'll see some mileage improvement. Today she's got to get to work, 3 truckloads of mulch for the better half's flower beds!
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Thanks for the heads up.
Oops, my bad, the plug change took the longest time. I'm gonna run them for a while.
Only cost me $12.00 plus the tax for the Governor and the prayers I had to say after trying to contrive myself to fit the tight confines. Not to menton the effort to remove the plug wires.
3 loads of mulch, plus 1 of compost, and 1 of topsoil.
The old gal runs fine for now, but I know I'll do it one more time!
I kind of knew I was in for trouble when I found the engine was made in Germany and the tranny was from Germany, in this American truck!
Oops, my bad, the plug change took the longest time. I'm gonna run them for a while.
Only cost me $12.00 plus the tax for the Governor and the prayers I had to say after trying to contrive myself to fit the tight confines. Not to menton the effort to remove the plug wires.
3 loads of mulch, plus 1 of compost, and 1 of topsoil.
The old gal runs fine for now, but I know I'll do it one more time!
I kind of knew I was in for trouble when I found the engine was made in Germany and the tranny was from Germany, in this American truck!
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I'm afraid you won't be running Bosch plugs very long. They don't run right to begin with, and they will wear down very rapidly. I know, Ive been there many times. You will find countless other stories just like mine. Bosch does not know the specs for the plugs for Fords. Autolite made the original plugs, so an Autolite Double platinum plug is equivalent to a Motorcraft double platinum.
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Hey Khan, thanks for the input. Gonna put changing them out for now, truck runs fine. Desalted the ol' gal today, under and over. We've had a lot of snow here and the roads I've traveled put a lot of it under every vehicle. My black asphalt drive looks white in the places where company parked. Tire rotaion and oil with filter change are next on the to do list.
Anybody got good input on the brands?
Take Care, it's gonna get bumpier out there!
One thing worth mention is to use dielectric grease on the plug boot connection and the top of the ceramic once you've seated them, before you put the boots on. Makes them easier to remove when changing, and improves the electrical contact.
The gap on the old plugs installed at the local Ford dealership was extremely beyond the range in the owner's manual.
Anybody got good input on the brands?
Take Care, it's gonna get bumpier out there!
One thing worth mention is to use dielectric grease on the plug boot connection and the top of the ceramic once you've seated them, before you put the boots on. Makes them easier to remove when changing, and improves the electrical contact.
The gap on the old plugs installed at the local Ford dealership was extremely beyond the range in the owner's manual.
Last edited by Gulliver; Mar 21, 2010 at 10:57 PM. Reason: Afterthoughts!
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