Lean codes bank 1 and 2

[blue oval guy]

So anyone who knows the Triton motors knows that high mile motors will sometimes develop air intake leaks due to failed intake manifold gasket or cracked intake manifold (since they are made of composite)
The proper fix is to pull the manifold and replace with new piece and gasket obviously. Has anyone ever gotten away with torquing the intake bolts down a little more to buy some time? Mine had a little over a 1/4 of a turn wiggle room to snug down on each bolt? I'll clear code tonight and see if codes return.

 

[Andy J]

When i worked at ford they always told us to never overtorque the intake manifolds. They said it will either crack the manifold, distort it, or crack the gaskets. The specs also said to retorque the manifold once the engine had gone through a few heat cycles but that was only when you installed new gaskets or a new manifold

 

[Andy J]

I would be more inclined to think you have a vacuum leak from one of the lines or pcv because when manifolds crack or gaskets fail its usually going to only happen on one side at a time. Lean on both banks means that the leak is occuring on something that both banks have in common like a throttle body gasket, pcv line, or vac line.

 

[blue oval guy]

Thanks for the info, i have the dreaded P0171 and 174 codes. Am i jumping the gun assuming it's intake manifold? can MAF sensor cause lean codes too?

 

[blue oval guy]

Thank you! I'll double check all my vac hoses first, I just did plugs about 2 weeks ago, i probably disturbed something in the process.

 

[Plati]

http://www.expeditionforum.com/threads/obdii-reader.34543/

 

[1955moose]

Blue oval, if you've been out here awhile you know the two most common issues with those codes are pcv elbow, and maf sensor. Obviously their can be a myriad of other items, but that's the jump off point! And yes you most definitely disrupted something swapping out plugs. Welcome to mechanics 101! Fun ain't it!

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[Hamfisted]

Best way to find it is with a smoke machine. You'll find every leak within about 15 seconds. Rather than guess, or just throw money at it. Typical leaks don't show up using the carb spray method because the computer can compensate too quickly for you to hear a definite rpm change. If you took it to a professional shop they would use a smoke machine.Typically people disconnect or jar loose either side valve cover tubing. When I did my plugs last year I inadvertently left the breather hose out of the driver's side valve cover, and of course, it threw the lean codes. Didn't see it just looking around with a flash light. Found it in a few seconds with the smoke machine I had. Lesson learned....


https://www.ebay.com/itm/282907595552?hash=item41de9b5320
https://www.ebay.com/itm/282907595552?hash=item41de9b5320
If you end up needing to replace the whole vacuum christmas tree line you can find it over on ebay for about $65.

https://www.ebay.com/itm/2000-2004-...3Z-6C324-AA-/201301474618?hash=item2ede80bd3a
https://www.ebay.com/itm/2000-2004-...3Z-6C324-AA-/201301474618?hash=item2ede80bd3a
Or you find just the elbows in the Dorman assortment pack at any Auto Zone or Advanced Auto store for about $12 .

 

[blue oval guy]

Thanks for all the feedback, I will go after the obvious things first and then let them use the "smoke" test, you are right on, when we were scratching our heads on explorer 4.6, they found issue within 10 minutes using the smoke approach. Just hoping i dont have have to pull intake off, lots of stuff to remove before intake pulls off...

 

[1955moose]

Their are articles here to build your own smoker, but at $150.00 you might want to buy one. Or logical choice find shop to do it cheap, weigh out if you fix, they do, or its so bad you put $1.99 for sale sign on it. If you do yourself, we always recommend, that option, smoke thru brake booster vacuum hose. Keep in touch!

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[DontBeJeff]

Don't be afraid to test and re-test. I have those two codes, and all smoke tests came back without a leak, and for a while so did the fuel pressure test. After a while, something will start to show. Don't just shotgun parts - I have learned that while I did replace some hoses that where definitely worn, none of them fixed my issue, and some parts that seemed good I replaced anyway and still no luck. In the end, it was the fuel pump that was going bad, as doing test over test I noticed that it kept getting worse, and because I don't want to do more work then I should, got a mechanic to verify that it was indeed going bad. Have that as a weekend project to replace it here in a few weeks, so hopefully that fixes my problem!

 

[blue oval guy]

Thanks for feedback, yes i was going to start with replacing some vacuum hoses, namely PCV elbows and hoses on both sides. What was the test for the fuel pump, just a gauge reading at the fuel rail while at idle? Thanks.

 

[Big Brian]

Just spray a little carb cleaner around the areas where you suspect a vacuum leak. If you have one the engine will speed up slightly when you hit it.

When I was doing this for a living there was no such thing as a smoke machine. We would always find them with carb cleaner.

But we did not have computer controlled engines back then either.

But if you have a decent leak it will show up with carb cleaner

Not that the smoke machine isn't a good idea, I just don't think its needed most of the time

 

[DontBeJeff]

As for the fuel pressure, on the passanger side bank's fuel rail, there is a schrader valve to put a fuel pressure gauge on. Look up the fuel pressure for the engine you have. I have a 5.4, so getting closer to 30psi and lower is starting to show that it was going bad for me. Also, it didn't hold pressure after turning off the engine. Not a big deal for a lean code, but it is also a sign that the fuel pump is needing replacing in the long run as it should hold whatever pressure it was at when it was turned off.