P0174 Error code help

[sman83]

Hello all this is my first post to the webiste been reading it for awhile now and have added it to my favorites.

I am not a expert by far, maybe a novice I wouldnt even call it that though.

I have read through the website and have seen some similar problems related to mine. I just recently changed the IAC which fixed the startup problems. Once that part was on I reset the PCM and noticed the engine was idleing high and would shimmy on cold starts. The idle would go up and down if I shifted from R to N to D and so on. I cleaned the MAF and nothing changed. The air filter is a nice paper one and isnt dirty.

I would like to change the intake manifold o rings? but I have no idea on how to do this or what I am looking for. Here is my vehicle:

1999 Mercury Mountaineer
V8 5.0L AWD

I also found this on www.carcomplaints.com very nice website listing the most common problems with vehicles.


TSB #01205 -- SOME VEHICLES MAY EXHIBIT VACUUM OR AIR LEAKS IN THE INTAKE MANIFOLD AND / OR ENGINE SYSTEM CAUSING DIAGNOSTIC TROUBLE CODES P0171 AND OR P0174. *TT (NHTSA ID #627927, OCTOBER 15 2001)

Any help would be much appreciated. I visit this site daily so I will see your responses.

Thanks !

 

[NHale623]

Do you have that code?

 

[sman83]

Sure do

Yes I have that code. It popped up about four days ago.

Will it hurt to drive the vehicle with it like that? It will be awhile before I can get the gasket and o rings changed.

 

[mportpwr]

P0174 is a lean condition on one of the cylinder banks, Dead Link Removed

Do you hear any knocking in the engine? Some describe knock as if marbles were bouncing around inside one of the cylinders.

A lean condition could be caused by the following:
Dirty MAF
Perforated intake manifold gaskets
Poor fuel pressure
dirty injectors

You said you cleaned the MAF, so it shouldn't be that. A bad gasket could have stuff blowing around inside the engine bay or produce a whistling noise. This happened on a Ranger I used to own with a 4.0 V6. Poor fuel pressure would run lean on both banks, and cause other noticable problems. Dirty injectors could be the culprit, but you'd notice performance lagging as well.

Has your gas mileage decreased suddenly? This would mean that the PCM was dumping extra fuel into the cylinders to combat the lean situation.

I would not drive around a vehicle running lean for too long, and would not at all if I could detect knocking. That is a good way to burn up a motor quick.

The gasket rings could be be shot. Being a '99 your truck is now 8 years old. Do you hear any odd noises coming from the engine, or notice that you are seeing deposits inside the engine bay? Are you burning any oil or coolant?

I will admit that I am not the most familiar with the 5.0 V8, but these are things that I noticed when my Ranger blew its' intake manifold gasket.

Hope I've been some help!

-Kevin

 

[joshfig]

How long does it take to trip the code after you reset it (either by clearing it or removing the neg battery cable)?

I have the lean codes pop up every once in awhile when its cold, but it will go several hundered miles to thousands of miles before tripping again. Point being, I have something barly out of spec (only when it is cold), so probably not worth bothering with.

If you reset it and it comes back after 50 or 100 miles, dive further. If not, don't worry about it.

 

[sman83]

No other noises

I have listened to the engine many times and havent heard any other odd sounds.

My gas mileage seems to be normal. I just drove 3 hours on thanksgiving with out any problems.

I had reset the PCM so the light would go off, but it came back on within 2 days or about 50 miles. It is also getting colder here. The previous owner did not have this problem but they lived in Arkansas it doesnt get cold like it does here in Illinois.

Would a month be ok to drive on? I am a broke college student and have to wait for student loans to come in, so I can pay for the repair of the manifold, if that is it.

 

[joe doe]

i have the 4.0 v-6 and the same codes for about 2 months now ...i been driving it but i dont hear any pinging so i feel pretty safe about it .i am however getting the gaskets done next week probably.

 

[gfisch]

How long does it take to trip the code after you reset it (either by clearing it or removing the neg battery cable)?

I have the lean codes pop up every once in awhile when its cold, but it will go several hundered miles to thousands of miles before tripping again. Point being, I have something barly out of spec (only when it is cold), so probably not worth bothering with.

If you reset it and it comes back after 50 or 100 miles, dive further. If not, don't worry about it.

You have any idea what is causing it on yours? I have a similar problem and it comes up without fail every year since I got the truck when it starts to get cold in october/november and then don't see it again until next year after I reset it.

 

[joe doe]

my understanding is this ....when it begins to get cold out the orings in the intake start to shrink from the cold ...this allows them to leak ...when the car warms up they expand again allowing the seal to form better.it will probably always do it in the cold climates until you get it fixed.i will be getting mkine done very shortly and i will post my results for all to see.