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Discussion Starter #1
OK, heres the skinny -

picked up a 2004 ram 1500 QCSB 4X4 a couple years ago. PO said he did all the maintenance, but we all know how that is. I have gone through the whole vehicle in stages, replaced all the fluids except for the trans (next couple months), and everything is more or less fine. Get back from a deployment, have to move, so I end up towing a 6K trailer about 1500 miles, then driving back 1500 miles unloaded. Get home to find out I burned 2 quarts of oil in the process (which would explain why she was a bit sluggish on the drive home).


Then I pull the oil cap one day and I notice what almost looks like water droplets. I smell it, and it smells like fuel. Ok, so I am thinking at this point that the only thing I haven't changed (picked it up at 55K, now has 84K on the odom) is the spark plugs since I hadn't had the time. Maybe the plugs are fouled, aren't burning all the fuel, and its pooling in the cylinder and getting past the rings. This in turn is thinning the oil which, when it gets good and hot, is causing it to vaporize and get sucked into the intake through the PCV system (which on the 5.7 apparently does not have a PCV valve, just a hose that goes from the oil filler nexk to the air box ABOVE the air filter...still not in love with that idea...)

So, I change the plugs, and sure enough they look like they are the OE copper plugs with 85K on them. I put in nice new plugs, the idle (which I didn'tthink was rought to begin with) smooths out, the power is a little better (have it superchiped anyway) and the mpg goes from 11 to 11.5 (this is on my daily, 7 mile commute up and down hills in the burbs at 6000 feet elevation) (oh and by the way, winter gas with ethanol sucks!)

I drive about 30 miles on the new plugs, figure the oil has gotten good and warm since then, so if any old fuel was left in it it would have burned back off and things should be back to normal. Pull the oil filler cap and - more droplets. Still smells like fuel...

So, here's my question -

Is it the MAF sensor got all crudded up, and the increased voltage is telling the ECU to run richer thinking there is more air...
-or-
Are my rings shot and I need to pull the d**m engine and rebuild it before I put a bunch of fuel in the oil system and have real issues...

Or is it something else that I'm not thinking of? I know the TB was pretty dirty when I looked in there when I was doing the plugs, but the little sticker on the side of the TB said "DO NOT CLEAN." I'm thinking they were referring to the MAF (or Mass Volume, whatever it is) sensor that plugs in right there.

Anyway, I'm getting frustrated:4-angermax: that this problem is not going away. Wondering if I should pull the TB off and clean the hell out of it, maybe pull the intake too and clean that (although that might require messing with the fuel injectors) or is there maybe a lazy O2 sensor that could be throwing off the ECU?

Long post, but I wanted to give a good description of the problem. Hope y'all are having a good start to the week. It wasn't the best monday ever, but it's over.

Thanks

-M.
 

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I'm not a certified mechanic or anything but I'm pretty sure that oil and fuel are not meant to mix in any type of gas automobile engine (2 stroke engines yes, but not in 4 stroke). I don't believe it's a MAF sensor telling your engine to mix fuel and oil. I think your piston rings are shot or there is another seal that has gone bad that is allowing fuel from the combustion chamber to leak into the crank. Were your old plugs black and oily? If so this would be an indication that your piston rings are bad and allowing oil to pass and clog up the firing of the spark plugs.
 

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Discussion Starter #3
No, fuel and oil are not supposed to mix in a 4-stroke engine, but the MAF sensor tells the ECU how much air there is coming into the cylinders. It does this by sticking a wire out into the air stream in your intake, sometimes just after the airbox (like in my wifes sedan) or in the case of the 5.7 just after the throttle body plate. The more air that passes over the wire, the more voltage required to keep the juice flowing through the wire because the air mass over the wire is greater. The increase in voltage tells the computer how much air there is, so it can measure how much fuel to inject.

Now, if your MAF gets dirty, it requires more voltage to keep the juice flowing, tricking the ECU into thinking there is more air than there actually is, and the ECU responds by adding more fuel to avoid a lean condition. This actually results ina rich condition, and my question is whether or not, if this is occuring, and I had cruddy spark plugs to boot, I could get so much fuel into the system that I could actually get fuel pooling in the cylinder. (And yes, the plugs were black, but the air box hose was oily, telling me that the PCV hose was breathing oil into the intake, so I think that was the culprit there).

Now, fuel carburetion is an interesting thing - ideally, there should not be any liquid fuel in the air charge, only atomized fuel. Liquid fuel will not combust in the cylinder, because it's not mixing with the air properly. So if there are actual droplets, you could get pooling, and if the rings have too much clearance between them and the cylinder wall, then I'm wondering if its possible that the fuel is then leaking (small amounts mind you) into the crankcase, thinnning the oil and perpetuating the cycle. Of course, I don't know if th eMAF sensor operates continually, or just when the engine is warming, and then sends the ECU into closed loop operation where it just operates off the O2 sensors or something...that's beyod the limits of my understanding at the moment.

If this is the case, then there are 3 potential separate problems:
1) bad plugs that don't burn efficiently
2) a clogged MAF sensor that is tricking the ECU into running rich
3) loose piston rings that are not sealing the cylinder efficiently, made worse by the low compression of crappy plugs (there are usually 3 rings if I understand correctly, and they seal the cylinder under compression of the combustion, they don't seal perfectly when the engine isn't running.)

I changed the plugs, so I took out that variable. The MAF sensor cant be cleaned, but it can (I think I read on here somewhere) be replaced for fairly cheap.

The last thing is probably to do a leak-down check, to see how the cylinders are sealing.

So, a few more questions for the group:

1) on the 5.7, can you replace the MAF (or Mass Air Volume, if that's what it is) sensor? If so, any pn's or prices?
2) any tips for cleaning the TB while I've got the thing apart again?
3) any tips on doing a leakdown test?

4) Is anyone else having this problem?

As for having another seal be blown, I can only think that maybe the head gasket went, but if that were the case, the coolant would be disappearing and the oil would look like a milkshake. So I think the head gasket is ok, but that's a guess, like much of the rest of my post.
 

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1) on the 5.7, can you replace the MAF (or Mass Air Volume, if that's what it is) sensor? If so, any pn's or prices?
My experience says just about any sensor can be replaced. Try cleaning it with electrical contact cleaner first.

2) any tips for cleaning the TB while I've got the thing apart again?
Brake cleaner and a brush. Do NOT use carb cleaner. It leaves a film.
3) any tips on doing a leakdown test?
Do a search on it, Ramtech did an excellent detailed post on it a while back.

Forgot one thing. If your rings were gone, you'd be smoking under acceleration. Also while you've got things apart, put a Catch-can on it. It goes in-line on the PCV. You can do a search for that too for details.
 

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Ok, guys, first things first. Throw out the MAF sensor idea - Dodge doesn't use one on gas engines.

Onto the droplets. Chances are they're just condensation which is common in aluminum engines. From what I've read I gather you haven't yet changed the oil since doing the plugs. Now might be a good time to do that and make sure you use the correct weight.

A dirty throttle body can be cleaned providing you do it the right way. There's an ETC cleaning procedure here - http://www.ramforumz.com/showthread.php?t=46764

If you suspect fuel is getting past the rings, I recommend doing two things. First, check for a leaking injector by attaching a fuel pressure gauge and turining the key on and off a couple of times to build pressure (range is from 54-64psi) and the turning the key off and clamping off the fuel line between the pump and injector rail. If the pressure drops to 35 psi in less than 5 minutes, you likely have a leaking injector. Second, perform a cylinder leak down test to see if the rings are worn. There's no special tricks to this but it is very time consuming.

Lastly, a lazy upstream O2 sensor is prone to causing performance issues and poor fuel economy but it won't cause the problem you're having. A lazy sensor can set codes P0133 and P0153. Running rich will set codes P0172 and P0175. Setting only one would indicate a leaking injector in that particular bank.

Best of luck in diagnosing the problem and feel free to ask for any info you need.
 

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Discussion Starter #6
Ramtech/Rootbeer, thanks very much. I was not aware that aluminum engines were prone to condensation - I would have guessed it would all burn off when the oil warmed up, basically get turned back into vapor and get sucked through the PCV system.

As for the MAF sensor, I've heard that before (that dodge doesn't use one on their gassers). What is the sensor right at the throttle plate? I'm going to guess a throttle plate position sensor? If so, do I just cover that up when I'm cleanign the TB? There is a sticker there on the side of the TB right where the plug is that says in big bold letters "DO NOT CLEAN", so I was thinking they meant the sensor was sensitive. Certainly a TB could always use a good cleaning.

I have Brakleen, is that the same as the MOPAR version? I use Brakleen quite a bit to clean gasket surfaces, and it's not supposed to leave a residue.

I will try the fuel pressure test and the oil change - I think RB is right, if I had loose rings, then I'd be having other issues as well I would think, like blow-by at high RPM and smoking coming out the exhaust from the burnt oil, which I don't have. I was always concerned about that since I towed that trailer over the continental divide, didn't realize my oil was a bit low, and I had the thing going at 6K rpm when I had to lug up the hills (that elevation really saps the power...) I have periodically wondered if I might have damaged it, but I doubt it given the consistent power and the mpg.

Ok, I will work on those projects and get back to you. Thanks again for the help fellas.

-M.
 

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The brake cleaner you have should be just fine. The important thing is to NOT use any kind of carb or TB cleaner because it can damage the electronics in the ETC system. Brake cleaner won't harm the electronics. The sensor you refer to is a TPS.
 

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Discussion Starter #8
ETC? What is the ETC system?

Also, for the fuel injector check, I'm assuming I need:

1) a Fuel pressure gauge with a schrader valve for the schraeder valve on the fuel injector rail?
2) a hose clamp - being that its fuel injection, are the fuel delivery lines just a higher psi-rated rubber hose, (up until the manifold) r are they hard lines all the way from the tank?
 

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Discussion Starter #9
Also - what does the aluminum have to do with promoting condensation? Just curious if anyone knows. I actually didn't even know the 5.7 was an aluminum block, I figured it was cast iron.
 

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The 5.7 is an iron block with aluminum heads and a plastic intake manifold, Condensate will form under your oil cap when it get cold out side when the engine is cooling down this is normal. Whats not normal is if it's there after you have been running it and it is a full temp for several miles or about 30 minutes.
 

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ETC? What is the ETC system?

Also, for the fuel injector check, I'm assuming I need:

1) a Fuel pressure gauge with a schrader valve for the schraeder valve on the fuel injector rail?
2) a hose clamp - being that its fuel injection, are the fuel delivery lines just a higher psi-rated rubber hose, (up until the manifold) r are they hard lines all the way from the tank?
A fuel pressure gauge and a pair of pinch off pliers will be needed for the injector leak test. There should be a section of flexible line near the engine to close off.
 
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