So I started a thread a week or two ago, thinking that the white smoke coming out of my tail pipe was a slow head gasket leak.

I checked the coolant reservoir, and it was at the very bottom of the reservoir. I filled it up to the MIN mark. Cranked it up and put a rubber glove where the cap would go. Left it there for a couple minutes, but it was definitely not filling up.

So.. I get the bright idea to just look at the CEL codes!! I'd been getting a common code before my PCV system was replaced, and I got it a month or so after it was replaced. So I kinda thought it was the same thing. Actually, I think it was the same thing once or twice after the PCV system was replaced, so I just got tired of resetting the light.

It's been on for quite a while, but it's only been running rich for a couple weeks. I parked it because I thought there was water in there, which isn't entirely out of the question. I wasn't showing any milk shake before cranking it. I cranked it and let it run for 10 minutes, seeing rich smoke (definitely *not* smelling like coolant). Just went to check the oil again, but I'm seeing the milk shake. Wiped it off and checked it immediately afterward. No milkshake. But that's probably an entirely different story after I crank it again.

I do need to change the oil, tho. I actually didn't replace the oil right after doing the PCV change, as is suggested.... but I did use an air compressor to get any gunk out of the passage ways. So I was hoping that an oil change wasn't immediately necessary.

Anyway.... any clues as to why I'd be running rich?? Leaky fuel injector??

A code P0172 may mean that one or more of the following has happened: The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters can cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry. There could be a vacuum leak. There could be a fuel pressure or delivery problem

 

Try clearing the computer and see what it does. If its still rich its probably a fuel pressure regulator or a leaky injector.

 

Here are the facts:

RICH OIL
=======

-- Replaced MAF sensor almost as soon as I bought the car. Less than 2 years ago and not all that many miles.
-- Replaced PCV system several months ago (however I didn't change the oil, as recommended ).
-- I'm guessing that means a leaky injector or bad fuel regulator is the only real culprit? I've got one of those awesome code scanners that hook up to the Torque app on your phone, thru bluetooth. And all the real-time readouts seem normal to me, but that's just how the ECU is seeing things... not necessarily how things are really happening??

MISSING COOLANT
==============

-- Replaced heater core over a year ago with the one with a lifetime warranty. Plus, my carpet's still out, so I can definitely tell it's not leaking from there.
-- Any milk shake-like oil seems to be right in the dipstick tube. After wiping it off once and running it again, it seems to just have plain ol' oil. So any condensation in there is minimal.

OTHER INFO
=========

-- I am also getting oil on top of the engine, under where the spark plug cover would be.... however, I never put the spark plug cover back. So, I'm thinking the PCV problem wasn't completely fixed since I didn't change the oil?? I do lose a little oil now and again, but not nearly as much. I've also yet to replace the camshaft gaskets, since I haven't done the timing belt / water pump job yet. But oil on top of the valve cover????? REALLY??
-- I cleared the code, and it's still putting out the same rich exhaust. I wonder if an idle relearn could help reset the ECU to being less rich??
-- The Check Engine Light has still not returned, even tho I started the car for a minute or so and stopped it, at least 3 times. Thought it would return, but it hasn't yet...

Is there any chance that changing the oil is going to lean out my mixture?? Might help with getting rid of a little condensation... but does condensation in oil lead to a rich exhaust??

 

Wooooooooooooo, this thread is very confusing to me. From reading it a few times I think you are complaining about 3 problems.

Is the car turbo or NA?

PCV Info:
- The reason you change the oil immediately after doing the PCV job is that you may have pushed debris down into the oil pan. If so, this debris can get sucked against the oil pick up screen and cause low oil pressure.
- Did you do the job yourself or did someone else do it? If you did it, did you use all OEM parts? Using other parts may result in parts deteriorating in the matter of months. A broken, torn, or deteriorating elbow can cause a vacuum leak which will cause a P0172 error code.

OIL ON TOP OF THE MOTOR:
- This can be cause by a leaking oil cap seal or worn oil cap. If it's not sealing good, blow by will cause oil to seep past the cap seal and get on top of the motor.
- Do the PCV glove test to see if the system is still plugged up somewhere.
- If you do the PCV glove test and the glove raises, there is a chance that you are having piston blow by which will cause oil to get past the oil cap and smoke out the tail pipe. You can do a compression test to see if the motor is worn and causing blow by or smoke.

COOLANT ISSUE:
- I think you mentioned coolant because of smoke out the tail pipe and gunk on your oil dip stick. If your coolant level is steady I doubt you have a head gasket issue.
- If you posted about gunk on your oil dipstick somewhere else, people likely told you NOT to worry about it due to condensation. And likely suggest that you drive the car down the freeway for 30+ miles and see if it cleared up.
- The quickest way to check your oil for coolant is to drain it in a clean drain pan and see what it looks like there, if fine, pour it back in the motor.

OIL CONDITION:
- Not sure what you have going on there but if you are saying that you have not changed oil in a couple of years... what are you waiting on? The owners manual suggest that oil is changed at least every 6 months. Anything beyond that is asking for engine trouble.

TAIL PIPE DISCHARGE:
- If the car is cold, it will have condensation discharge.
- If the head is original, you likely have worn valve stem seals which will cause the motor to smoke, especially if you are running thin oil.
- If the car is running very rich, it can also smoke.

RUNNING RICH:
- This is a condition that you want to correct ASAP. Running rich can burn a valve.
- It is likely caused by a vacuum leak.
- If something was wrong with the MAF, the car would likely toss a MAF code.
- You should check all of your intake tubes and vacuum lines for damage and make sure they are connected properly. It is likely not a GROSS leak or it would not run good.
- As for the code, a brief start and shut off will usually not allow the code to return. You will likely have to drive a little, as much as 50 miles.

 

Rspi makes some good points. The best advice I have with this is to, first and foremost, change that oil. Then do a compression test. Doing both will tell you ALOT about what's wrong. If you pass the compression test then the "glove" test wont be needed. Another thing this could be is valve seals. bad rings or valve seals are likely to cause smoke in the exhaust and MAYBE a rich condition.

I don't quite see how you have ruled out a head gasket here. If I had traces of water on the oil, smoke in the exhaust, and missing coolant that I can't account for I would be leaning at a bad head gasket. Those are text book indications of a head gasket problem or warped head.

 

I had this code for a while and could not figure it out until one day it hit me. I replaced the PCV system to but for got to put the rubber/metal seal in where the pcv tank connects directly to the lower motor. There was an old one on there, I took it off and put a new one in, P0172 was gone!!! Maybe you forgot the seal to, just a thought.