I changed the head gaskets on my dad's 2001 Sport Trac and when I started it up afterward, oil began spraying out of the exhaust manifold mostly on the passenger side but also a little on the driver's side. I'm showing 150 psi on all cylinders. I removed the intake manifold and found oil mostly in the back two cylinder ports. I also removed the passenger exhaust manifold and it seems that only cylinder 3 was the one spraying oil. I have already checked the PCV hose and also removed the hose to start it and it was still spraying oil. I'm assuming it's bad piston rings, but it was not doing this before (I don't think). Maybe before the oil was being burned up in the catalytic converter and the only reason I noticed was that I started it up before putting the cats back on. The new oil I put in already smells strongly of gasoline. I'm assuming I'll have to remove the engine for the piston rings? I've seen videos of people doing it without removing the engine but not this engine. Also, when cranking the engine, I can hear a strange sound. The best I can describe it is a "glug, glug, glug" sound coming from the oil pan. Almost like the oil is too full and the pistons are hitting it, but the oil level is almost below the low marking on the dipstick. I have also put compressed air in cylinder 3 and I can hear air coming out of the crank case, but nowhere else. I also hooked it up to cylinder one and the sound was nowhere near as loud coming from the oil tube, but it was still there. I know some air will always leak but even cylinder one seemed to be leaking a bit too much, but cylinder three is definitely having issues.

 

Problem solved. It was actually gasoline mixed with carbon deposits. I was running the engine with only the exhaust manifolds on while stupidly leaving the O2 sensors in the oxygen rich environment leading to extreme over-fueling. Thanks for all the help! (sarcasm) I feel like I was ignored due to my double post.

 

Hmm, I didn't see either of your original posts until seeing this thread today. I apologize for no responses, but I guess it's kind of a non-issue at this point. When I read your subject prior to opening the thread I thought, "Maybe it's just condensation mixed with carbon/exhaust byproducts." Well, such a response would not have been too far off I guess.

Do you have a theory on why cylinder #3 sounded so much like air was blowing in to the crankcase but all seems well now? Were you using a cylinder leakdown tester or just running compressed air straight in to the cylinder? If a leakdown tester, what percentage of air was leaking for cylinder #3 versus any other cylinders you tested?

-Rod

 

Sorry no one replied to your post here, but glad to hear you resolved the problem; welcome to FTE!

Steve

 

I was thinking that condensation could be a part of it. Would a rich mixture create more moisture than lean? I was using a hose from a compression tester with the schrader valve removed that I adapted to fit the air compressor. I only tested cylinders 3 and 1 and there was a pretty significant difference between the two (now that I think of it, the air pressure was not being regulated so that could very well explain the difference). The thing is, the truck ran fairly well before I started the project (oil and coolant were mixing with each other). I don't know how I could have possibly damaged the rings by doing a head gasket job, so it must have been like this before. I know that SOME air going through the crank case is ok, but I'm not sure how much that is. Another possibility is that the valve seals may be more worn out on #3 which would explain the air coming from the oil filler tube. Now that I think of it, the sound sounded too close to come from the crank case so it must have been from the valve cover. The sound was also coming from the dipstick tube, but just barely. Or I guess maybe it wasn't at TDC and the intake valve was open, which in turn could go through the PCV hose to under the valve covers. It very well could have been oil spraying out, but I figured I'd better put it back together and give the gas theory a shot before removing the heads again (to check for cracks) and having to purchase new gaskets and bolts.

 

Well, in a fully functioning exhaust system a rich mixture would create more moisture since the catalytic converters convert the unburned hydrocarbons to water, but in your case, where the exhaust was not connected, the "moisture" from a really rich mixture may have just been raw fuel?

I don't know that I'd worry much about the difference in perceived air flow between cylinders 3 and 1 at this point. You were searching for a problem and there were a lot of variables in your setup, so just enjoy the current success.

-Rod

 

After getting everything put back together, I decided to try to fire it up before installing the exhaust just to be sure it'll fire and it did for a couple seconds, then it backfired (very muffled sounding backfire, almost like a potato gun or something like that). Tried to crank it again and it wouldn't start. At this moment I look up and I'm like "that doesn't look like where the smoke was coming from before". I thought for sure I blew a head gasket, so I sat there, defeated for about 10 seconds and decided to go check on the ever increasing amounts of smoke. Well, I was met with a small engine fire. It was very easy to extinguish with a garden hose, however, so there is no lasting damage. I think it was just gas burning on the surfaces that were sprayed. This I believe defeats my O2 sensor theory on why it is overfueling, since the ECM was reset before this and the engine would have been in open loop since it was cold. The fire does very much confirm that it is fuel and not oil. After a couple more cranks, I reached into the manifold, and sure enough, the substance was almost straight gasoline instead of the oily substance from before so I'm guessing whatever deposits were in there before were mostly dissolved. The only thing I've done since then is check the fuel pressure and it's an even 60 psi. I assume this is probably correct, but I should probably check on that spec before drawing conclusions. My next course of action would be checking for a stuck open injector. I was not able to test the pressure at the rail because I don't seem to have the proper adapter, but being a returnless system, I was able to test directly after the fuel filter with a T-fitting. My biggest fear, and probably most likely answer is that the timing slipped on bank 1 for sure and maybe bank 2 as well, but most likely to a lesser extent, if at all. The fire was on bank 1 by the way. I do have the required timing kit, so it was set correctly at one point and the problem DOES seem to be getting progressively worse. It would make sense, since bank one's camshaft sprocket bolt is much harder to properly torque with the engine in the vehicle. Improper timing would explain the raw fuel in both the exhaust and intake, and most likely explains the backfire/fire. So, unless anyone has any other suggestions, I'll be tearing down everything to the camshafts for the fourth time lol. I'll stop and check the injectors before going any further though.

 

I just now realized that the camshaft bolts are TTY and not reusable. Just goes to show what happens even if the bolts are torqued right. That is, assuming the timing is the issue...

 

I'm pretty sure your dad's 2001 has 4-wire heated oxygen sensors which means there really isn't an open loop mode anymore. The H02S enables the PCM to get meaningful data during normal assembled operation, so you're earlier theory about the exhaust being disconnected still holds some merit.

-Rod

 

What I was saying is, I had just hooked up the battery and I even touched the pos and neg wires together to reset the ECM so that when it started up, it wouldn't be running off the learned rich table from before. It started spraying gas instantly, so even with the heated sensors, it shouldn't have been in closed loop yet. I'll definitely hook up the exhaust and get some numbers from the code reader before I melt the cats if it's still running rich. The timing makes sense out of the moderate amount of gasoline in the intake and the exhaust. Could even be a combination of the two problems. I know the timing was perfect after I set it and it just seems to run different. It almost has an uneven sound to it if it even starts. It's just been getting progressively worse and that worries me since this is an interference engine.

 

If you have a compression tester or decided to purchase a leak down tester you could get a pretty good idea if the timing is still okay without tearing the engine apart again. I personally wouldn't count on disconnecting the battery and touching the battery cables together to full reset all the fuzzy logic in the PCM. Resetting the KAM using a scan tool would be the preferred method. Some of the different running behavior might just be due to the engine having a drastically different air fuel mixture than what it was expecting and it's trying to figure out what it needs to do to compensate. It's always nerve-wracking to start up an engine after so much work, and your senses are naturally heightened, checking for anything that seems abnormal. Sometimes that can really play games with the mind.

-Rod

 

Sorry for disappearing like that on everyone. Had a touch of the flu. Anyway, today I decided to take the passenger front tire off to get a better look at the OIL leak. Yes, oil, not gas, oil. I thought the oil was coming out of the exhaust because it was leaking above where the exhaust blows out, so I'm sure you can see my rookie mistake. As soon as I had the tire off I had a perfect view of the leak and it turned out easier than I thought and it was free to to fix. I feel stupid even admitting to it, but I left the crush washer off the rear tensioner, leading to a massive oil leak. Washer has been replaced, tensioner primed and torqued to spec... and not a single drop leaking anymore. I will have the a chance to look at fuel trims later as I'm sure there will be issues from the oil soaked O2 sensors, but for now, I have to get the exhaust bolted together tightly so that it seals and doesn't **** off the neighbors more than I have already. However, the engine seems to be purring like a kitten but obviously much louder. It did quiet down as soon as I took care of the leak at least to the point where it just sounds like it has straight pipes or maybe a glass pack. The exhaust pieces are very messed up because I had to cut seized bolts right out of the cast iron, leaving a U shape for the bolts rather than holes, but I think with some effort and some exhaust putty, I'll get it figured out. So I think we can finally put an end to this thread. Thanks for everyone's help. I really appreciate it. And remember...USE YOUR WASHERS!!!!

 

Thank you for the follow up post on what you found. I'm glad to hear you got the leak resolved!

-Rod

 

Ok so some new problems have surfaced. I have the exhaust back on and it is sealed (no excessive noise), and I also replaced both upstream O2 sensors. I started the engine to check fuel trims and noticed that there seems to be a constant misfire, but I'm not getting a misfire code. Short term trims on Bank 2 were perfect, but Bank 1 started at 26% and climbed up to 42% before I shut off the engine. The only code I have is a DPFE code which was there before I started the entire project. Using my stethoscope, I narrowed the issue down to a hanging injector on cylinder 1. It was barely clicking and all I could hear was a "whoosh" sound like it was not closing nearly fast enough. Like it opens nearly normally, then slowly slides closed or something. The resistance checks out at 13ohms, so it must just be dirty. I assume that it's so rich that it wasn't igniting, causing the lean code. That is not the only issue. I also noticed something new or something I didn't notice before, but most likely would have if it was there the whole time. There is now a moderate amount of white smoke coming from the exhaust. I know this screams coolant leak, but I've also read that raw fuel can cause this (mostly diesel but I've read about gasoline causing this as well), especially in the case of a stuck open or hanging injector. Unfortunately, the smoke smells what I imagine coolant would smell like. After killing the engine, the remainder of the white smoke slowly flows out of the tailpipe and falls toward the ground. Kind of like dry ice fog. If anyone's ever seen what vapor from a vape pen looks like, it's nearly identical. Since the vape pens contain propylene glycol and antifreeze contains ethylene glycol, I imaging it has to be coolant. I did however look into the coolant reservoir and there were no bubbles while the engine was running and last time I did the compressed air leak test, there were no bubbles. Today I retested compression on all 6 cylinders (only dry). From 1-6, the results were 165, 165, 155, 210,210,220. The specs that I found say no lower than 100psi and no greater than 70 psi difference between the highest and lowest, so I'm sitting on the edge of normal. It seems very strange to me that one bank is so low and the other is very high. For this compression ration, 220 seems almost too high. So I was thinking that the only thing that could cause such a difference between the two banks would be a slipped timing sprocket like I was worried about before and never checked. This would not explain a coolant leak though. Tomorrow I'm going to improve my set up so that I can control the compressed air going in to the cylinders better than I could before and see where the compression is going. Last time I did this, I am certain I found DTC on cylinder 1, but air was rushing out of the intake, so I had to turn it until I could hear that both valves were closed. I can't remember how much I had to turn it, but it was at least an 1/8 to 1/4 turn. First I guess I'll have to take care of cleaning the injectors with an ultrasonic bath which I still need to order, but I'll also check the timing while I have the intake off. I'm really starting to hate this engine for how much work it takes just to get to the injectors. It takes me about 15 mins on my Suburban to get to the injectors, while it takes about an hour and a half on this one. I know that I could just loosen the intake plenum and try to push everything out of the way, but I'd rather not have to struggle. I could probably get the heads off my Suburban also in the time it takes me just to get the injectors off the Sport Trac. Anyway, probably shouldn't be bashing Fords and praising Chevy here, but what is with the complexity of this engine? It definitely has nothing to do with reliability, that's for sure.

 

I don't have much for answers here, but a few comments. Higher fuel trim numbers suggest the ECM is requesting an increased duty cycle from the injectors in response to a lean condition. That is inconsistent with what would be expected if a fuel injector were not closing quickly enough.

Excessive raw fuel in the exhaust could cause a gray exhaust, but white typically indicates water or coolant. It can be difficult to tell the difference between gray and white, but the smell is quite different. So if the exhaust smells more like coolant and less like fuel, I think you're on the right track to suspect a coolant issue. I'm unsure if coolant in the exhaust would cause the O2 sensors to report a lean condition. You might want to read up on that. Coolant in a combustion chamber will do a very nice job of cleaning the carbon out of the cylinder and cleaning (as well as possibly discoloring) a spark plug. When you had the plugs out for the compression check did you happen to notice if any of the plugs looked different from the others?

-Rod