Nick,
What do the spark plugs look like for cyls 3 & 6 ?
Do they show any signs of oil contamination?
If they do, oil is getting into the combustion chamber , if not, oil is getting into the exhaust passages through another path.

The diagram I was hoping to locate is usually in the shop manual and I couldn't find anything for that engine anywhere on the net. Maybe someone has one or knows where to find one. It shows the path of lubricating oil from the sump to the filter then up to the rods and mains and on up to the cams , followers etc. If there are any special bolts to allow oil to pass it will usually show that..

 

I can't remember where in the AllData manual I saw the oil screw mentioned, but I know it's tight if that's what your concern is. Plugs 3 and 6 definitely have oil on them. The others are completely dry.

 

I am wondering if some parts of the rear tensioner are interfering with the oil flow..
It may just be time to pull the engine and go the full route.

 

What do you mean full route? Money is definitely an issue here, but too much money has already been put in to it to give up. To pull the engine, I still need to buy a hoist and a stand, plus the rings and new crankshaft bearings. How would the rear tensioner be interfering with oil flow? Should I be able to smell exhaust coming from the oil fill tube when the engine is running if the rings are bad? Could there be excessive crank case pressure or something forcing the oil through the rings, even if they aren't bad? Sorry if I repeat myself...I have this question posted on another forum.

 

I believe we tried to examine the possibilities and keep coming up with the same answers.
The miles on the engine
The amount of air that is going into the crankcase at #3 cyl,& 6
The fouling of the plugs with oil for cyls 3 & 6
We tried to look beyond those indications to try to rule out any things that might have been overlooked
I cannot think of any other things to check other than the way the rear timing chain gets its lubrication and the results from where I sit say it is time to get into the engine totally
If there are any other suggestions we're open for them and none are coming forth. Maybe you might obtain some other possible causes from the other forum, I don't know.
I can understand the cost involved and possibly another engine with less miles and in decent running condition may be an alternative.

Can you have someone with engine experience come to look at the problem ? Maybe they will see something that is escaping your observations and I definitely cannot see from where I sit?

 

 

Did you ever find why you were hearing the unusual glug glug sound from the oil pan or rear of the engine?
Don't underestimate the family mechanic because he is correct , downstream O2 sensor can affect fuel delivery and in some models is used for fuel control.
Instead of looking for possible answers from those of us who do not know everything you did, It might be a good idea to open up the engine again and look for a possible cause reviewing everything that was done right from following the oil passages through the head gaskets and manifold gaskets. There has to be something you overlooked or missed to make it spray oil out that badly.
By the way, welcome to the world of a mobile mechanic service, there will certainly be more like this . BEEN THERE and right now THERE AGAIN !

 

It's still making the sound, but it's getting quieter as the oil level drops. I know for a fact the oil is not overfilled. I've checked many times. I think it sounds like the crankshaft appendages (sorry the name is escaping me right now...I'm talking about the part that extends out from the crankshaft that connects to the rods), are slapping against the oil. Could that mean that the oil is barely making it up in to some parts of the engine? I'm not sure how much oil should be in the pan while the engine is running in a wet sump engine, but maybe that's the issue with the glugging. I'd have to think on it, or maybe someone can tell me if a restriction or blockage in the oil ports could cause oil to spray out. Could this increase the crankcase pressure, forcing the oil past the rings on the intake stroke? The combustion forces would not be fighting the oil in this case and the pistons that are firing at the time could further increase the pressure and cause it to worsen. It would make sense that cylinders 3 and 6 are leaking because this engine is tilted way back when properly mounted, so the oil pan is nowhere near level. I watched the valve train go while cranking the engine and oil was just barely dripping out of the tubes probably just enough to coat each lobe. It looked pretty dry in there. I'm also thinking the glugging sound could be the oil pump struggling to fight a restriction or blockage. My guess in this case would be about a 75% restriction. I realize I switched from questions to statements, but I'm not trying to act like I know anything for sure. So I'll remove the heads and see what I can find. I suppose everyone here's gonna tell me not to reuse the head gaskets. I was thinking about using that copper spray stuff. I'm more wary of re-using the bolts though, but if they do not appear stretched I may just have to try.

I did know that very few vehicles, especially the vehicles using the final generation of narrow band O2 sensors (I assume), probably only use the downstream sensors to monitor the cats. I was speaking specifically to him about my 2004 Suburban 1500 at the time and he was insisting that I was still having fuel trim issues because I needed to also replace the downstreams. I remedied the issue without ever changing them. He also says that just barely touching an O2 sensor with your bare hands will completely foul it. I've rescued O2 sensors that were covered in oil (kinda like the ones in the Sport Trac right now) using gasoline and then baking the sensor with a torch. Most substances will vaporize at these temps and leave the surface almost new. Anyway, that's a little off-subject and not necessary, but I already typed it so I'm leaving it lol.

Thank you for the welcome and for everybody's help!

 

Nick,
You know what you need to do and look at it this way.
Reusing old parts that are supposed to be replaced is gambling and that is OK if it is your vehicle and you don't mind doing the job over again. Cost is always in the picture and you will find a lot of truth in, We don't have time or $$ to do the job right, but we always find time and $$ to do it over! It is not a good habit to get into, you know better.

Doing this job over will be much easier because everything is much cleaner and you only have to pay for the parts. (Easy for me to say) You are much wiser now and will check you work more carefully and be looking for and seeing things you didn't see before. The more we learn the more we realize we don't know.
There are a lot of folks watching and also wondering what the cause of the problem can be and maybe some of them know ,but at this time we don't
As a mobile tech you will find there will always be one that is not in the books and your learning and experience is what will save you. We're watching---do it !

 

Ok heads will be coming off tomorrow and I'll keep everyone updated, but I'll more than likely ask more questions first and include pics. I'm planning on buying new head gaskets, but the reason I was even considering reusing is because the truck has only idled and not long enough to get over probably 140 degrees. Also, at 210 horsepower and a low compression ratio (not sure exaclty what the ratio is)...maybe 8.5:1 or so sounds right. I'd be much more concerned if I was reusing them on my 295 hp Suburban or a more powerful vehicle. These factors would affect the outcome and increase chances of getting lucky and having no problems? But at only $40 for a pair, it's probably worth just getting new ones. Just curious, say I reused them and blew the gasket...wouldn't that only damage the gasket? Shouldn't affect the timing unless the bolts also break and lift the head off. I probably just answered my own question with that seemingly possible outcome, especially if bolts were reused. Should I attempt to remove that oil restrictor screw? It's corroded in and I stripped it already trying to remove it. Should I just drill it out and use a left hand extractor screw and order a new one? I failed to check the oil passages at all simply because I was already cramming way too much info into my head and I didn't think I had it in me to learn about how oil flows and whatnot. Oh and this is my dad's vehicle, not a customer's. I'm not comfortable working on other people's stuff yet, mostly because I'm too slow because there's too much to learn in during the job and every vehicle model is a new learning experience. I also don't have much for tools yet, a big van to travel in, or a business license. It's in the plans though...that's for sure. In this economy you have to do things on your own or you'll just be stuck at the bottom of the totem pole your whole career. I know many would disagree, but millenials (I call it the DIY Generation) are severely mistreated and underappreciated compared to older people...and now for the angry responses from generation X and Baby Boomers haha. Also, I've had issues in the past drilling out steel bolts from aluminum, where the bit goes off-center into the soft aluminum. Is the restrictor screw made of steel? I will be extremely hesitant to use a drill bit in that case. I'll probably use my new MAP/OXY torch and weld something to the screw and remove it. It has a tiny pinpoint flame, so the heads couldn't possible crack or warp if done quickly. Plus steel and aluminum don't weld together nicely so I don't think it'll get fused to the block. Not sure of the diameter of the screw head though, I'm just assuming it's as wide as an oil passage.