Porkchok

Pulled my VC this morning to make sure I had the correct torque on my distributor cam gear bolt (just did the timing chain job on her) and I found a bit of moisture in there. Nothing too alarming but definitely something to address.

Some pics :

Front driver's side head bolt there :



Under-side of valve cover with some moisture under where the two front grommets seal :



And a bit on the underside of the oil-fill cap :



Some pics of inside the timing cover to see if there was any moisture there:


(Notice more moisture on the inner edge of the front half-moon plug.)


(Thought this was a really cool shot. )



All seems to be well inside the timing cover. I'm hoping to attribute the moisture to an under torqued valve cover since I didn't have the torque specs handy when I reinstalled it the last time. I just put it on tight enough to seat the gasket (or so I thought) and stopped.

I also have noticed that when I open the oil-fill cap after the truck has been running, there is some kind of gas coming out of it. (exhaust? Hopefully not steam! >.<) It seems like I've heard before that is normal and it's probably caused by a part of the emissions system?

Another thing I've begun to notice is that my oil is definitely getting contaminated with gasoline. There's no mistaking that smell under the valve cover and on the end of the dipstick. (Could be unrelated. Have yet to replace my fuel pump and I've read about the diaphragm leaking)

One last thing is that I noticed the lobes on my cam are not worn uniformly. Some are bright and shiny and polished, and others are very dirty and gunked up. Here are pics of what I'm talking about. :

Cylinder #1: Lobe for intake semi-dirty. Exhaust lobe nice and shiny.



Cylinder #2: Intake lobe dirty. Exhaust lobe semi-clean.



Cylinder #3: Intake lobe clean. Exhaust lobe clean.



Cylinder #4: Intake lobe bright and shiny. Exhaust lobe very dirty.



The reason I include this is that I'm wondering if any of these issues could be due to bad valves/valve seals/valve adjustment and if the inconsistent wear on the cam lobes could be evidence of any of those.

I am somewhat of a newb mechanic but doing my best to learn. Thanks a ton, Yotatech!

Cheers,
Pork

vital22re

iTrader: (2)

I edited the first pic for you. You need to use the image code, not the direct link.

Porkchok

Thanks, pal. I'll edit the rest when I get the chance.

Porkchok

Photos embedded. Thanks again.

Co_94_PU

iTrader: (-1)

Nope try again it'sthe second one from the bottom labeled "IMG"

Porkchok

Haha. Whoops. Tried doing it from my phone. Still at work. I'll get it when I get home.

Porkchok

There we go!

Porkchok

So I've replaced the fuel pump with a brand new one. Drained the oil, dumped 3 quarts of o'reilly's 10w30 in and let that drain, then refilled her with Valvoline MaxLife 10w30, and replaced the old Bosch filter with another Bosch. Unfortunately there is still a strong smell of gasoline coming from inside the valve cover. Somewhat luckily, my front seal is leaking pretty badly so I'm topping off the oil pretty consistently. I say luckily because I figure by replacing what's in there with fresh oil, I'm bringing the raitio of oil:fuel back toward the oil side of the spectrum...

Could my problem be in the carb? I've had the truck about 3 months now and have done quite a bit of work to it including the timing chain, but I haven't yet touched the carb. Looking for some more suggestions on things to test in order to get this taken care of.

Cheers

Co_94_PU

iTrader: (-1)

Some highway time will help dry out the hydrocarbon in the oil. It happens more from city driving due to reduced temps and increased engine load from all the stop and go.

Have you done compression and leak-down tests yet to figure out which way it's getting in there? is it rings or valves..

A Carb' rebuild can't hurt, well unless you do it wrong Someone else would have to chime in on if you can lean the fuel mixture out and how much, I don't do carb' work we don't get along I lose springs.

Porkchok

She doesn't get any highway time. Back and forth to work, about 20 miles round-trip, stop and go. It's only got the 4 speed anyways.

I haven't done any leak-down or compression testing yet. I guess that would've been step one.

A carb rebuild is on my list but the oil leak and gas in my crankcase take priority. Unless of course that is where the gas is coming from but if my understanding is correct that isn't really possible without bad rings. Plus I don't have cold start issues which would be associated with the carb leaking and flooding the combustion chambers.

I will try and make it this weekend to get a loaner leak down tester from auto zone or the like. Is there any advantage to running both the leak-down and compression tests? I am under the impression that the comp test is just a crude leak-down test.

Co_94_PU

iTrader: (-1)

Weekend road trip season it's here! Sorry my googlefoo is failing me today I can't find the tech info I wanted to link for you. Thought it was on autoshop101.com but I'm not finding it. Essentially it explained how the low speed and stop and go city driving increases fuel blow by. There are two reasons that I remember one is the operating temperature when driving below ~45 mph doesn't get high enough to re vaporize the fuel out of the oil, the other has to do with the pressure difference in stop&go traffic which I can't recall properly to explain (sorry).

How is your fuel economy? If this is dropping it hints at poor atomizing which will cause excess fuel blow-by and ring un-seating which is self reinforcing to the problem. eg the more liquid fuel that gets to the rings causes them to leak more. A carb' rebuild/cleaning will help with this.

A compression test is different from a leak down test, they tell you different things. The compression test tells you if you're getting proper compression to yield proper combustion. There will always be some leaking, most commonly it's the gap in the rings which is why the alignment (actually offset) of the gaps is critical. A leak down test tells you how bad the leak is and allows you to figure out what part is leaking (intake, exhaust, or rings)

Now Wikipedia does say the compression test is "a crude leak down test" but I'd say take that with a grain of salt. To a certain extend it doesn't matter how bad it leaks as long as it produces enough pressure. The reason being it only has to contain it for a minute amount of time. So in my mind the compression number is more important to know if it's getting full combustion. Of course it's a slippery slope between full combustion and lost power, but most of us aren't building race motors. Look at it this way which is worse only burning 80% of the fuel or loosing 20% of the power produced from what ever fuel you are burning. Too lazy to look up the math today but I'd bet you better off burning more of the fuel, since you're always going to loose some of that to leakage you want the best combustion ratio you can get, this is why race cars aim for higher combustion ratios.

Sorry I might of got rambllng there. get you some steady over 45mph and you'll get less diluted oil. Good clean carb' jets can't hurt either.

Also if you're still listening and happen to be running anything with an EVAP system like a EFI, they don't purge below 45mph. And MTBE additives make the computer feed more fuel due to a "false" oxygen reading.