ok. so. i'm new here. and came here for a reason. i don't know these new motors all too well. and the vortec v6 is so clustered you can't really see anything. but here's the deal. any suggestions or ideas would be real helpful.

i was getting ready to replace a tie rod and ball joint. the blazer's been sitting for about a week waiting for it. it's a 99 blazer ZR2. i noticed that i developed a fairly significant oil leak. got under it and started looking around. the whole bottom is coated....pan and all....even back to the trans pan. plug's in nice and tight....doesn't look like that's where the leak's coming from. poked around some more....wiped and cleaned things to get a better look....pan gasket seems fine. glance up.....block's got oil on it. start thinking hey....maybe i blew the headgaskets or something. headgaskets look fine. no leak around them anywhere. but there was some oil on the front by the intake manifold. maybe it's coming from there. maybe that gaskets blown. then i check the filter....open up the little door....filter's tight....but covered. all the oil lines are covered. everything under there in that little trap door.....is soaked with oil. but when i fire it up and try to watch for a leak....i still don't see it. i was thinking it might be the lines....but there's no spray....and with how much of the block is covered with oil....it'd have to spray to look that bad. now the whole pulley assembly and everything looks like it's all a separate part from the block.....sounds retarded i know....but i can't think of how to explain it.....it's like there may be a front main seal or something on this motor.....this is one motor i really don't know much about. so i'm kinda stumped on where this leak....this shower...could be coming from. but i did notice one other thing. coolant. my coolant is not pretty. not green. rather quite dark....and brown....like oil may have mixed in. now from my experience with cars....there's only so many ways that can happen....and none of them are good. so....any ideas on just how screwed i am? or where this oil could be coming from?

 

On the coolant....
these trucks come with the orange dex-cool. When air gets into the system, as tends to happen over time without good maintenance, the dex-cool turns horrible rust colored and fills your system with this crap that looks like mud. You might just need to flush it out really well and put green in there. That is what I did when I got my blazer a few months ago.

The crimps on the oil lines to the remote oil filter housing and the radiator are very bad about leaking. If there is oil there, that would be a good place to start. Oil would have a hard time blowing forward! Over a long time with a leak, god only knows how much it could coat things with oil. Mine is doing the same thing, so I am going to replace my lines.

I also found two oil pan bolts missing on mine, causing a leak. You might check your bolts to make sure they are tight, and make sure they are all there.
Mine had oil and grime everywhere making it hard to see what was going on with leaks ....so I took some engine-brite and a water hose and cleaned things up a bit. Now I am working on tracking down all my little leaks.

That would atleast give you a start.

 

Your oil leak is most likely from the valve cover gaskets which are a quick, easy, and best of all inexpensive fix (if you do it yourself). I had a problem with the pan bolts on my Bravada coming loose. All fixed now, but drove me nuts for quite a while.

On the coolant, it sounds like you need a good flush. The OEM coolant is GM Dexcool and despite what the vast majority of people have to say about it, it is a good long life coolant. It does have more problems when air is present in the system than the old green stuff. Dexcool is red to start with. I would recommend that you do a good flush of the system, replacing the t-stat and the radiator cap. I used Prestone yellow coolant which is an extended life coolant like Dexcool, but is good for all makes all models and doesn't have the compatibility problems that Dexcool has. When you do the flush, make sure that you remove the heater core hoses and do a forward and reverse flush of the core to make sure that scale and other buildup hasn't plugged the core up.

Any other questions, just ask!

 

i checked the valve cover gaskets along with the head gaskets...those were the first 2 places i really started looking hard. i mean no offense.....but that's kind of an obvious one. and the leak is definitely not coming from there. it looks to me like if it's a gasket it's the intake manifold. but it looks more like a bottom end problem. i'm leaning more towards the oil lines. seems to be about the most logical option. but being that i have taken it off roading.....it wouldn't surprise me if maybe some bolts are loose or missing....especially since i noticed a small chunk missing from the front bottom of my transfer case.

 

No offense taken, but seeing as how you never mentioned the valve cover gaskets in your original post, and more than a few have been known to leak, it needed mentioning.

On the oil lines, they really don't spray, but rather, drip. That is unless you have nicked them while offroading...

Now another area that is a possibility is a leaking oil pressure sending unit or a leaky distributor base gasket.

 

now there's a couple spots i never thought of. and i was thinking on the idea of the lines being up front....and if they're dripping as i'm driving.....then they'd kinda spray back in a sort of way....to where it could coat the other areas. an di like i said....i may have nicked them while offroading....and you're right....i didn't mention the valve cover gaskets....i guess in my mind the valve cover and head gaskets just kinda go hand in hand.

 

front main seal will coat the bottom of the oil pan if its been leaking

 

that was another one o fmy worries.....when i looked at the front of the block....it looked like that may also be the problem....bu ti guess until i scrub it all down and star t watching it closely.....i'll never know for sure

 

Have you monitored how much oil you are actually losing?

 

That's where I would start, clean it off first and then check it daily. I use brake and parts cleaner for cleaning off oil.
The problem is that a small leak can be blown back by the cooling fan.
Oil cooler lines are a common leak, the front timing cover seal behind the balancer is not as common, but possible.