I took the suggestion to reroute my pcv hose from the back of the intake plenum to the vacuum tee in the middle of the plenum. Hooked it up with a "t" fitting to the brake booster hose. I found that in cold weather the wet emissions from the crankcase were seeping into the other steel vacuum connections and freezing, effectively blocking flow and producing error codes. My most common one was the code for the MAP sensor indicating a bad vacuum line. The hose was good but there is a low spot in the vacuum tee for that line and it was blocked solid on cold days. I got in there with a coat hangar to push the stuff out several times. So I rerouted the hose back to it's original location and have had no problems with the MAP sensor since. Also I am getting a 1/2" more vacuum at idle?! Ford's original intention may have been to have only the back
cylinders affected by crankcase gunk rather that coat all of them. My next job will be to thoroughly clean the intakes. Cheers.

 

that's important to know! Rerouting the PCV was next on my list...

 

I re routed my PCV hose on my '93 5.0 5spd a year ago and have had no problems at all but in my defence I have an standard trans and had a spare port on the vacuum tree. T-ing into the brake booster was a suggestion I offered in lieu of having the spare tee but I didn't see any problems with this modification but apparantly there are. Good thing you caught it in time,but I have heard that running the PCV into the stock port can cause the #8 cylinder to fail from a hole in the piston. Remember I have only "heard" this and have not experienced it although my truck was running crappy until I did this mod, It wouldn't run on all 8 when going up hills and this simple mod made all the difference in the world. I wished I had know about this before I has spent a pile of money on ignition parts that did diddly to resolve the problem although it was probably time for new parts anyeway. Now all I have to do is fix this nasty Mazda tranny.....
Sorry if I lead you down the wrong path. SR.

 

No problem. Your theory would work except for the low spots in the vacuum tee. An alternative would be to use another vacuum opening separate from the original tee to tie the pcv hose into so wet oil mist and condensation isn't clogging things up. I'm still looking. Maybe I'll just drill and tap another hold into the intake somewhere convenient and make sure it is away from the other things. Cheers.

 

Or, you could add a pcv collection jar to your rig like I did a few months ago. Saw it on a website and it was only about $20 to build, so I did it. Now all the gunk that the pcv system is supposed to catch and recirculate in the engine collects in a jar which I empty about every 2 months. Its some nasty looking stuff, too, I can tell you.
The jar is a catch basin with two fittings in the lid. One fitting connects to the pcv hose coming off the pcv valve on the back of my 300 I-6. The other hose ports from the 2nd jar fitting to where the pcv hose would normally go...in my case, to a fitting about half way down the length of the block on the left side, under the intake plenum. This is really easy to build/install and keeps a lot of gunk out of your engine. My truck hasn't missed a lick since I did this. The only inconvenience is remembering to dump the crud out of the jar periodically. I'll try to find the website link this weekend, and will post it if there is any interest.

 

Did a quick search and found these three links that describe the jar and how to build it:

http://www.totse.com/en/fringe/fringe_science/pcv.html

http://www.fortunecity.com/greenfield/bp/16/ventil.htm

http://www.himacresearch.com/books/hydro8.html

 

That sounds pretty good, I'm going to try it. The 25% increase in fuel mileage sounds alittle fishy, what did you notice in mileage increase if any? Just the fact that all that gunk isn't going into the engine is worth the $12 and time to do! Thanks!

 

Sounds good enough to try. Makes sense. I notice the website that gave the information sells their own brand for about $95 bucks. I actually put together the parts list today and it costs about $15 if you scrounge.
Thanks for the info.

 

Well, I certainly didn't see a 25% improvement in MPG, but I still think its worth it. Just to know that crap ain't going back into the engine. I think the better MPG claim was made back when everything was carburated. I got about 15 MPG before this, and now I get 16-17.5 average MPG. But I went to side-gapped plugs about the same time so I don't know which contributed most to better mileage. I would probably get better MPG if I fed the beast premium octane all the time. Most of my driving is to work and back, or taking the boat to the nearest lake, so I don't pay for the better gas. Oh yeah, forgot to mention. My truck is an I-6 and I mounted the jar behind the battery after moving the vacuum cannister down a ways. That's one of the tricks to this, finding a convenient space to mount the holder under your hood. You want to be able to get to it without having to stretch over hot or moving components.

 

Thanks alot for the info. I appreceiate you taking the time to give us your "real world" experiance.