1988 e150 with 302, 106k
This van had sat for many years. When i bought the van it had just been resurrected. The PO had to put in a new fuel tank, sending unit, and pump. Both valve covers were leaking and he only replaced the left, perhaps because he didn't want to remove the upper intake. I snugged the right side down and it doesn't seem to be leaking, or at least nothing is dripping on the ground at this point. I am not sure if it is seeping around the valve cover because I haven't taken the doghouse off since then, but I don't smell any oil burning.


While I had the doghouse off I noticed oil seeping around the PCV grommet and so i replaced it along with a new PCV valve from the help section at the store, it said for FORD. When I put it in the grommet the engine was idling and I remember it seemed to have allot of suction but I didn't think much about it at that time. i replaced the doghouse and a couple of days later i noticed a whistling sound at idle. Without taking the doghouse back off yet am pretty sure it is the PCV valve sucking air around the grommet.
The fresh air inlet from the right side valve cover has a hose that connects to the air filter box. Not knowing as much about the PCV system at the time, I remember connecting that hose to the breather while the engine was running and there was no vacuum on it when I put my finger over the end of the hose.

I have also had to add 1.5 qts of oil to the engine in a little over 3000 miles. I am not sure what oil is in it right now because it had just been changed before I bought the van. It does have a sticker that says due at 06700. Again the odometer shows 06,200. I don't believe the odometer has turned over twice... I tend to think it would be 106,200. So I am wondering where the oil could be going..

So I got to thinking maybe the PCV is sucking in oil. I have researched a good bit about the PCV system and there is lots out there about it being stopped up but almost no information on air not being sucked in the fresh air vent.. If it is not getting fresh air, it would be pulling a vacuum inside the crankcase? Could that cause the engine to burn excess oil?
It is also getting bad fuel mileage at this point..

As the doghouse is not the easiest to remove, I plan on having it off in a couple of weeks when I replace the AC system. At that time I plan on doing a compression check, check vacuum with gauge,tune up, clean the EGR, ect, and perhaps remove the upper plenum and replace the right side valve cover..

Any suggestions as to why there is no vacuum at the fresh air hose?
Suggestions on where the oil cold be going? Valve seals? But there is no big puff of smoke when first starting the van. i do believe it might be running rich..

Thanks
Anna

 

Hi anna, here's a nearby discussion that may help:
PCV Valve- How it works, how to replace it - Ford F150 Forum - Community of Ford Truck Fans

PCV systems are a replacement for road draft tubes. There endth the history lesson. jim

 

Thanks for the link Jim! I understand the PCV system much better now..
I replaced the grommet and PCV valve at the same time. When it is idling I can hear it whistling. As i give it gas, the whistling goes away. So that indicates the vacuum in the intake manifold is reducing as the throttle plates open, that is what it is supposed to do.. I have read that not all PCV valves are equal. Perhaps Ill try a OEM Motorcraft one.

Right ow I don't remember if I have a vacuum gauge or not, but I do have a mighty-vac and am going to hook it up to the fresh air tube that comes off the right side valve cover and see if there is any vacuum there..
The vacuum on the PCV shouldn't be any higher then say 21.. HG? But when I put the PCV valve in the grommet, it sucked itself in. I didn't think that kind of vacuum was supposed to be created in the valve covers or crankcase.. That is why i was thinking that perhaps the fresh air tube might be clogged somewhere.

I had a friend to follow me and I floored it a couple of times and he said that he saw no smoke. Also thinking that the valve seals could be old...

I have changed the valve seals on a car but not a van. I imagine it will require a different tool for the van as there is less working room. The one I have is somewhat like a pry bar that bolts onto the rocker arm bolt and you pry down on the spring.
looks like this
http://www.ryderfleetproducts.com/im...ols/KDT912.jpg

 

The PCV doesn't really pull a vacuum on the crankcase completely. It is more like a vacuum cleaner operation to remove oil smoke and pull it into the intake to be burned and de-smogged. The valve is weighted to modulate the amount of vacuum applied, don't want to suck the gaskets into the engine, only want to prevent positive pressure in the crankcase.

LOTS of oil in the breather element in the air box points to oil blowby from the piston rings as the engine wears. I have seen breather elements dripping with oil, definitely time for a rebuild or engine swap. jim

 

Thanks Jim..
My breather and air box are dry with no signs of oil. I remember looking at one E150 I saw on craigs list. It was a beautiful van that had been garage kept and well taken care of but I saw a couple of drips on the ground under the front end. We removed the breather ans sure enough it was full of oil!
Coincidentally I had just read a thread on here about that very same subject the day before! I thought $3,500 was a bit high but it was pretty..

I use the van occasionally during the week and almost every weekend but I am going to have to break down and do a compression check and pull the right valve cover just to satisfy my curiosity. My 85 with 140k was 165 give or take a few points across all cylinders. What should the 88 be if it only has 106k? And how is 165? What is normal compression on a new 302? What does 165 indicate?
Hopefully i will get back to working on the 85 by next month.. i had just done the DSII conversion and had test driven it when it quit due to the nasty stuff in the fuel tank.. I have all the new parts but just need to put it back together..

If the compression is good, then I will assume it is the valve seals

 

165 across the board sounds good, the important spec is the difference between cylinders. A few pounds is OK, major difference in readings is not good. The exact same, low reading on adjacent cylinders is bad.

If it is just whistling and no oil anywhere, I would look for an OEM valve. The aftermarket stuff can be very poor quality.