91 2.3 burning oil

[00srad600]

i have a 91 ranger 2.3 changed the head gasket a month ago. it was running fine fine for a month. now im burning oil and i keep finding oil in the upper intake any ideas.

 

[RonD]

PCV valve and Vent hose come to mind.

PCV valve pulls air from valve cover, it should pull in some oil vapor but not alot.
I would pull it out of the valve cover and have a look at it and it's hose, see if they have alot of oil inside, if they do then that's where the oil is going and coming from.
There should be a baffle plate inside the valve cover protecting the PCV valve from splashed oil, if it is missing or damaged then it could be sucking splashed oil instead of air.
Check vent hose as well for oil.

If PCV/hose are clean then the next source would be the valve guide seals.
Did you replace the intake valve guide seals when you did the head gasket, is so then maybe one or two were damaged.
If not then maybe they got damaged when working on the head.
Although this wouldn't put oil in upper intake

 

[00srad600]

The pcv is pushing oil but I fixed that and still getting oil in the intake right by the intake tube

 

[Mark_88]

Could be blow-by then...if you take the hose off the throttle body from the valve cover, do you see a white sort of mist coming out?

If not, you may have a restriction elsewhere...causing pressure in the crankcase to build up and force oil out. I know on the carbed versions the PCV is actually just beside the intake near the distributor...and it goes into the base of the carb...but I thought I saw something similar on the FI system...but can't remember...

Is there a pipe coming up from the block beside the intake (or through the intake holes) that has a hose running to or from it? Would be near the distributor (unless they changed to DIS before 90)...

 

[RonD]

The pcv is pushing oil but I fixed that and still getting oil in the intake right by the intake tube

How did you "fix that"?

PCV stands for positive crankcase ventilation

It is suppose to pull air from the valve cover/crankcase area of the engine to be burned with fuel/air mix.

If it was "pushing oil" that means it was in contact with oil, or alot of oil vapor.

If there are no baffle plates protecting the PCV or Vent hoses in the valve cover then oil from the cam/rockers can splash directly onto the PCV valve/vent tube and be sucked in, which would give you oil in the intake.

If you were using cheap oil it can vaporize at a lower temp so cause too much oil vapor, this vaporization is from blow-by which is normal on all engines, but those hot gases will vaporize cheap oil on the cylinder walls faster than "good" oil.
As rings get older, 250k miles, you can get excessive blow-by which can give you more oil vapor even with "good" oil.

Dry then wet compression test can tell you how much ring wear you have.

When a cylinder fires the rapidly expanding combustion of fuel/air pushes down on the piston and makes the crank turn.
The piston has metal rings sliding against metal cylinder walls, so can not seal in the expanding gases completely, so some of this 1,000+degF gas will go past the rings and into the crankcase, this is Blow-by, and is normal.
The cylinder walls are lubricated by the piston oil passages, some oil will be vaporize by the hot gases, but it will condense on cooler parts of the engine.
Cheaper oil can vaporize more so some of it will make it up to the valve cover area and be sucked in by the PCV or Vent hose

 

[00srad600]

I changed the valve cover but as I checked today its still getting oil into the intake but I pulled the hose and put 50 miles on it still burning oil.


Mark88 there is a hose coming from somewhere on the block and go to the intake

 

[RonD]

There is a coolant hose on the intake as well, don't confuse that with a vent hose

 

[00srad600]

There isn't any white mist when I pull the hose on the valve cover

 

[ShotnVA777]

X199 on the PVC valve. Didn't read but the first post, in sure he was right!

 

[ShotnVA777]

Your valves could be letting oil in too!

 

[00srad600]

Ok so is there anyway of changing the valve guide seals without taking the head back off

 

[Mark_88]

There isn't any white mist when I pull the hose on the valve cover

I forgot to mention that the engine should actually be running when you do that...

Ok so is there anyway of changing the valve guide seals without taking the head back off

There is...but it is a bit more complicated than it seems.

I would suggest a compression/leak down test to see if there is a problem with both the rings and valves or one or the other. If one cylinder is lower than the others by 10 to 15% (difference between all cylinders) then you probably should consider an engine rebuild.

If you don't have the resources for a rebuild then you might consider some additives to help prolong the engine life...I've been driving mine with wonky pistons and seals for about two years...and I don't actually recommend this because...just because it is very expensive in oil and additives...but rebuilding or replacing the engine can be a huge outlay of $$$$ and I know what it's like to not have that available...

 

[RonD]

Ok so is there anyway of changing the valve guide seals without taking the head back off

Yes, there is the compressed air method and the rope method.
The changing of the valve guide seals is the same for either.

Remove valve train assembly/rockers
Remove spark plug from each cylinder(only 1 if dual plugs)

Here is the difference in the two methods
Method 1
Rotate crank so 1 piston is at TDC both valves closed
Put compressed air in that cylinder via Spark Plug hole, this will hold the valves closed while valve spring is removed and new seal installed.

Method 2
Put piston about 1/2 way down cylinder, feed appropriate size rope into spark plug hole, couple of feet will do, rotate crank so piston compresses rope against valves to hold them in place, remove valve springs and replace seals.
Rotate crank backwards and remove rope.


Repeat for next cylinder.

 

[ShotnVA777]

Yes, there is the compressed air method and the rope method.
The changing of the valve guide seals is the same for either.

Remove valve train assembly/rockers
Remove spark plug from each cylinder(only 1 if dual plugs)

Here is the difference in the two methods
Method 1
Rotate crank so 1 piston is at TDC both valves closed
Put compressed air in that cylinder via Spark Plug hole, this will hold the valves closed while valve spring is removed and new seal installed.

Method 2
Put piston about 1/2 way down cylinder, feed appropriate size rope into spark plug hole, couple of feet will do, rotate crank so piston compresses rope against valves to hold them in place, remove valve springs and replace seals.
Rotate crank backwards and remove rope.


Repeat for next cylinder.

x2 though, I can't lie, I've never wanted to try the compressed air method. Even WITH all the right tools...

... Only due to me NOT KNOWING how much pressure it needs and scaring the living crap out of myself by semi compressing my entire cylinder head!

 

[RonD]

x2 though, I can't lie, I've never wanted to try the compressed air method. Even WITH all the right tools...

... Only due to me NOT KNOWING how much pressure it needs and scaring the living crap out of myself by semi compressing my entire cylinder head!

Have to say I agree, only ever used the rope method myself, just don't trust "air" to hold the valve closed, it works because I have friends that only use that method but they usually are working on interference engines so valves can't really "fall in" with piston at TDC if air seal is lost.
On non-interference engines the valve stem "should be" still showing if air seal is lost and piston is at TDC but never did the math on that
So I use rope