2.5 4 banger...Ring "Blow-by" or WHAT (???)

[D. Reid]

I have a 1993 Plymouth Sundance with a 2.5 4cyl. 200,000 miles.

It blew a head gasket recently and I replaced it. Hmmmm...I checked the head
deck for warpage and it appeared to be good so I reassembled with new timing
belt and water pump.
I flushed cooling and engine oil systems and reinstalled a quality oil,
filter and coolant.

Everything is fine for a few days then the wife tells me her oil light is
coming on. I check the oil and it is way down with evidence of a major leak
at the Front main crank seal.
So...I pull it down to the timing cover and when a removed the timing belt
cog from the crank I see the main seal blown out of its seat in the timing
cover! Well...I dont know what to think about that. I look at the old seal
and it looks pretty rough. Dryed and cracked around the internal rubber.
With 200K on it...its time for a new one.

Ok...considering the mileage on the car, I go down and buy a new crack main
seal and repair sleeve and install both. They seem to go on ok and the seal
seats into position just like it should.

I reassemble everything and it does fine...for a few days....then The same
old story...oil light came on...2 quarts in 30 miles...oil blown all over
the lower engine and right side of the car...

....THIS time, I put some oil in...start the engine and feel for pressure or
vacuum at the oil filler. Its BLOWING air, BIG time!

Could it be ring blow-by pressurizing the crank case enough to literally
blow the oil seal out of its seat??? Hard to believe, I know...but
possible???

I didnt pull or replace the timing cover, in which the seal seats into last
time. I'm fixing to tear into it again this weekend, but before I do I want
to buy a compression tester and check compression and leak down on the
cylinders.

Anybody have any other ideas, recommendations or suggestions on what might
be going on and the best way to fix it.?
Yeah...the car is high miles...but other than this, and the head gasket, it
has been running fine.

Could the blown head gasket to start with be a clue that I'm not catching???

Thanks in advance for any info you may care to share,

Dave...in (Sunny, Hot, sticky and humid) Florida

 

[Daniel J. Stern]

I have a 1993 Plymouth Sundance with a 2.5 4cyl. 200,000 miles.

Probably getting to be a tired pony by now.

Everything is fine for a few days then the wife tells me her oil light
is coming on. I check the oil and it is way down with evidence of a
major leak at the Front main crank seal. So...I pull it down to the
timing cover and when a removed the timing belt cog from the crank I see
the main seal blown out of its seat in the timing cover! I reassemble
everything and it does fine...for a few days....then The same old
story...oil light came on...2 quarts in 30 miles...oil blown all over
the lower engine and right side of the car...

Mmm. Excessive crankcase pressure.

...THIS time, I put some oil in...start the engine and feel for pressure
or vacuum at the oil filler. Its BLOWING air, BIG time!

How long since the *COMPLETE* crankcase ventillation system -- not just
the PCV valve -- had a thorough going-through? You have 200k miles, it's
definitely time to go to the larger-bore PCV valve.

Could it be ring blow-by pressurizing the crank case enough to literally
blow the oil seal out of its seat?

Yep, it surely could be.

For your reference, my detailed description of your car's crankcase
ventillation system and the larger-bore PCV valve is here:

http://tinyurl.com/yr2pg

-Stern

 

[Bob Shuman]

Sounds like ring blow by to me. I once had a Chevy Vega (2.3L aluminum
block) that blew enough oil in 30 miles (my 1-way commute) driving to fill
up a 1 quart container. I actually designed/implemented a simple "recovery
tank" that had a rubber hose from the oil dipstick to the open air tank.
After about this distance of driving, I used to re-claim the oil by pouring
it back into the oil fill hole and then putting the empty reservoir back in
place.

I did this and supplemented with fresh oil as needed till I could afford a
remanufactured short block with steel sleeves! (I was in college and this
was my daily driver at that time.)

Bob

 

[Kirk Matheson]

Probably getting to be a tired pony by now.


Mmm. Excessive crankcase pressure.


How long since the *COMPLETE* crankcase ventillation system -- not just
the PCV valve -- had a thorough going-through? You have 200k miles, it's
definitely time to go to the larger-bore PCV valve.


Yep, it surely could be.

For your reference, my detailed description of your car's crankcase
ventillation system and the larger-bore PCV valve is here:

http://tinyurl.com/yr2pg

-Stern

Dan, I would like to put the larger bore PVC in my 2.5L Spirit. If I
buy the NAPA PVC for a 3.3L V6, would that do, or should I stay with
the OEM P/N that you mention?

Also, is there an aftermarket source for the "elbow" tube that
connects the PVC to the valve cover housing? Mine is cracked now needs
replacement.

Thanks,

Kirk Matheson

 

[Daniel J. Stern]

Dan, I would like to put the larger bore PVC in my 2.5L Spirit. If I buy
the NAPA PVC for a 3.3L V6, would that do, or should I stay with the OEM
P/N that you mention?

NAPA's OK as long as you get the first-line Echlin, not the "Mileage Plus"
crapola from China. The one you need is a 2-9207.

Also, is there an aftermarket source for the "elbow" tube that connects
the PVC to the valve cover housing?

No. Both the elbow pipe at the center-rear of the camshaft cover and the
formed "almost straight but not quite" one that connects the right-rear
corner of the cam cover to the front face of the air cleaner housing are
dealer-only items. You could probably kludge something up, but don't.

-Stern

 

[D. Reid]

I replaced those parts (PCV valve and rubber 90). The valve was not the big
bore type however. The rubber 90's and some other tubing, I aquired at a
"U-Pull" it yard in this area. You might have to look under a few hoods
before you find a servicable replacement...but it should be cheap...and if
you're buying other parts they will usually give you stuff like this.

I'm going back into this engine this weekend to replace front main seal.
I'am going to see if there is a way to rig a "keeper" device of somesort to
keep the seal in place. Then figure away to release or reduce crankcase
pressure.

Thanks for everyones input.
Dave