318 magnum question...

[dutch]

ok,  my friend`s van developed a new problem   
96 dodge ,170K miles, 15w40 oil
-after driving a bunch of highway miles his oil pressure dropped to the red light at idle. Revving it up made pressure climb again, but not shooting up. My  initial thought was rod bearings toast , but can this happen from one day to another?  Could it be a clogged pick up?  or filter?  (ac delco.... been in there for 20k miles     )
-Then he calls me a few hrs later... he removed the rad cap with a cold engine and gets a splash of coolant...     I went over there and drove the van for a while. No pressure build up in the cooling system, no smelly exhaust fumes   
-One more strange thing with this engine:  it`s been losing oil for some time now.  No burning and no leaks ( just a tad sweaty) that one would expect with 1 pnt / 1k mls . 

so, am I missing something here? I hate pulling engines from vans 

[MEK-Dangerfield]

I am NO authority here, but I'll chime in. 

Was the engine low on oil enough to cause the first problem? 20K miles on the oil filter is also not real nice to the engine.

The losing oil thing could be bad valve seals. I had a Pontiac with the same mileage, and you would just see the bluer smoke on start-up.

[dutch]

thanks Mike,
nope... enough oil on it.  I hear you on the filter    I wonder if a dirty filter could cause pressure to drop like that.....
There is no blue smoke or oil smell what so ever.... that`s what dazzles me  nor any puddle underneath.

[mrwfp]

I had the same problem with a 95 van that my son has at school about 6 weeks ago.  It lost 3 quarts in 2 days.  My son took it to Manny, Moe and Jack who said for $1800 they could fix the leak in the valve covers, oil pan and front seal.  I knew those leaked a little but not 3 quarts in 2 days so I told him to top off the oil and drive it the 50 miles home.  He drove it home and we discovered that the oil pressure sending unit had a crack that was spritzing out oil as he drove down the road, but not at idle.  A $35 part that took about 10 minutes to replace.  No more big oil leaks.  Check that oil pressure sending unit.

[moparman82]

I had the same prob with a 96 ram 5.2, replaced sending unit,, problem solved

[Super Blue 72]

How long has he been driving on the oil in the engine?  What does it look like? Clear?  Brown?  Any fuel oder?

I agree with mike, 20k on the same fileter is a bad thing.

Change out the oile and filter and see what happens.  That would be my first step.  It sound slike the oil level is ok so I think it's a viscosity thing or a bloackage somewhere.  Hopefully the pump isn;t bad.  Do the easy stuff first.  Change the oil.

Not saying it's the same issue but I had an oil pressure drop like real quick and it was fuel in the oil from a leaking carb.  Not saying your friend has this issue (My oil level was a quart over max) but it's probably some flukey thing.

[dutch]

thanks for the replies guys.  Oil will be changed tomorrow, and I think he knows now he is supposed to change a filter every so many miles and not every so many years...LOL.
I will look into the OP sending unit 

[RCCDrew]

Losing oil in a magnum usually means plenum gasket.

X2 on the sending unit being the problem with the oil pressure.

[Super Blue 72]

Losing oil in a magnum usually means plenum gasket.

X2 on the sending unit being the problem with the oil pressure.

What's a plenum gasket? 

[spamtank]

What's a plenum gasket? 

Maybe intake plenum (manifold)....   

[Super Blue 72]

Aha!  Gotcha, thanks! 

[RCCDrew]

Sorry, yeah the intake plenum. The gasket will leak sucking oil into the intake.
You can test by plugging the pcv valve and the oil breather at the valve covers with your thumbs. Pressure = good gasket. Vacuum = bad.
There are plenum upgrades for the magnum motors also.

[dutch]

I ll test that, thanks.
looks like the oil pressure thing was the oil filter.