How do you fix all of the below listed problems in less than 2 hours and with No Money?

1). Major Rear Main Seal Oil Leak
2). Low Oil Pressure (0 psi) at Idle
3). A lot of Disappearing Coolant
4). Surging RPM on Hot Restarts

Yes this is a true story, I got this truck a couple of months ago for a very good price, of course one look at it would tell you why. Figured it would have some things to fix and it did. Most of the problems were run of the mill and were easy but after awhile I had to face the truth about the things that were left to fix and the story was getting ugly.
With the first 3 problems left (above) it seemed there were few options on how to get a good repair done. I resigned my self to just go ahead and pull the motor and take care of everything at once and do it right. I tried to convince myself I could make it till spring before I pulled the motor. I just couldn't take it off the road in the middle of snow season anyway. Besides the Oil Pressure problem was just the sending unit or the gauge, Right? The oil leak though messy could wait till spring, the coolant leak; well just had to be careful and keep some water and antifreeze with me, I'll make it. (Along with some duct tape and baling wire).

The low oil pressure problem really had me scared, after all I couldn't run the engine with low or no oil pressure even if it was only when it idled. Feeling a bit overwhelmed I focused on a another small problem and that was the Intake Manifold Gasket. Directly in back of the distributor a two+ inch section seemed to be pushed out. I thought this might have a lot to do with the Surging RPM on Hot Restarts. I pulled the distributor, trimmed the gasket off, cleaned up the area and shot a nice bead of Copper RTV in the gap.

As hard as it is to believe ALL of the problems went away, since then I have put over 300 mi on it. The only oil leak is a valve cover that I knew about before. Coolant level is rock steady, surging RPM though not completely gone is 80% better. Oil Pressure is now over Half Scale at all times (sits on the M in "normal").

I think I know why this simple fix worked but I would be interested in hearing other peoples ideas on why. It is a brainteaser especially the Oil Pressure.

 

Dont trust that oil pressure gauge. If its picking up 7 PSI from the sender, it will be somewhere in "normal". If it's picking up less than 7, then it will be down on Low or the red mark. So in reality, you could have 7 or 8 PSI, and your gauge could be clear on the L in Normal, or even clear up in High. Get a real gauge from auto zone or somethin so you can safely moniter your oil pressure.

 

so what happened to the mainseal leak?

 

Rean Main Seal STOPPED LEAKING completly, Question is; WHY?

 

Here are some assumptions that are pretty close to being 100% for the Sending Unit and dash read out.
A Pressure Switch (PS) is activated or deactivated through a rise or fall in oil pressure and provides the "Oil Pressure Indication" for this Engine. Pressure is sensed on the oil supply port directly up stream of the filter as it is routed to the crank bearings and other passages. The PS will CLOSE on an increasing pressure of about 7 PSIG. The CLOSING of this switch allows the circuit to be completed from source to ground. This in turn allows a small current to flow (milliamp) through the Oil Pressure Indicator on the dash. This current causes the gauge to deflect probably through the creation of a magnetic field, which becomes the motive force to move the needle (SWAG theory(Go ahead ask what it is). Or it is using a voltage drop across the dash meter to make the needle swing based on the position of the PS contacts and there associated Ohmic values. Since it’s not broke I really don’t care how it works at this moment, of course that can always change.

The PS OPENS on a decreasing Pressure of about 7 PSIG to cause the gauge to indicate "LOW".

I would also venture a guess that there are 3 positions for the PS,

LOW = OPEN CIRCUIT (< 7 PSIG)

NORMAL= CLOSE TO GROUND through an internal high Ohmic value resistor (7-60 PSIG Guesstimate)

HIGH = CLOSE TO GROUND through an internal low Ohmic value resistor. (>60 PSIG Guesstimate)

 

All I can think of is the PCV isn't working to vacuum the engine gases or there wasn't enough vacuum. The gases built up pressure and forcing oil out of the mainseal.

Anyone else?

 

I was thinking the same thing Tim.

 

Packed enough rtv into the intake to fix vacuum leak or filled 1 and 3 intake ports entirely fixing high idle. Packed rtv into coolant leak in cracked head stopping water from steaming the cylinder with the cracked piston. Water stopped getting into the oil so now the oil is lower than the rear main seal. Monkeyed around enough to jiggle sending unit/ground wires to gauge, or rtv has blocked an oil passage and increased psi. How'd I do?

 

Pretty GOOD, I think you could do a Stand Up "RTV" comedy spot with that material. You are right I believe, with the Low Vac due to the leak could/did cause the oil to blow, the Oil Pressure coming back to normal; I have a theory on it but I would like to hear some other ideas before I post it.

KEEPEM COMIN