Gauge reads 0 Oil pressure and overheating

[6 Nebraska IDIs]

Hey guys,
Writing you from the good ol state of Kansas right now.
Got some bad news and need some input.
I have talked to Mel about it and at this point I've been taking his advice.
We were driving along and all of a sudden the temp light was on, the temp gauge was all the way over past the H and the oil pressure was flat out pegged on L (as in 0).
We pulled over, but noticed the engine was running very well to have NO oil pressure, so we just coasted by the side, and very quickly the temp went back to the middle of Normal, and all of a sudden the oil pressure flickered and came back to Normal as well.
Well the whole way down here we were plagued by the temp gauge rising to the H and when we'd pull over to a stop and put clutch in and the engine would idle down the oil pressure would drop to 0.
If we'd just barely blip the throttle up even 50rpm the oil pressure would pump up and all the way to the A on Normal.
The temp problem we've decided may be real and we're adding more water tomorrow morning. But I'd think if the engine was actually running 0 oil pressure it would have shelled out by now.

 

[Darrin Tosh]

Water pump failure..?

Anyway to see if the coolant is flowing while it is warm and running?

 

[h2odrx]

Sounds like a ground in the dash?

 

[LCAM-01XA]

Wouldn't a ground to dash (or any similar electrical issue) cause the gauge to read zero of full blast all the time tho? As in, it won't change based on rpms, whereas his obviously does... I'm thinking a faulty sender on the engine?

 

[towcat]

time for a set of mechanical gauges.

 

[Diesel JD]

You said it. Lot of needless worry of these factory oil pressure gauges, they tell you nothing when running right and are failure prone to boot. Did you ever get a check engine light? I'm sure that motor would be trash by now if you really had 0 oil pressure. Just get a cheap set of gauges from wal mart or advance and quit having to guess what's going on. I know they're pretty redneck but this is stressful. How are the other issues you wrote us about after getting a good hard run on the highway??

 

[BigRigTech]

Sounds like a poor ground to something else that could be using the gauges for a path to ground....Find a cheapo oil pressure gauge, slap it on and get the actual pressure before you panic...Maybe a 1/2hr of work could save you bigger grief.

 

[6 Nebraska IDIs]

Yea, we've thought about getting a cheap pair of gauges for it, but we're at the 4 Corners, not kidding, and there aint crap here. I could go dig a hole in the middle of the road and ask for one I guess. lol
The radiator was about a gallon low, but the over flow bottle is about a gallon full, lol. I dont know what its deal is.

 

[Mr_Roboto]

Your oil sending unit is an on/off switch. Below 6 - 8 psi it is off and the gauge reads zero, above 6 - 8 psi it is on and the gauge reads somewhere in mid-range.

The gauge "shoots" up because when you raise the RPM up a little is gets that extra 1 or 2 psi to close the switch again.

Hot oil is thinner, which means less oil pressure. Fix your overheating and the oil pressure will be "fixed".

 

[6 Nebraska IDIs]

One gallon low doesnt sound like enough to make it over heat like that, especially when most of that gallon appears to be in the bottle. Makes me a little nervous about this trip back today.
Hopefully we make the hard part before it gets over 100*, because I know that was probably part of the problem, it was supposedly between 105 and 108* coming down here yesterday.
So far we've had zip issues with the oil pressure, and temp seems to be running normal so far, but I AM almost wondering if we've got a bad water pump. Its brand new, but I wouldnt put it past my mind to be bad right out of the box.

 

[6 Nebraska IDIs]

Plus I forgot to mention we're running a can of sea foam in the oil to help clean all the crap out of this engine. Im sure that stuff will thin the oil down considerably.

 

[6 Nebraska IDIs]

The weirdest part was when we first noticed it and pulled over and coasted with the thing idling. It cooled down to normal within 500ft of coasting at idle at the side of the road. Where I'd think coasting at the side at idle should just make it over heat more.
And even when we visually inspected the engine it did not appear to be overheating. Did not show the normal signs of overheating, steaming radiator, steaming engine, etc.
Its all very strange to me.

 

[sle2115]

Plus I forgot to mention we're running a can of sea foam in the oil to help clean all the crap out of this engine. Im sure that stuff will thin the oil down considerably.

Or break stuff loose and clog the oil filter pickup. It did exactly that to a 3.0 that I worked on. The motor had sat for a year or two, I put it in a car to sell, drove it home from parents and oil pressure went to zero a short distance from home. I got it home, pulled the oil pan , and sure enough the pickup was plugged with oil crud. I assumed the sitting let the "crud" solidify, then the sea foam broke it loose. The engine was low mileage and I had the intake, valve covers and oil pan off, everything looked very clean, but there was enough stuff somewhere to plug the screen. I've been leery of using anything like that ever since.

And as was said, you got to get some gauges on there. The factory ones are a joke at best! I have both my in dash hooked up and the digitals. It's amazing to watch the dash gauges move around while the digitals are stable!

 

[icanfixall]

The temp issues seem to be a bad sender. The "check engine" lite is an on or off switch that will peg the dash gage when it closes. You will find it on the drivers side head at the front. Its the large sender and not the samaal sender in the top of the block. Usually it goes bad and you see the dash gage pegged. Pull the wire off the sender in the head and try it again. I'll bet things will be fine. You still have the crappy dash gage for a referance but get a real gage later on. The factory stuff is really just guessing and causing everyone nothing but problems.

 

[Mr_Roboto]

As SLE said, using any sort of solvent in the crankcase is asking for trouble.

Sludge comes loose in chunks, and will block any hole it's too big to go through. Drain back holes, oil pickup screen etc etc.