Low Oil Pressure on Revived 318

[Greg Coffin]

I picked up a 1973 D200 today. It has 74,000 miles, and the engine and drive train appear to be in good condition. The truck has a 318 with 2bbl carb, and 435 tranny. It had not been run since 1993.

The truck was parked on a hillside, and once we got air in the tires, we coasted it down the hill to flat-tow it home. On the downhill run my friend put he tranny in third gear and released the clutch to slow his decent. The engine turned easily. Not ideal with dry cylinders, but it was too late to do anything about it at that point. On the way home I engaged the engine a couple times to help lube the engine before starting it up.

Once we got the truck home, I filled the carb with carb cleaner, and pulled the fuel pump and cleaned it as well. Once the fuel pump was primed the engine fired right up. It idled very well, and accelerated with no hesitation.

The oil gauge didn't work at first, so I thumped the dash and got it to free up, but it only read about 20 lbs at roughly 1500-2000 rpm. I noticed that there was a bit of smoke coming from the driver side cylinder bank exhaust, but the engine still sounded good. After about 10 minutes of idling the smoke subsided, but one of the driver side lifters started to make some noise. I also noted that the oil pressure gauge was now reading almost zero. I shut down the engine and checked a few things, but there was no way to know if the gauge was working properly, or if the oil system was working properly.

I have a couple questions about what to do next:
1-Where is the oil pressure sending unit on a 318? I want to hook up a mechanical gauge and verify the oil pressure.
2-If there is no, or very low oil pressure, where should I look next? Oil pump? Clogged pick-up screen?
3-Is there anything to do about the lifter noise?
4-Is there a safe way to remove sludge from the engine other than disassembling it, such as adding diesel or kerosene to the oil and draining it?

Thanks! Greg

[W_A_Watson_II]

1-Where is the oil pressure sending unit on a 318? I want to hook up a mechanical gauge and verify the oil pressure.
A- It's back beside the distributor.

2-If there is no, or very low oil pressure, where should I look next? Oil pump? Clogged pick-up screen?
A- One an engine I always drop the pan, so I'd start there, as I like to do an inspection and clean out the crap in the pan.

3-Is there anything to do about the lifter noise?
A- Other than getting the oil pressure up, and seeing if it continues, none that I know of.

4-Is there a safe way to remove sludge from the engine other than disassembling it, such as adding diesel or kerosene to the oil and draining it?
A- dissassembly and cleaning is always the best, but if you get the oil pressure corrected, I've read where others have used ATF in the oil and run it for a little while in the engine to clean it, but I've never done it and have no opinion or experience in doing it.

Good Luck and keep us posted,
Will

[USN78W150]

oil pressure

Change the oil and oil filter immediately. Put a can of the 5 minute engine flush in there, also. The oil is over 20 years old in that engine.

[DODGEBOYS]

Marvel Mystery Oil

318 lifter tick is common even with good oil pressure

[n1265]

Kerosene works well, but do not hammer on it. Just let it idle. I usually only let it run for 10 min.

It is common for the oil sending unit ( at least on mine ) to show low / no oil pressure when the oil and filter are dirty. A mechanical gauge will tell you the true story. Every time I thought I had a oil problem and I changed the oil and filter, my gauge started to read again...

[DrPepper]

Fiddle with the oil additives , but at the end of the day...

Watson has it right. Drop the pan, pull the pump and clean the pan and strainer. Fresh oil and filter, then you know what it has for oil pressure.
Been there, done that. Talked the dealer down on price when I bought my 1st Townie because the engine had a dead skip and I told him it was a valve job for sure. Pulled the rocker covers screwed down the adjuster that had backed out, cleaned the pan and screen and it ran smooth as silk. He saw me a few weeks later and asked about it, I told him the valve job went great. Really didn't want him to feel bad abouit the deal. LOL
IMHO
DrPepper

[Don Williams]

The above responses are good advice and with only 74,000 miles on the engine I doubt that it is worn out. However, I'll add this info. just for entertainment if nothing else.

My son has a 77 D100, 318, 727 truck that I bought 12 years ago for $150.00. Had to trailer it home but a good tune-up, battery, carb rebuild had it running fine. PO sold it to me cheap after I convinced him I wanted the truck to drive, not resell. My son and I have shared this truck over the years and we each have made many a road trip and she has always brought us back home.

Last fall my son complained that Fred (named for PO) was running rough. I told him to change the plugs and if that didn't fix it I would look at it with him as soon as I got a chance. The new plugs didn't fix it and one day it wouldn't pull the hill as he left work for home. Long story short, a new timing chain was necessary.

After installing the timing chain and getting the truck running I noticed a knock from deep within. Sounded like a rod knock on #7 to me. I asked about the last oil change and he figured it had been a year or so. We changed the oil and filter with an immediate improvement but it didn't last. The oil pressure gauge hasn't worked for a long time so we installed a mechanical one. Gauge showed OK oil pressure when cold but went to ZERO after the engine got warm. So, drop the oil pan and see what's up.

Dropped the pan and found sludge but nothing excessive. Oil pump pickup screen was clean. We installed a new high volume oil pump and put her back together. Results -- oil pressure when cold, 50-60. Oil pressure when warm, ZERO. We know it's pumping oil but by the time it gets to the top of the engine where the gauge fitting is there is not enough pressure to register. Rod knock is still there at times. My advice to my son, "Keep your cell phone charged and don't go on any road trips."

It's entertaining to see just how long a worn out 318 will run.