No Oil Pressure on Start Up, Advice Needed

[4Ewilly]

I am looking for advice on how to troubleshoot my 1952 M38. It was recently rebuilt, and I am trying to get to a start up. When I start it, I am not getting any oil pressure at the oil gauge. Here is what I have done so far:

1. Dropped the oil pan and cleaned and inspected sump screen (it was pretty clean). Shot carb cleaner down the tube to check for blockages. Inspected opening to oil pump, looked clear. Replaced sump and oil sump gaskets. Dipstick looked to be at the right level.
2. Temporarily put in nipple fitting in one of the oil gallery plugs and used a hand pump to prime the system, I was getting oil to the gauge and the oil filter with hand pump. Put the plug back. Also hooked the pump to the end of the inlet hose to the oil filter and pumped oil. Hooked pump to oil filter inlet and pumped oil.
3 Replaced oil pump (thought that was the problem, but it was not). Before installing, submerged the pump in oil and turned gear so there were no more air bubbles coming out.
4. Put in an aftermarket oil pressure gauge on the line to the gauge in the dash thinking the gauge was bad. Took the line apart at the firewall and added the gauge at the end of the line with a length of clear tubing so I could see the oil coming to the gauge. When I start it, I am not seeing any oil in the clear line.

Reading the forums, the only think left that I have not verified is that the machine shop installed the oil jet for the timing gear/chain. I am checking with this community to see it there are other things to check or anyway to verify the oil jet is in place short of pulling the water pump and timing cover (was hoping to avoid if possible).

Thanks in advance for your thoughts and advice.

Randy

[wesk]

We need a wee bit more information.

1 - Which model jeep?

2 - Which model engine?

3 - If L-134 is it chain drive cam or gear drive cam. Danger, gear driven cam rotates opposite direction of chain driven cam. Cam & it’s drive gear must match oil pump driven gear?

4 - Is there any external oil leakage?

5 - Have you confirmed all hidden (inside oil pan & bell housing oil gallery plugs are installed?

6 - Are lifter bore clearances within limits?

7 - If block is later L- 134 gear drive cam or F - 134 is the correct bore gear spray jet installed? (Can only be confirmed by removing timing cover and measure bore.)

8 - Are main & rod bearing Clearances within tolerance?

[Xamon]

Not sure if you missed this one on purpose or not but Oil pump gasket thickness. From previous threads about this I seem to remember that if the gasket is too thick the pump will not work properly.

[wesk]

Good point. I usually do not see a problem with those but it can happen.

[Mikemc]

Is there a pressure relief valve that could be stuck open.

[wesk]

Yes. However I was hoping to initiate a more detailed approach to a thorough troubleshooting effort that starts at a simple beginning and carefully moves forward to more detailed investigative efforts. We can still achieve this goal by resisting any efforts to shot gun troubleshoot. The original poster must still be on holiday and we should allow him the chance to provide the much needed basic background information needed to lay the groundwork for a productive troubleshooting regimen.

[4x4M38]

Wes is right as usual.
We need more info.

I see where you have an M38 but that's all we really know.

For instance, you mentioned you installed an aftermarket
gauge by disconnecting the line at the firewall and splicing in.

The factory M38 is 24 volts and the sender is electric with a wire to
the pressure gauge.

The civvy CJ gauge is mechanical with a flex hose from the block
to the firewall and a hard tube from there to the gauge. This
"sounds" like what you have.

Just an example of why Wes asked for the information he did.
We can't help if we arent sure what you have.

Fill out the questionnaire and the answers will come flying!

Take care,

[4Ewilly]

Wes:

Thanks for your quick reply, sorry I have been slow to respond, we have family in town and lots of activities. Let me also say that I am not an experienced mechanic, but I am learning:)

In terms of your questions, here is my initial reply:

1. The Jeep is a 1952 M38
2. I am pretty certain it is a L-134
3. Not sure if it is chain or gear driven cam. I need to pull the timing cover to tell?
4. I do not observe any external oil leaks
5. Tonight, I need to pull the oil pan to check the gallery plugs. To check the plug inside the bell housing, do I need to pull the bell housing?
6. Uncertain if the lifter bore clearance are within limits. Tonight, I will scan and send the rebuild paper work to give you an idea of what was done to the engine
7. I need to verify the gear spray jet is installed
8. See number 6 above, not sure I know how to check main and rod bearing clearances, need to research that.

Thanks again Wes!

Randy

[4x4M38]

Randy,
The L head has the valve cover on the side of the drivers side of the block.
The F head has it on top of the engine like modern engines.

[wesk]

1. The Jeep is a 1952 M38
2. I am pretty certain it is a L-134. See illustrations
3. Not sure if it is chain or gear driven cam. I need to pull the timing cover to tell? (See Illustrations) Serial number prefixes can give away a chain drive cam. IE MBXXXXX or GPXXXXX or CJ2AXXXXX are all chain drive cams. Engine castings numbers can also help 635718 (Pre-War), 638632 (MA & MB WWII).
4. I do not observe any external oil leaks
5. Tonight, I need to pull the oil pan to check the gallery plugs. To check the plug inside the bell housing, do I need to pull the bell housing? To see the plug yes. But if the plug is loose or missing you will have a very noticeable oil leak inside the bell housing which will drip out the bell housing's drain hole.
6. Uncertain if the lifter bore clearance are within limits. Tonight, I will scan and send the rebuild paper work to give you an idea of what was done to the engine
7. I need to verify the gear spray jet is installed. You only need to remove the timing gear cover not the water pump.
8. See number 6 above, not sure I know how to check main and rod bearing clearances, need to research that. This can only be done mechanically with plasti-gauge.

1946-47 early civilian L134.


Ford built GP, GPW & GPA L-134 blocks


F134 engine. Note top valve cover and height of head.


Chain drive cam gear cover. note pin centered on cam gear,


Gear cam drive cover. Note lack of Pin.


Inner oil gallery plugs


Front oil jet and gallery plug


The 0.040 bore jet is required on all engines now to prevent a reduction in oil pressure to the #1 rod bearing.


All 8 gallery plugs


These clearances can only be checked by dis-assembly and mechanical measurement. A quality engine shop overhaul would have included these measurement and recorded them before & after. They would also have recorded all ring clearances and gaps, all piston to cylinder wall clearances and all lifter body to lifte bore clearance both before & after. If your shop was a quality shop you overhaul report/invoice will include these dimensions.




This explains the difference between Gear & Chain driven cams.

Large size photo is here: http://willysmjeeps.com/v2/modules/gall ... e_Cams.jpg

[4Ewilly]

Wes:

Thanks for your thorough reply. I apologize for not being very responsive, I have two many irons in the fire as usual.

Based on your information, I do have an L-134 and it appears to be a gear drive based on your photos that I match up to my timing cover. I pulled the grill and radiator so I could get a good look and photo of the timing cover. Below is a link to a folder with some photos I took.

I am having a difficult time locating a serial number. There was not a serial plate located where is was in your photo (see my photo of this area). I did locate the following number on the bottom right side (distributor side), also see photos: "641087-L-W10 A N1" I also found the following number on the head: "64016" (see photo). Is there somewhere else I should look?

Still need to drop the oil pan tonight to check oil galleries 7 and 8. Still need to pull Crank Pulley and timing cover to validate oil jet. Any articles or advise on pulling the crank pulley.

I have a called into the machine shop to ask for a detailed data sheet with their specifications, still waiting for a reply.

Photos can be found at the following link (please let me know if you have trouble accessing these photos):

https://photos.google.com/share/AF1QipP ... 5iR1hxdUlB

[4x4M38]

Ok,
A couple of observations.

The line to your gauge appears to be clear vinyl. Correct?
If so, it's way too big. 1/8" copper tubing or equivalent hose
is plenty big. Be sure and check the fitting and line from the block.

The second thing is where does the oil line from the filter go?
The one that leaves the filter, goes up and over the head, through
that grommet in the bracket then down towards the fuel pump?

It should enter the block in a 1/8" tapped hole behind the fuel pump.

One other thing. Move the rubber fuel line from between the radiator hose and fan to behind the hose. The chance of the fan hitting that hose is miniscule
but better to eliminate it completely and not take the chance.

You have a lot of original equipment there. Lots to work with.
Congrats!

[4Ewilly]

I pulled the oil pan to check the internal oil gallery plugs. Here is a photo of what I am seeing:



above where the oil sump arm is connected, I see a threaded hole... Here is a closer photo.



Should there be a gallery plug here??

Randy

[wesk]

Those photo links are not working.

There are only 2 oil gallery plugs inside the oil pan:

[4x4M38]

Your earlier photos have "share" in the links.

The last two have "photo"