No oil pressure

This is the place to get help with technical matters concerning your M151 jeep

Moderators: rickf, raymond, Mr. Recovery

Hambone
Brigadier General
Brigadier General
Posts: 2495
Joined: October 1st, 2010, 12:19 am
Location: El Dorado, Arkansas

No oil pressure

Unread post by Hambone » January 12th, 2019, 5:28 pm

Decided to crank one of my old jeeps that hasn't run in about 3 years, cleaned the carb and she fired right up, noticed I didn't have any oil pressure, pulled the sender unit and screwed in a manual gauge, still "0" oil pressure. Drained the oil to see what come out, oil looked fine, no clogs and fairly clean, so my question, can a stuck pressure relief valve cause no oil pressure? I know the pump didn't go bad from sitting.

User avatar
rickf
General
General
Posts: 19741
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: No oil pressure

Unread post by rickf » January 12th, 2019, 5:41 pm

Yes it can and also a broken pressure relief valve spring will do that. You will get circulation to a point but no pressure to push it through the system. Take the oil filter off and start it up and see if anything comes out. Could have dropped the pickup.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

User avatar
rickf
General
General
Posts: 19741
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: No oil pressure

Unread post by rickf » January 12th, 2019, 5:43 pm

Just realized you said it had not run in three years, I would NOT keep running it in this case since there is no residual oil left on the cylinders or top end and little to none on the bearings.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Hambone
Brigadier General
Brigadier General
Posts: 2495
Joined: October 1st, 2010, 12:19 am
Location: El Dorado, Arkansas

Re: No oil pressure

Unread post by Hambone » January 12th, 2019, 6:02 pm

I ran it less than a minute, no oil getting to the filter, pulled the valve cover, no oil, can I access the plunger without pulling the pump or distributor, got to be a stuck plunger, at least I hope it is. Looks like I will be pulling the power pack tomorrow. :(

Mark
Brigadier General
Brigadier General
Posts: 2085
Joined: September 19th, 2009, 11:33 pm
Location: South Dakota

Re: No oil pressure

Unread post by Mark » January 12th, 2019, 6:17 pm

A long time ago, I was driving the 151 and I lost oil pressure ,I was 6 miles from home, I just kept driving it home.Pulled the engine, checked the bearings, oil pump, etc.Nothing wrong, Looked at the oil screen/tube.It was plugged up with dirt, etc.Cleaned it, I put everything together, had oil pressure.I lucked out big time!!
Last edited by Mark on January 13th, 2019, 12:53 am, edited 2 times in total.
mark


1968 m274A5
1960 m151
1981 m151A2
1964 m416
1971 m416

Hambone
Brigadier General
Brigadier General
Posts: 2495
Joined: October 1st, 2010, 12:19 am
Location: El Dorado, Arkansas

Re: No oil pressure

Unread post by Hambone » January 12th, 2019, 6:30 pm

Mark wrote:A long time ago, I was driving the 151 and I lost oil pressure ,I was 6 miles from home, I just kept driving it home.Pulled the engine, checked the bearings, oil pump, etc.Nothing wrong, Looked at the oil screen screen/tube.It was plugged up with dirt, etc.Cleaned it, I put everything together, had oil pressure.I lucked out big time!!
You were lucky Mark, the valve train is very clean, so I'm hoping the bottom end is the same, that's why I'm leaning to the plunger

User avatar
rickf
General
General
Posts: 19741
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: No oil pressure

Unread post by rickf » January 12th, 2019, 7:08 pm

The plunger and valve are in the oil pump. Engine has to come out or front end has to come out but either way the pan has to come off to get to the pump.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

User avatar
rickf
General
General
Posts: 19741
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: No oil pressure

Unread post by rickf » January 12th, 2019, 7:10 pm

I also have one that lost oil pressure while driving, no idea how long before I noticed but 20 miles home and it was still running perfect and quiet. I never pulled it apart to find the problem but I suspect the relief valve spring broke.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Hambone
Brigadier General
Brigadier General
Posts: 2495
Joined: October 1st, 2010, 12:19 am
Location: El Dorado, Arkansas

Re: No oil pressure

Unread post by Hambone » January 12th, 2019, 8:24 pm

Going to attempt to do this while hanging on my motor crane, do I need to go ahead and get #1 on TDC? or can I do it without getting everything out of time?

User avatar
Mr. Recovery
Brigadier General
Brigadier General
Posts: 2892
Joined: December 5th, 2007, 9:03 pm
Location: New Port Richey, Fl.
Contact:

Re: No oil pressure

Unread post by Mr. Recovery » January 12th, 2019, 10:10 pm

Ham, Look at page 3 of my Motor rebuild post http://www.g838.org/viewtopic.php?f=3&t ... p&start=30 Hope this helps!

Dan. PS, Yes, the drive gear is on the pump!!
1960 M151 Run 1
1963 M151 Willys DoD 10-63 in Baltimore
1989 Alley Cat. "work in Progress"
NRA Life Member
American Legion Post 275 Fl
US Army 6 years 2nd Armored Cavalry Bindlach Germany
Colorado Army Nat. Guard 5 years
Md Air Guard 15 years active duty on C-130's

Hambone
Brigadier General
Brigadier General
Posts: 2495
Joined: October 1st, 2010, 12:19 am
Location: El Dorado, Arkansas

Re: No oil pressure

Unread post by Hambone » January 12th, 2019, 10:43 pm

Thanks Dan, now I know what to look for, hope that's my problem.

User avatar
rickf
General
General
Posts: 19741
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: No oil pressure

Unread post by rickf » January 12th, 2019, 10:54 pm

I was sort of hoping the old fart (older fart than me) would chime in with that thread. It would help to get it up on number one before you start and then you don't have to worry about it. If the distributor is in the right place now then getting it on number one and putting it back exactly the same as it came out makes it easy.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

User avatar
muttguru
Colonel
Colonel
Posts: 1992
Joined: November 26th, 2007, 12:18 pm
Location: Li'l ol' England.....

Re: No oil pressure

Unread post by muttguru » January 13th, 2019, 9:06 am

Hambone.... when you re-install the oil pump, make sure that the distributor is removed. The reason? You need to ensure that with the No.1 cylinder at or very near TDC, the oil pump is installed so that the "V"-notch at the top of the oil-pump drive shaft faces forward and parallel to the engine block. If you don't do this, then you'll find that the distributor rotor points to the wrong direction and often results in the distributor not being fully adjustable.
The oil-pump has a spiral cog which engages with the camshaft gear.....when the pump is inserted, the pump driveshaft will rotate so you must compensate for this rotation by checking "down the hole" to make sure the notch points forward and parallel. See piccy below:-

Ken

Image
Kind regards....
Ken

Always wanted - Details and pictures of M416 Trailer data plates & M151 data plates & body-tags for my research. Thanks!

Contact address - - muttguru@aol.com

Note for 2023..... Ken..."Less Stress - More Exercise!"

Hambone
Brigadier General
Brigadier General
Posts: 2495
Joined: October 1st, 2010, 12:19 am
Location: El Dorado, Arkansas

Re: No oil pressure

Unread post by Hambone » January 13th, 2019, 12:17 pm

Thanks for the advise Ken, I will pull the manual out on reassembly, going to pull the engine today, will let you know what I find out.

Hambone
Brigadier General
Brigadier General
Posts: 2495
Joined: October 1st, 2010, 12:19 am
Location: El Dorado, Arkansas

Re: No oil pressure

Unread post by Hambone » January 13th, 2019, 7:38 pm

Well I can tell you it takes 5 hours to change an oil pump, but it wasn't the oil pump, it had about 1/2" of sludge (more like tar) in the bottom if the oil pan, so thick it wouldn't run out the drain plug. Pulled the pump and it all looked good, cleaned the pick up tube, no telling how long the jeep set up before I bought it, so it would be a good idea to check the pan if you purchase a jeep that has set for a long period of time. Now I'm glad to say it is putting out 47 psi at a cold idle. :D. Still need to hook a few things up and put oil back in tranny. Thanks again for all the info. :wink:
Image

Post Reply