Oil Pressure problem after valve work |
Post Reply | Page 12> |
Author | |
MooCow
Member Joined: 20 Mar. 2016 Location: Belton, Mo Status: Offline Points: 101 |
Post Options
Thanks(0)
Posted: 07 Aug. 2020 at 2:03am |
Looking for some help. I recently installed new valves, valve guides,pistons, rings and rod bearings while the motor was in the jeep. Had all the right tools, did everything correct and the engine runs great after I was done. Now I am noticing low/no oil pressure at idle when the engine gets warm. A slight bump of the accelerator to get the RPM's up a bit and it goes up to 10-12PSI, crusing down the road at mid RPM I have about 20-25PSI. I did not notice this before the rebuild. I did the rebuild because my valves and guides were a problem. I did the pistons and rings because I had it opened and they were original. The engine has 19,000 original miles and everything was in spec, I went back with standard bearings. There is no noticeable noises coming from the engine. I think my gauge is good as it acts correct while the engine is cool. My next step is to replace the oil pump but wanted to get some others thoughts first.
|
|
1949 CJ3A
|
|
Joe DeYoung
Member Sponsor Member x 2 Joined: 20 July 2005 Location: Madison WI Status: Offline Points: 3362 |
Post Options
Thanks(0)
|
My first thought... don't fix something that is not broken... especially with repro engine parts. Ok... so you did and now you have trouble. Did you check rod bearing clearances after installing the new bearings? Did you remove the cover and clean out the oil pick up float. I would start there.
|
|
Joe DeYoung
to many jeeps, parts, and accessories to list here, but apparently enough to keep me in trouble with my wife. |
|
Bruce W
Member Joined: 29 July 2005 Location: Northeast Colorado Status: Offline Points: 9651 |
Post Options
Thanks(0)
|
Considering what you did, there's nothing there that could affect oil pressure except the rod bearings. They must have too much clearance. Did you check to make sure that the old bearings were not undersize? Maybe the crank was turned sometime in the past. Did you Plastigage the new bearings? Did you measure the rod bearing journals?
"Had all the right tools, did everything correct" I love it when someone says that and then goes on to tell us how something is not working. Obviously, something was done "not correct". Incidentally, you did NOT do a "rebuild". You did an in-frame overhaul, or what the old-timers called a "ring-bearing-and-valve job". Good Luck BW
|
|
It is NOT a Jeep Willys! It is a Willys jeep.
Happy Trails! Good-bye, Good Luck, and May the Good Lord Take a Likin' to You! We Have Miles to Jeep, Before We Sleep. |
|
MooCow
Member Joined: 20 Mar. 2016 Location: Belton, Mo Status: Offline Points: 101 |
Post Options
Thanks(0)
|
OK, let me clear things up. I have rebuilt 4 motors in my life from 1000 hp turbo race engines to the 351C in my 73' mustang. When I say I did everything correct I am talking about the right tolerances, everything clean, assembly lube, etc. I was just trying to point out Im pretty mechanical for reference. I realize something is wrong and understand it is most likely with the bearings but was looking for some alternatives as well. The jeep did sit unused from last April until this March when I got it back together. With that being said I did plastigage the bearings before I took them out and did the mains as well to see the shape of the engine. I know where the jeep was most of its life so I am pretty sure the motor had not had anything turned down. I checked 1 when I put it back together to confirm it was correct but did not check all 4. I did take the oil pickup out and cleaned it but it was pretty clean. One of the pistons had a pretty good knick in it so I bought 1 and they sent me all 4 by mistake so I swapped all 4. This winter I will most likely drop the pan and check things out but thought I would see if there were any other suggestions for the short term to get me through the FCT. I have been driving it for about 500 miles since I did the work, I just don't let it idle much when it is at temp.
|
|
1949 CJ3A
|
|
flatfender47
Member Sponsor Member Joined: 09 Jan. 2006 Location: Riverside CA Status: Offline Points: 646 |
Post Options
Thanks(0)
|
How was the oil pressure before the in frame rebuild ?
|
|
1947 CJ2A 225V6 SM420 D30 PLok/D44 D/Locker Warn OD 5:38s
|
|
Mark W.
Member Sponsor Member Joined: 09 Nov. 2014 Location: Silverton, OR Status: Offline Points: 7984 |
Post Options
Thanks(0)
|
so you do not mention having the rod journals ground to an undersize. So you threw new bearings on the journals in the condition found? Not a good idea.
|
|
Chug A Lug
1948 2A Body Customized 1949 3A W/S 1957 CJ5 Frame Modified Late 50's 134L 9.25"clutch T90A D18 (1.25") D44/30 flanged E-Locker D25 5.38 Since 1962 |
|
MooCow
Member Joined: 20 Mar. 2016 Location: Belton, Mo Status: Offline Points: 101 |
Post Options
Thanks(0)
|
It was low at idle but not as low as it now. Maybe 5-8psi now it is closer to 0-5. Obviously the gauge is not the most accurate scale.
|
|
1949 CJ3A
|
|
Michaeltru
Member Sponsor Member x 3 Joined: 22 Oct. 2012 Location: Arizona Status: Offline Points: 988 |
Post Options
Thanks(0)
|
Maybe try a different gauge?
|
|
Mike in AZ
|
|
MooCow
Member Joined: 20 Mar. 2016 Location: Belton, Mo Status: Offline Points: 101 |
Post Options
Thanks(0)
|
I did not, there was not much wear and thought I could get by as every thing checked out. I have no problem tearing back apart this winter if we think I can make it through the fall the way it is.
|
|
1949 CJ3A
|
|
67charger
Member Joined: 27 Sep. 2011 Location: Kentucky Status: Offline Points: 1272 |
Post Options
Thanks(0)
|
Did you put a new oil pump in when you replaced the bearings? If the engine tolerances are correct, it could be your oil pump going bad. Like others have said too, try another oil pressure gauge.
|
|
Oldpappy
Member Joined: 09 Apr. 2018 Location: Tennessee Status: Offline Points: 4908 |
Post Options
Thanks(0)
|
There is no need to have the crank journals turned if in good shape and within spec on clearance. Don't fix what isn't broke.
If a bearing insert was in backwards it would block the oil passage, but you would see more severe signs of that in a hurry, particularly if a main insert was backwards. So, I doubt this would be the issue.
If indeed clearances are right, I would check the oil pump to see if it is in spec for tolerances, and also check the relief valve which controls pressure. Some people remove shims on the relief valve, or they get missed during reassembly. I always start with the easiest thing first. |
|
If you can't get there in a Jeep you don't need to be there!
|
|
TERRY
Member Sponsor Member Joined: 22 May 2007 Location: BOULDER COLORADO Status: Offline Points: 3400 |
Post Options
Thanks(0)
|
What weight oil is in it?
|
|
BOULDER 48 2A
|
|
Mark W.
Member Sponsor Member Joined: 09 Nov. 2014 Location: Silverton, OR Status: Offline Points: 7984 |
Post Options
Thanks(0)
|
Putting new bearings on old journals can lead to rapid wear.
|
|
Chug A Lug
1948 2A Body Customized 1949 3A W/S 1957 CJ5 Frame Modified Late 50's 134L 9.25"clutch T90A D18 (1.25") D44/30 flanged E-Locker D25 5.38 Since 1962 |
|
jeeper50
Member Sponsor Member Joined: 01 Mar. 2008 Location: Spanish Fort AL Status: Offline Points: 2579 |
Post Options
Thanks(0)
|
My barnfind rering job turned out fine
|
|
Belleview ol skool winch soon. '48 CJ2A 283 V8 sm 420 granny low, tera low D18, overdrive,lockers Texan at heart,Alabama by retirement |
|
Bruce W
Member Joined: 29 July 2005 Location: Northeast Colorado Status: Offline Points: 9651 |
Post Options
Thanks(0)
|
When I first started at the local Chevrolet dealership in 1969, there were a lot of pre-war and early post-war farm trucks still in use in the area. And we did a lot of “ring-bearing-and-valve” jobs. Nobody ever said they were not a good thing. One thing I got to learn was how to align the troughs and nozzles for the “dipper” oiling systems. I still have the tool for that.
We definitely did not refer to these jobs as “rebuilds”. We did that too, but it’s a whole different deal. BW
|
|
It is NOT a Jeep Willys! It is a Willys jeep.
Happy Trails! Good-bye, Good Luck, and May the Good Lord Take a Likin' to You! We Have Miles to Jeep, Before We Sleep. |
|
Mark W.
Member Sponsor Member Joined: 09 Nov. 2014 Location: Silverton, OR Status: Offline Points: 7984 |
Post Options
Thanks(0)
|
I said it "can" lead to problems
|
|
Chug A Lug
1948 2A Body Customized 1949 3A W/S 1957 CJ5 Frame Modified Late 50's 134L 9.25"clutch T90A D18 (1.25") D44/30 flanged E-Locker D25 5.38 Since 1962 |
|
Bruce W
Member Joined: 29 July 2005 Location: Northeast Colorado Status: Offline Points: 9651 |
Post Options
Thanks(0)
|
And you are right. BW
|
|
It is NOT a Jeep Willys! It is a Willys jeep.
Happy Trails! Good-bye, Good Luck, and May the Good Lord Take a Likin' to You! We Have Miles to Jeep, Before We Sleep. |
|
Oldpappy
Member Joined: 09 Apr. 2018 Location: Tennessee Status: Offline Points: 4908 |
Post Options
Thanks(0)
|
To my way of thinking this is one of the differences between an "overhaul" and a "rebuild", especially an "in frame overhaul".
In my opinion if the crank needs to be turned, an in frame overhaul is out of the question and the engine is ready for a rebuild. An overhaul is a much less expensive way to get it back in service quicker, but a number of factors besides the cost need to be evaluated before deciding the engine is a candidate for that. Worn or scored journals would certainly be a big factor here, and slapping in new bearing inserts when the journals are not in great shape is just prolonging the inevitable, and will cost more in the long run. |
|
If you can't get there in a Jeep you don't need to be there!
|
|
Post Reply | Page 12> |
Tweet |
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |