Low Oil Pressure

mrichards

New member

Equipment
B6000
Sep 28, 2010
9
0
0
W. Lafayette, IN
I have a B6000 and I noticed that the oil switch light would remain off right after start up, but once the engine was warm it would come on and remain on even at high engine rpm. Owners manual says the switch closes at 7psi. I removed the switch and installed a 15psi pressure gage. When the engine is cold and at idle, oil pressure is about 5psi. Hi speed is between 7-8psi. After warm up the oil pressure is about 1-2psi at idle and 3.5-4psi at high speed. Owners manual says to check bearing clearance for low oil pressure. Not sure I'm ready to tear into the engine to replace all of the bushings in the oil path. Is this typical increased clearances do to bushing wear, or a problem with pump? If I continue to operate at this condition will I damage something? Thanks for you help.
 

ipz2222

Active member

Equipment
L235, bx2670
May 30, 2009
1,927
31
38
chickamauga ga usa
Operating at that low a pressure will damage the eng. Before you start tearing it apart, search for (low oil pressure), in the search forum. You will find several threads with several ideas, some with quick fixes.
 

mrichards

New member

Equipment
B6000
Sep 28, 2010
9
0
0
W. Lafayette, IN
Thanks for the info. Did some search on Google, apparently a common issue with this engine is that the oil path goes through a center hole in the cam-shaft and the ends of the cam-shaft are plugged with an aluminum press-fit plug. These tend to come out and create a leak in oil circuit that causes pressure loss. I removed the front end and the oil pan........plug in the bottom of the pan. I removed the gear case cover and yep, missing the plug in the cam-shaft. This is a design flaw I think because aluminum thermal expansion coefficient is much higher than cast iron and over time with thermal cycles it appears the aluminum takes a set that reduces the press fit. Fortunately, the one that came out is on the front. I am reluctant to put another aluminum plug in there, even using retaining compound (loctite 680/634). Spoke with dealer mechanic and some other motor-head types and I've decided to tap the existing hole (7mm) with a M8x1.25 to a short depth, 8mm. Then drive an M8 set screw into the hole with loctite 263 (high strength, high oil resistance, high temp. Let me know what you think about this. Of course I am worried about metal in there. I will definatley take care to insure that bring the tap out every 1/4 turn to pull the shavings out, as well as use a magnet to clean is out one final time. Let me know what you think.
 

ipz2222

Active member

Equipment
L235, bx2670
May 30, 2009
1,927
31
38
chickamauga ga usa
MAN, am I glad you found that. It has been discussed here several times and no one knew aabout that. You can problably find a steel plug to press in there but the drill and tap sounds better. Unless that cam is too hard to tap. Can you post a picture of that missing plug????
 

mrichards

New member

Equipment
B6000
Sep 28, 2010
9
0
0
W. Lafayette, IN
Yep, I'll take some photos and post them tonight. I am still debating on tapping that cam. I would prefer not to do that. I ordered a new plug so that I can take some measurements. Maybe machining an iron plug would be better. I am curious if the new plug will be made of aluminum, knowing that this is a common issue. Will keep you posted. I'm happy I found it too. I'm also debating on inspecting the rod and crank bearings for wear. I don't know what they are supposed to look like. Will keep you posted.
 

mrichards

New member

Equipment
B6000
Sep 28, 2010
9
0
0
W. Lafayette, IN
Checked the lower rod bearing, nearest the clutch. Looks great! Couple of light score marks nothing deep. Not bad for 33 years and a lot of hours. Will post pics soon.
 

mrichards

New member

Equipment
B6000
Sep 28, 2010
9
0
0
W. Lafayette, IN
Sorry for the late response. First image shows the plug and the hole in the cam shaft where is should go.
IMG_3269_R.JPG
IMG_3271_R.JPG
Just an over-all view. Of course I had to pull the whole front end off. Not too bad though. I've ordered the plug as well as all new gaskets, clutch plate, bushings etc. Still considering poa. May try to use the OEM plug with loctite. Monitor oil pressure. Will keep you posted.
 
Last edited:

LRP

New member
Sep 29, 2010
202
0
0
canada
Sorry for the late response. First image shows the plug and the hole in the cam shaft where is should go.
View attachment 2291
View attachment 2292
Just an over-all view. Of course I had to pull the whole front end off. Not too bad though. I've ordered the plug as well as all new gaskets, clutch plate, bushings etc. Still considering poa. May try to use the OEM plug with loctite. Monitor oil pressure. Will keep you posted.
i would try a file on the end of the cam first. just a little stroke to see if it will file. if the file don,t cut it it won,t tap. if u can tap magnatize the tap
so it will contain the chips and remove oftem and blow clean with a air hose.
regards Louis