high oil pressure at idle
 

Recently lost oil pressure in one of my engines at idle. Shut it down right away and found about five quarts of oil in the bilge. Found the source to be a cracked fitting.

After replacing the fitting and refilling the oil, I have had high oil pressures at warm idle. Cold start and above idle oil pressures are similar to unaffected engine (about 60 psi), but guage says 40-44 psi when returning to warm idle while other motor is 20-24 psi. These pressures are distinctly different than prior to loss of oil from the broken fitting. I have replaced the sending unit with a new one with same results.

I wondered about collapsed oil filter(?). I am going to try replacing the oil filter (WIX Racing) to see if it corrects the problem.

I will then try a mechanical guage to see if electrical readings are accurate.

Any other ideas or suggestions?

Re: high oil pressure at idle
 

40-44 at idle is more normal. I would look at the one with the 20-24. It seems low to me. Do the mech gauge, that will qualify the situation.

Re: high oil pressure at idle
 

Oil pressure before the incident was 20-24 at hot idle, always has been, 5 years on both engines. Something changed when I broke the fitting and pumped most of the oil out of the engine. If I scored a bearing or other damage from running with low oil pressure, I would have expected a relative drop in oil pressure. But the oil pressure went UP! Something is not right.

Re: high oil pressure at idle
 

Be sure to check the hose that you put into the fitting as well. Sometimes when you tighten up the hose in a new fitting they like to spin with the nut. I had one do this when I re-rigged an old 465. When I thightened up the hose, the brass hose end spun and actually collapsed. Lucky for me I seen it do it was able to replace it with no other harm done.

Just my .02 ...

John :D

Re: high oil pressure at idle
 

The fitting was just a small extension on the oil pressure safety sensor to get it away from the block for clearance. It has been eliminated.

Re: high oil pressure at idle
 

did you try the mech gauge yet.. on both? It doesnt seem logical, like you say??

Re: high oil pressure at idle
 

Just worked four straight night shifts in a row and haven't had time to dink with it yet. On my way out now to find a Super Duty MF oil filter wrench ... bend my standard one trying to get the GD#*%! filter off. :(

Geuss I might as well pick up some fittings/line for mech oil pressure guage while I'm at it!

Re: high oil pressure at idle
 

This my be a stupid question but you did put back in the same weight oil?

Also is the opening in the fitting you used the same size as the one you took out. 24 seems low to me as well.

A scored beering could raise pressure. It could give you less clearance and raise pressure.

Re: high oil pressure at idle
 

Same oil Mobil 1 15W-50. Was 24-25 psi hot coming off hard run, always has been. This is hot idle in gear at 450-500 r.p.m.

Broken fitting between warning buzzer sensor is deleted, now threaded directly to block.

My gut is telling me this is likely a guage problem. I'm going to put a fresh filter on, then change guages side to side to see if it follows the guage. This will be easier than putting a mech guage on temporarily.

Engine ran fine all day Saturday. I think I would have seized or melted down if it was a scored bearing.

Thanks for all your input ... I will post findings when I get more time to investigate further.

Re: high oil pressure at idle
 

This is actually not a stupid question.

Motors were out this winter for upgrade to Stef's pans, fresh oil pumps, thermostatically controlled oil coolers, and oil pressure reliefs.

Motors were dyno'ed on natural oil (? wt). Pans were then drained and refilled with the Mobil 1 15W-50, but there was probably considerable residual natural oil left in lines, cooler, and filter. So what I pumped out was a blend of natural and synthetic replaced with synthetic.

Any opinions if this would make a 15# difference at hot idle?

Maybe I need to change out the oil in the other motor!

And maybe I'm going to own Leathl WS6 a couple cold one's if I get to Cleveland this summer! :D

Re: high oil pressure at idle
 

Was the oil pressure on the dyno with the remote cooler and filter hooked up? You will loose 15lbs of pressure through all of the remote stuff.

Another thing to check is the oil line routing. Make sure they are ran correctly. If you have the oil lines reversed that will eat up 20 lbs or so. If you are running the WIX filter with the anit drain back your cooler will actually be cool while running. The drain back will not allow oil to flow through it backwards. All oil will be going through the bypass.

Which pumps did you put in? Are you running the HV pump or the standard pump. 24 seems way to low for new pumps. Did you have the correct pickup's put in for the pans you are using and did you have the clearance checked.

I'm betting on the oil lines being reversed.

BTW I'm actually from Amherst, which is in Lorain County. So I'm closer than you thought. Do you make it to the Islands much?

Rob

Re: high oil pressure at idle
 

Motors were dynoed with all rigging in place. I need to get the dyno sheets to check oil pressures.

Pans, pumps, rigging, and dyno all done by Sterling, so I have reason to believe everything is correct. Also everything is identical externally when comparing motors. Again, had no issue until the fitting cracked (I did the fitting a few years ago, not Sterling).

I do get to P.I.B. and Kelly's Island frequently. Also have a brother who lives in Bay Village. Perhaps we will cross paths this summer!

Chris

Re: high oil pressure at idle
 

Ok here's a thought.. If you are refering to the oil passage I think your talking about I may have figured it out. Are you refering to the opening on the back side of the motor half way up by where the bell housing mounts?

If so this passage is kinda small and close to the outside casting of the block. For that reason the extension that merc puts in there has a very shallow thread, (it does not go into the block very far. If you have just eliminated this extension and put the sender directly into the block it's possiable the sender protruding too far into the passage, blocking some of the flow. This would cause higher oil pressures.

Try to get a small pipe plug a shallow one from any hardware store and replace the sender with the plug. Make sue it is not past the threads in the block.

Rob

Re: high oil pressure at idle
 

Hey reddog were you planning on going on the sandusky pokerrun listed in the gatherings fourm?