wilstruck

I purchased a boat at the end of last season (Baja w/ 496 mag)had it out a few times with same readings. First time out this season had same readings but alarm sounding after hitting a little mud. Oil temps dropped to 0 at idle and 20-30 at 3000 rpm, engine temp stayed at 160. Pulled boat out of water brought home hooked up to ears and oil back to 40 psi cold. 20-30 psi at idle when engine reaches operating temp of160. Whats the average oil reading for a 454 or 496?

Need to get it out again after flushing engine and see if alarm continues to sound. Should I be worried of these oil readings?


Will

redstinger

Yes, remote filter. Only about 150 hrs on the motor. My top end has dropped from 48 mph down to about 40 mph...maybe I am losing compression?? The previous owner had the boat way overpropped, 25 pitch. Maybe running 100 hrs with that prop hurt the motor...if you drove your truck uphill in 5th gear for 100 hrs the motor probably would be compromised.

redstinger

was able to get a mech gauge on it. same readings as the electric....30-40 psi cold, about 10-15 idle, warm oil 20 psi at fast idle...didn't even bother getting it hot.

no noise, engine runs good...top end is down about 5mph from last season though.

redstinger

changed oil again, added straight 50 valvoline, along with 2 qts of Lucas oil stabilizer. Pressure is steady about 20 psi when hot at 3000 rpm. Its 105 degrees here and I don't feel like pulling the motor until September. If I throw a rod then i guess I have an excuse to buy a 502 crate motor.

rumblfish1966

just my .02 cents worth but the motor is going away there is somethuing definatly wrong internally had quite a few do the same thing the previous owner/owners were usually ful of s#@t about how hard it had been run or how many hours or the quality of the last "rebuild" start running straight 50w ,cross your fingers and hope it holds together for ya

redstinger

UPDATE! Have had the boat out every weekend for the last 6 wks, still running strong....at 10-20 psi hot oil pressure!!! No noise from engine at all.

When I first noticed back in May that the oil press was running low, I also noticed a dropoff of about 10 mph on the top end. Power out of the hole still good though. it is possible that my lifters are not filling up with oil and therefore not lifting the valves, therefore no top end power?

redstinger

Boat still running. no noise from motor yet. yesterday 15 psi at 3200 rpm.

cloudmaster_321

I know when I had my oil up to 260 degrees the past weekend on 20w-50, i thought 41 lbs @5000rpms was a little low. Now i'm not so sure, sounds like it is normal for the temperature. Probably just need a better oil cooler.

redstinger

Well I made it to Labor day without blowing up the motor, so I pulled it a few wks ago to rebuild and stroke/bore to 489....my engine builder called me and said he could jiggle the crank up and down...he's never seen so much play !!! He said if I didn't rebuild when I did it would have blown up pretty soon!! No wonder no oil pressure. Bearings were ground own to nothing. 2 valve springs dead also. 489 with cam/valvetrain from RM builder will be going in next week. Going from a 454 runnning at 50% to a fresh roller 489...Lake is full, its going to be a great summer!!! Thanks for all the suggestions.

almalare

I have (2)factory rebuilt 7.4LX MPI engines that are 2 years old and only have 150hrs on them.My pressures are identical to yours.I had to replace a piston recently and I had a look at the rod bearing.It was perfect ..like brand new.I was a little concerned as well with 10 psi idle and 40 psi at 4400RPM but maybe when the 10 psi/1000 RPM rule was invented oil was not as good as it is now and of course we have synthetic now