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Problem with my oil pressure


steedbaff666

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Hi!

I have a Wakesetter 23 XTI 2003 with a Corvette LS1 engine. Last summer I had some problem with my oil pressure. In normal condition, the oil pressure is fine, but after the engine has been working hard for a while, and I shift it to idle, the oil pressure drops dramatically, until I hear the buzzer (sometime near to 0 pressure!!). The engine still runs properly and no problem with the engine temperature. All I had to do is increase the throttle: the oil pressure goes back up and buzzer stops. Then everything is back to normal. My mechanic tried to recreate this problem when I winterized the boat, but he was unable to do so: the pressure was still perfect!!

Do you think changing the oil sender and the gauge will be enough to resolve the problem??

Thanks

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Yes - to the question [replace the sender?].

This can also be an issue running wrong viscosity of oil. What grade are you running?

In my experience, the GM350 block runs notoriously low oil pressure at idle. I had a boat with twin 350's that would drop to 4psi when I would throttle back and come off plane. Alarms - just like your explaining. The only reason I bring this up - it was a twin setup. So I had two engines doing the exact same thing and was able to find comfort in that.

Same as you - I'd give it a little bit of idle speed and pressure would come back up over 10. Uncomfortable - but consistent with two engines side by side.

If you find out how to solve it, I'll be interested to know.

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Yes - to the question [replace the sender?].

This can also be an issue running wrong viscosity of oil. What grade are you running?

In my experience, the GM350 block runs notoriously low oil pressure at idle. I had a boat with twin 350's that would drop to 4psi when I would throttle back and come off plane. Alarms - just like your explaining. The only reason I bring this up - it was a twin setup. So I had two engines doing the exact same thing and was able to find comfort in that.

Same as you - I'd give it a little bit of idle speed and pressure would come back up over 10. Uncomfortable - but consistent with two engines side by side.

If you find out how to solve it, I'll be interested to know.

I don't know the grade of oil because I bought the boat last summer!!! Do you have a grade to suggest??

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I don't know the grade of oil because I bought the boat last summer!!! Do you have a grade to suggest??

I would use 20-50 racing amsoil,or 15w-40 marine amsoil their both great!

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Yes - to the question [replace the sender?].

This can also be an issue running wrong viscosity of oil. What grade are you running?

In my experience, the GM350 block runs notoriously low oil pressure at idle. I had a boat with twin 350's that would drop to 4psi when I would throttle back and come off plane. Alarms - just like your explaining. The only reason I bring this up - it was a twin setup. So I had two engines doing the exact same thing and was able to find comfort in that.

Same as you - I'd give it a little bit of idle speed and pressure would come back up over 10. Uncomfortable - but consistent with two engines side by side.

If you find out how to solve it, I'll be interested to know.

Mine does the same thing, tried a thicker oil but the pressures stayed the same. I went back to the recomended viscosity with the last oil change. Also tried an extra qt of oil, no change in pressures just the amount of oil on the dip stick. Let us know if you find anything out on how to fix the issue. Motor runs great with almost 500 hrs.

REW

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I would install a mechanical gauge with any oil pressure issue before I tried to diagnose anything. It is true though that engines can live a long time with low oil pressure at idle. Not good for the sbc cams though.

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I don't know the grade of oil because I bought the boat last summer!!! Do you have a grade to suggest??

Have you changed the oil since you bought it? There's no telling how long it's been since the previous owner changed it.

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Have you changed the oil since you bought it? There's no telling how long it's been since the previous owner changed it.

:plus1: I would go ahead and change it. especially if it sat all winter with the same oil from last year. I use Rotella 15W 40 and haven't had a problem.

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An extra quart of oil in the crank can lead to frothing of the oil due to the crank whipping the additional oil within the crankcase. This will aerate the oil, raise oil temperature and lower oil pressure. Ensure the dipstick is the correct length.

If the oil is unknown, I would certainly change it and the filter. Thicker viscosity oil will increase oil pressure, engine speed will also do the same thing. The higher temps from working the engine lower the oil viscosity and the oil pressure. Before changing from the recommended oil grade, I would change to manual specs and see how it runs, there is the potential the current oil is contaminated or diluted, thus giving the resulting low pressure readings.

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An extra quart of oil in the crank can lead to frothing of the oil due to the crank whipping the additional oil within the crankcase. This will aerate the oil, raise oil temperature and lower oil pressure. Ensure the dipstick is the correct length.

If the oil is unknown, I would certainly change it and the filter. Thicker viscosity oil will increase oil pressure, engine speed will also do the same thing. The higher temps from working the engine lower the oil viscosity and the oil pressure. Before changing from the recommended oil grade, I would change to manual specs and see how it runs, there is the potential the current oil is contaminated or diluted, thus giving the resulting low pressure readings.

I bought it in a Malibu dealer who always take care of the boat... The engive have only 200 hours... The oil was brand new when I bought it, I saw it on the stick... I will change the oil and the filter before my first run...

What is most likely? A problem with the sender or with the oil? My mechanic think that the bearing connecting rod and/or bearing crank are worn!!!

What do you think about that?

Thanks

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Take an oil sample and have it analyzed. This has been discussed on this board in the past. It will tell you if you are getting bearing damage. As Woodski has mentioned I would consider going up to a higher viscosity oil if the level is good.

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Take an oil sample and have it analyzed. This has been discussed on this board in the past. It will tell you if you are getting bearing damage. As Woodski has mentioned I would consider going up to a higher viscosity oil if the level is good.

:plus1: I would do the same.

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My engine, 2004 340 Monsoon - 400 hours, does the same thing. I've had 3 different grades of oil. When I first engage the throttle I'll get the beeping due to low oil pressure, I just put on the throttle and it goes away.

I figured it's just part of life.

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That is normal for Chevy engines, the oil pressure fluctuates with the engine speed; even Chevy cars and trucks do that. It's the way that the oil pump's are designed on Chevy V-8's.

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