oil press gauge dancing
 

2000 hp500efi with a procharger,runs good ,burns excessive oil (1 qt per 10 hours)I recently bought the boat so running hours is unknown,at idle oil press is 20psi 3000rpm press is 40 psi ,over 3000 rpm gauge starts dancing between 10psi and 30psi sometimes bouncing to as low as 5 psi but the needle is never steady untill i lower rpms below 3000.Oil change has been done with no change 20w50 synthetic

I would buy a mechanical gauge and see what happens. I had the same problem (still do) and double checked it to find there was nothing wrong other than the fact that I have problems with my electric gauges. I'm on my second one from Gaffrig and plan on sending it back for a replacement plus I'm going to order new sending units.

I don't have 500 efi's but I have had a similar problem on my 502 Mags.

1 quart per 10 hours sounds about normal for me.

My dancing gauge was due to a poor conection in the mercruiser wiring harness. I have a quick disconnect junction in the wiring harness on the engine. (It separates the engine wiring harness from the boat harness)

I pulled the connector apart, spread all of the pins a little bit to ensure a solid connection and put some dielectric grease in for good luck. I have not had a problem since.

Steve

I am not an expert but I am sure:
smthng is wrong with your gauge/sender or fittings

I had a problem with one of my oil gauges. It was reading 50 then I look again it was reading 5 than 0. I slowed down real quick to 1500 rpm and it read 50 again. I turned engine off looked around sender found it was loose on the terminal. Tightened it up and never had a problem. I thought for sure major motor problem.
Rich

I had the same problem,,,,, new sending unit = 70 PSI!!!!

I had a similar problem. A new Gaffrig sending unit did the trick.

If you run a BBC hard it is not uncommon fo rthem to use alittle oil. 1 qt every ten hours is not to bad unless you are babying it. HP with a procharger I doupt that is the case. :D How many hours are on motor?

mechanical gauge
 

Does anyone use mechanical gauges? Dwight

Don't know about the pressure. But my Merc owner's manual states that oil use is not uncommon after hard running.

I have owned my boat for one year. It had 197hrs on it when I bought it, has 267hrs now. I have only seen oil use one time in that year, after a weekend of hard running.

Buck
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