www.iFourWinns.com

I have a 1996 Sundowner 205, 5.1L, fuel injected engine.

Just pulled it out of (indoor) winter storage. The engine fired up just fine, in water no issues, power good, temp good. BUT the Oil Pressure Gauge is bouncing around. At idle it'll bounce between 50-30, under load it goes to 60+ and stays there, then after a few minutes starts to back down and then start bouncing around. between 60 and 30. At the dock it sometimes sits around 40 then starts bouncing again.

Oil pump? Gauge? Sender? It's the original Four Winns dash (so the trim gauge does not work)(despite a new sender)(wasted $$).

Anyone have any experience with this. Engine did not overheat, stayed below 150 the entire test run, which lasted about 30 minutes.

Thanks for any advice. I have lots to learn. Every year it' something new.

Mark

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Four Winns 1996 Sundowner 205
5.0fi/SX engine (Volvo Penta)

Some pressure gauge changes or fluctuations can be expected. If you are concerned, you could hook up an additional direct reading pressure gauge. Lower pressure is expected when the engine has warmed up, due to oil viscosity. Oil flows easier when it is hot. This pressure drop off is more common when the engine has more hours due to engine bearing wear. As long as you always have a pressure indication at idle, and the oil pressure is within operating parameters at cruise you should be fine. You should be able to check the owners manual for correct operating pressures. The pressure gauge fluctuations may be caused by the oil pressure relief valve or other conditions including electrical connections.

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Surface Interval: A scuba diving term for that time between dives to relax and prepare for life's next great adventure.

Current boat: '02 FW 268 Vista
Previous boat: '95 FW 190 Horizon

Thanks for taking the time to read and reply. It is very helpful. I may have not described it properly. -- when I say bounce I mean BOUNCE. The needle agitates from 60 to 20 and back and forth. Rarely does it stay in one place long - it'll go from 60 to 20 and to 50 and 40 in the blink of an eye. It's like a trapped bird. I am thinking it is the sending unit starting to go. I have no idea on the engine where this is. It's a FORD engine (mustang, I am told) with the marine modifications.

I just ran it in the driveway for about 30 minutes and the needle was flopping, but the engine sounded perfect (exceptionally quiet) and the temp sat at 145 without budging, more evidence, to me, that this is a sender unit (or VDO dash) issue.

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Four Winns 1996 Sundowner 205
5.0fi/SX engine (Volvo Penta)

I had the same Ford 5.0 EFI engine on my old '95 190 Horizon. I put over 2100 hours on it, and it still ran great. I am guessing it is either the sender, the gauge, or wiring. I would start with the wiring. Four winns did have a habit of using wiring that may have worked when new but did cause some issues later on. You might try an additional temporary ground from the battery to the ground terminal on the bus bar under the dash or to the gauge cluster. Check all connections. If that is all OK I would replace the sender. If that doesn't fix it you might look at the gauge cluster. There are a couple places that repair them. You can do a search on this site for those places. While it is difficult to trust an erratic gauge, the readings you are getting show that you do have pressure.

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Surface Interval: A scuba diving term for that time between dives to relax and prepare for life's next great adventure.

Current boat: '02 FW 268 Vista
Previous boat: '95 FW 190 Horizon

Thanks for the great tips. Where on this engine would I look for the sender? The dash is easy to access from behind, but I wouldn't know where to look for the sender unit on this particular engine block.

2100 hours!? I barely have 475 after 22 years! I gotta get out more.

You are very kind to help me out. Looking forward to getting in these weeds and solving this.

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Four Winns 1996 Sundowner 205
5.0fi/SX engine (Volvo Penta)

I don't recall, and would have to do some research. I would recommend buying a service manual (Volvo, Clymers, or other brand for hte Volvo). Over the last few years there has been a site or two that had all the service manuals. I don't see any now. Sorry I don't have a better answer.

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Surface Interval: A scuba diving term for that time between dives to relax and prepare for life's next great adventure.

Current boat: '02 FW 268 Vista
Previous boat: '95 FW 190 Horizon

Yes, that is the one I was referring to. Thanks,

_________________
Surface Interval: A scuba diving term for that time between dives to relax and prepare for life's next great adventure.

Current boat: '02 FW 268 Vista
Previous boat: '95 FW 190 Horizon