Oil pressure & turbo boost

[Ron Sillaman]

Took possession of a 2007 Sundancer 40 with QSB 5.9 380 hp in December. Engine survey was excellent. Launched boat in March. First few times out engines performed perfect. Last time out the port engine oil pressure read 6 or 7 psi less than starboard engine. Turbo boost also was reading less. Any suggestions? Boat ran fine. Analog readings on dash and vessel view numbers matched

 

[Shaps]

FWIW,
i always have between 6-8 psi difference between my engines.
It was explained to me that is caused by the extra hosing required to relocate the oil filter on one of the engines.
As long as it remains consistent i think you are ok.

 

[dtfeld]

How far off was your turbo boost? A psi or two could be guage error, or a conversion error if reading g digital, or a combination of the two.

 

[LG111]

Try this, sometimes the system glitches. Turn the keys or switchs to ignition but not starting. Pause for 15 seconds or at least until the computer is fully up and running. Then start the starboard first then Port. See if boost matches. Oil pressure will always very between engines.

 

[Ron Sillaman]

Try this, sometimes the system glitches. Turn the keys or switchs to ignition but not starting. Pause for 15 seconds or at least until the computer is fully up and running. Then start the starboard first then Port. See if boost matches. Oil pressure will always very between engines.

Followed your advice. Readings were opposite. Starboard engine was showing lower oil pressure and lower turbo boost.. How do you fix?

 

[LG111]

How much lower between turbos? My oil difference is around 56 and 48 at cruise always been that way.

 

[LG111]

If pressure is a wide gap between boost, then look into the waste gate.

A wastegate is a valve that controls the flow of exhaust gases to the turbine wheel in a turbocharged engine system. ... The primary function of the wastegate is to regulate the maximum boost pressure in turbocharger systems, to protect the engine and the turbocharger.

 

[dtfeld]

If your boost is off, you will notice other problems. Likely lower power, and black smoke coming from lower boost engine. Any other symptoms?

The easiest way to confirm is get a good set of mechanical gauges on the engines and measure the boost. You can determine if it’s in spec, and also confirm if it’s gauge error.

While your down there inspect and hoses, pipes and clamps from the turbo outlet to the manifold.