1995 Seaswirl 4.3 OMC V6 - Oil Change - Temp

[TyeD17]

Hello Guys,


I have a quick question for winterizing and changing oil in my OMC 4.3.

Does anyone know what oil I'm surpposed to use? I usually do a 10w30 but......I have noticed my engine running about 10 -15 degrees hotter this summer......and taking a long time to warm up..........would oil make this much of a difference......Thanks. and which would you use for the motor.


Tye

 

[bruceb58]

The temp has more to do with your thermostat and raw water pump. How old is your impeller? If 3 years or older, replace it.

 

[Lou C]

OMC originally recommended a straight 30, but many use 15/40 or the Merc 25/40 which is a marine certified oil. The impeller is easy to replace on the Cobra. It is under the plastic cover at the end of the upper gear housing, if you have the original dog clutch version, the later version made with Volvo in the joint venture has the impeller on the engine, just like other Volvo engines, that's probably what you have judging by the year...

 

[TyeD17]

The temp has more to do with your thermostat and raw water pump. How old is your impeller? If 3 years or older, replace it.

OH that baby is on her last leg 4 to 5 years.... She is going this winter ......I'm still wondering about the oil though.

 

[TyeD17]

OMC originally recommended a straight 30, but many use 15/40 or the Merc 25/40 which is a marine certified oil. The impeller is easy to replace on the Cobra. It is under the plastic cover at the end of the upper gear housing, if you have the original dog clutch version, the later version made with Volvo in the joint venture has the impeller on the engine, just like other Volvo engines, that's probably what you have judging by the year...

I might sound crazy but i think i remember talk with someone and them saying there was an impeller on the engine and one in upper housing.

 

[Horigan]

A '95 will be a OMC/Volvo joint venture design where the raw water pump is a belted engine accessory pump on lower starboard side of the engine. There will not be a pump on the upper gear case of the drive.

I would run 15w-40 weight oil for diesels. I've run 30w also with no issues. Plenty of opinions on this subject...

 

[Scott Danforth]

I might sound crazy but i think i remember talk with someone and them saying there was an impeller on the engine and one in upper housing.

that is crazy.... I want what that person was smoking

 

[Lou C]

That's wrong of course but the confusion may come from the fact that there was an OMC Cone Clutch drive similar to the Volvo (King Clutch Cobra) but it had the impeller in the upper gear housing like the smaller dog clutch Cobras.
If you have the drive that is flat across the top, it is the old style pure OMC Cobra with the impeller in the upper gear housing as in my pix above, if it has a hump on top like a Volvo SX then its got the engine mounted impeller. I have never done the Volvo style on the engine one but the on in the upper gear housing, is about as easy as it could be. 15 min job.

 

[southkogs]

I might sound crazy but i think i remember talk with someone and them saying there was an impeller on the engine and one in upper housing.

There are circulation pumps in the engine (water pump) and impellers in the drive on many/most I/O systems. There are a few that aren't like that. I've made the mistake of assuming before.