Dave1972

Ok....I winterized the boat and changed oil and noticed that the oil is a little "nasty" looking. This is the first oil change since a total rebuild. The oil is a little grey looking...almost as if there might be a little water in it? I didn't notice the oil level went up before I changed it/after I ran it. The oil has about 10 hours on it or so. I had some problems when I got the boat back and the EFI system was plugged with silt from the tank (at the VST tank and the injector screens). I changed the screens and the boat ran flawlessly after that. I did order an oil analysis test kit and should be coming today or tomorrow and they will tell me for sure. I was just curious if the cam/lifter lube is a different color and could have caused the oil to be a little discolored? The oil was just conventional petroleum based oil (not sure what weight) and it smells strongly of gas (fuel dilution?). I didn't make any changes to the fuel pressure or to the injectors (stock 502 EFI setup) but the ECM has been reprogrammed along with forged pistons, roller valve-train, slightly more aggressive cam than stock. Should I be worried or should I just wait for the oil analysis to tell me what the deal is? I spent a ton of money on a rebuild/upgrade and it's got me very concerned to say the least.

Any words of encouragement/advice?

Thanks,
Dave

Crazyhorse

Yes, the cam/lifter assembly lube can add a grey color to the oil. A slight amount of moisture from running in cold conditions can also change the color of the oil. I prefer to run an engine on the first oil (after a rebuild) long enough to satisfy the camshaft break-in requirements only. The oil and filter are then changed to reduce the chance of plugging the oil filter with the assembly lube. I commend you for taking the time to change oil and filter before winter storage. I know a lot of people that don't do it.

liquid lounge

Dave- Gas from the modified f/i is the most likely culprit...also happens in the HP500EFI. Carbon build-up on the pistons and chambers are likely to be more harmful than the gas in the oil. This rich condition is most prevelent at lower rpm's when the MAP cant get a stable reading due to intake reversion caused by a higher overlap cam. Keep your idle time to a minimum and change your oil often. Hope this helps somebody.

Dave1972

Crazyhorse,
That would make sense as this is the first time changing after the motor has been rebuilt. I also ran the boat when it was pretty chilly outside (44 degrees when putting in and not much warmer when taking back out 4 hours later).

The filter was a WIX 51061 and replaced with the same (Napa Racing 1061 made by WIX).

The real story will be told in a few days as my oil analysis kit came today and will be in the mail tomorrow.

Fire the boat up in the spring, get all the antifreeze out, change plugs, cap and rotor, change oil to synthetic, and give it another shot I hope is all I need to do. It just worries me that the oil is slightly grey in color and smells very polluted with gas!

Thanks for the replies....anyone else have opinions or feedback?

paradigm shift

Well I think you have gotten good advice. I would not panic and wait for oil analysis to come back.

Crazyhorse

I've never run FI and I think Liquid Lounge has got a good point.