Mercruiser 4.3 lx - residual oil collecting on intake

[Trooper583]

Hi all, I have 2003 mercruiser 4.3L in 21' OB that I'm having an issue with. I have noticed this over the past few years and would like to see if there is a fix. I have noticed that a small amount of oil collects on my intake. I presume that this is from vent hoses that run from the valve covers up to the spark arrestor. I have examined the microfiche from mercruiser and compared it to my set up and it appears to be identical. Is this oil collection normal? After a season of running I have only about a couple of tablespoons sitting around in the depressions in the intake. I have also noticed while looking at my engine run at night with a flashlight, you can see the oil vapor coming out the tubes. Ideas? Suggestions? Thanks in advance.

 

[Bondo]

Re: Mercruiser 4.3 lx - residual oil collecting on intake

Hi all, I have 2003 mercruiser 4.3L in 21' OB that I'm having an issue with. I have noticed this over the past few years and would like to see if there is a fix. I have noticed that a small amount of oil collects on my intake. I presume that this is from vent hoses that run from the valve covers up to the spark arrestor. I have examined the microfiche from mercruiser and compared it to my set up and it appears to be identical. Is this oil collection normal? After a season of running I have only about a couple of tablespoons sitting around in the depressions in the intake. I have also noticed while looking at my engine run at night with a flashlight, you can see the oil vapor coming out the tubes. Ideas? Suggestions? Thanks in advance.

Ayuh,.... That's combustion blow-by,... Do a compression, 'n leak-down test,....