mercruiser 140 manifold/ware in oil

[jimmytee]

I'm getting some water in the crankcase on my Merc 140. Pulled the head and it checks ok at local machine shop. How can I check if the manifold is ok? Is it possible a bad/cracked manifold would allow water in the crankcase?

 

[Haut Medoc]

Re: mercruiser 140 manifold/ware in oil

Pressure test it.....
If you have a cylinder with bad rings, water could seep past the piston from a bad manifold.....
How long did it take to get a noticable oil/water mix?......JK

 

[Bondo]

Re: mercruiser 140 manifold/ware in oil

Ayuh,.........

Is it picking up the Water as it's Running,..??..??.....
Or,......
Is the Water showing up during the times In-between the Runs,..??..??.....

If it's getting Water while Running,........ I'd think you have a Cracked Block...........

If it's picking up Water while Sitting,....... Then I'd look to the Manifold..........

Are Any of your Sparkplugs Extremely Clean,..??..??......

 

[jimmytee]

Re: mercruiser 140 manifold/ware in oil

what do you mean by pressure test? Compression test the cylinders? They seem to all be within range and all cylinders fire. It doesnt take long, maybe 4-5 minutes to get a noticeable amount of water in the pan. I've been told the block is cracked, but before I go to far, I want to eliminate every other possibility.

 

[ziggy]

Re: mercruiser 140 manifold/ware in oil

take yer manifold off and fill the waterjacket with water. see if this happens.

i left the waterjacket full overnight. next day the entire exhaust runner was full of water, right up to the brim....

 

[Bondo]

Re: mercruiser 140 manifold/ware in oil

If you're getting that much Water,..... That Quickly,.....

The Block is Cracked Inside the Crankcase............

Cracked Manifolds can only pass Water into the Crankcase when it's Not Running........


Btw,....... They're talking about Pressure Testing the Manifold's Water Cavity,........
Not the motor's Compression......