Mercruiser 260 V8: Oil gushing out from dipstick

[Moor]

Need Help: Engine 260 V8<br /><br />Oil is gushing out of side vent hole at top of dipstick at medium to high revs. <br />There seems to be a lot of back pressure in engine but compression is fine on all cylinders.<br />This has just happened after cylinder heads had been re-installed after some valves had been replaced as there were pitted. Whats happening?????

 

[Trent]

Re: Mercruiser 260 V8: Oil gushing out from dipstick

Iv seen this before...Are you sure the head gaskets were not installed on the wrong side or upside down. It can cause this problem.

 

[Moor]

Re: Mercruiser 260 V8: Oil gushing out from dipstick

well now I am not sure! any way of checking without removing heads?<br />tx for the reply

 

[f_inscreenname]

Re: Mercruiser 260 V8: Oil gushing out from dipstick

Did you change your valve covers? If so,did you open the covers vent (where you put oil in at). The same thing happened to me when I installed new cover and breather (oil fill cap).The rubber that fits on oil filler cap comes from the factory closed. You need to cut the end off so air can flow free.

 

[Down South]

Re: Mercruiser 260 V8: Oil gushing out from dipstick

You are defiantly are having a high crankcase pressure problem. The crankcase vent is the first place to start. Is the vent open and clean? Does the vent exhaust to atmosphere or does it tie back into the carb or intake manifold? if it ties back into the intake pull the hose and check for restrictions, On some engines there is an orifice at the manifold that gets plugged pretty easy.

 

[Mish_Mish]

Re: Mercruiser 260 V8: Oil gushing out from dipstick

Sounds like it might be leaking exhaust into the crank case from one of the cylinders.<br />Happens when your heads were not torqued properly, or undertoqued, which it the same thing.<br />Start with measuring compression in all cylinders, it should tell you where the leak might be.

 

[Moor]

Re: Mercruiser 260 V8: Oil gushing out from dipstick

Ok found out why this was happening:<br />WRONG OIL!<br /><br />I put in a synthetic 0W-50W . too thin replaced with 20W-50W oil problem disappeared including excessive smoking at breathers.<br /><br />Mario