Maxum Boat Owners Club - Forum

Maxum Boat Owners Club - Forum (http://www.maxumownersclub.com/forums/)
-   Engines (http://www.maxumownersclub.com/forums/f12/)
-   -   Rocker cover gunk (http://www.maxumownersclub.com/forums/f12/rocker-cover-gunk-7484.html)

Marty87 06-07-2017 02:29 PM

Rocker cover gunk
 
2 Attachment(s)
Hey guys few weeks ago I posted about gunk in both rocker covers on my mercruiser 4.2L v6 (190) vortec well I've finally got home from work to starting working on it so far I have started up engine to run it to normal temp 175 then emptied oil out all came out clean oil with no contamination in the sump and then cleaned the rocker covers the best I could then added 4 litre of engine flush ran it on idle for 15 mins check oil stick and was crystal clear let engine sit for 30 mins then ran it again for 15 mins and was still Crystal clear but when running on idle on the breathers on the rocker covers was if steam was coming out so I'm getting water in somewhere I'm thinking either 3 things cracked blocked or inlet manifold gasket or the risers are letting water in to the pistons and pushing water up through valves anyone experienced this

speedysprocket 06-07-2017 10:35 PM

And you say you saw no water coming out in the oil?! That's looking pretty bad. I'd pull the heads and have them rebuilt. Putting them back on gives you new head, intake, and manifold gaskets. Only other thing is the block and that's probably lowest on list of likelihood.

Marty87 06-07-2017 10:53 PM

Yae no mixing in the sump only gunk in the rocker covers so my next move is testing the risers making sure they aren't leaking if they aren't then move onto inlet manifold gasket and check that and check for cracks underneath there if not then move onto the heads just can't see 2 heads goin at same time as I have gunk in both rocker covers

mmwjr 06-08-2017 01:14 AM

I'm just going to say good luck, the oil passages in the head are connected to the block passages and all drain into the pan.

IMO you are planning to spend a fair amount of money on a hope, I would just bite the bullet and replace the engine. You have been talking about this for over a month now and the season is passing you bye.

Marty87 06-08-2017 06:43 AM

I have a mercruiser specialist coming over this weekend to have a look see what his thoughts are, engine blocks over here aren't like states there much more expensive for new block they sell for 4000 plus and that just block no inlet manilfold or carb or exhaust risers or water pump just block only

mmwjr 06-08-2017 11:22 AM

Quote:

Originally Posted by Marty87 (Post 48892)
I have a mercruiser specialist coming over this weekend to have a look see what his thoughts are, engine blocks over here aren't like states there much more expensive for new block they sell for 4000 plus and that just block no inlet manilfold or carb or exhaust risers or water pump just block only

I understand about the cost as you posted it in your previous thread. You description is a long block; block, heads and all internals. A short block is the same less the heads.

I doubt the mercruiser guy will be able to tell much with out a complete disassembly and magufluxing the casting to look for cracks in the block and heads.

Marty87 06-08-2017 11:41 AM

Yae your right, but I'll see what his thoughts are before spending on new block

MAXUM2500SE 07-04-2017 11:33 PM

How did you make out Marty?

Marty87 07-06-2017 10:15 PM

Done compression test on all cylinders and results where cylinder 1 was 155 cylinder 2 was 157 cylinder 3 was 155 cylinder 4 was 65 cylinder 5 was 150 cylinder 6 was 170 so took off exhaust and noticed water in manifold then started taking inlet manifold off and the gaskets where fine and no signs of cracked block then taken off both heads and the head gaskets where fine but exhaust port on cylinder 4 was corroded and inlet valve and exhaust valve where corroded as well so wasnt seating properly and causing the low compression and letting water in causing the gunk in the rockers

mmwjr 07-06-2017 10:29 PM

The valves are bad because of burning water, I.e. Tuplid valves burnt seats. This happens due to bad exhaust that allowed water intrusion. The engines back pressure sucks water in through the exhaust valve durning the final degrees of the exhaust stroke. Compressing water forces it past the piston rings and into the crankcase where it mixes with oil.


All times are GMT. The time now is 02:44 PM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2018, vBulletin Solutions, Inc.