Blown head gasket?

[Danny93]

Hello, I have a 2000 Startcraft Aurora with a Merc 4.3.
The other day I went out and the boat seemed to lack of power.
Tooke it back to the storage and when tried to start it to flush the engine it never started, it crank and feels like is about to start but it never does.
I noticed some white-ish smoke coming out of the two valve cover tubes that go to the carb flame arrester so I immediately thought I had a blown gasket.

I have read different opinion on weather some moisture is normal or not so I decided to take the valve cover and intake manifold off and took some pictures.
is this normal or should I start pulling it all apart?

Thanks
Danny

 

[Danny93]

one last thing, the oil from the dipstick looks fine, didn't find any white sludge or sign of water there.

thank for your help.
Danny

 

[Watermann]

Danny your questions would get the most bang for it's buck in the Mercruiser section so maybe a mod could move the thread for you.

Have you drained the oil out of the pan yet and of so how did it look? I would think if you had water intrusion there would be a milkshake look to the oil in the pan as well. The lifter valley doesn't look like there was any of the white milky stuff in it but obviously there is some water in the motor that looks to be more than just condensation.

I've seen guys motors run while ingesting water so I'm not thinking that white mess in your valve covers in of itself would cause the motor to not fire up. I would have pulled the spark plugs first and done a compression check to find out if there was a cylinder not holding if I suspected a bad head gasket or had an overheat with lack of power but I guess you could still do that and report back what you find.

 

[GA_Boater]

Danny - Moved this to the Mercruiser section so you have a better shot at the right advice. Hope it's not serious.

 

[carrier82]

Water is getting in the oil for some reason. Blown gasket wouldn't be my first guess, but a cracked block or a leaking manifold.

 

[flipbro]

Change out the intake gasket. Then do a pressure test on the cooling passages. If it holds 12 psi for an hour. Then do a commpresion test if that checks out change all the filters check timming and hopefully go boating.. Good luck

 

[Danny93]

thank you guys, well a mechanic and boat buddy managed to start it. Ran very rough, and white smoke from the exhaust which by intuition and experience he said there is definitely water leaking in the pistons either from a cracked cylinder or bad gasket. Exhaust manifold seem to hold up water good so could also have been the intake manifold. Long story short, I found very bad (consumed?) head gaskets. So I hope that all it is and no cracked cylinder.

I put new gasket and about to put back on the heads but now I found on the manual two options for bolt tightening torque: Gen +uses a degree after first pass, all others use 3 pass all the way to 65 foot pound. How do I know which one I have?

Should I start a new thread?

thanks
Daniel

 

[Bondo]

Ayuh,.... You have the Gen +,.....

Keep usin' this thread, so yer info is all together,......

 

[Danny93]

thank you Bondo, I guess I have to buy a degree wrench!!
How do you know it is a gen+ by the way? is it the balancer?

 

[stopher8]

I just did head gaskets on my 1994 4.3LX. The 96 and up is degree after ft lbs. The 95 and back torques to 65lbs. I would use new head bolts and I'd wire brush the cumbustion chamber really good and search for cracked head. The machine shop told me the 4.3s crack really easy. Both of mine were cracked. Good luck either way.

 

[Bondo]

Ayuh,.... The big changes in the 4.3l were in the '90s,.... by 2000 it's the late model,...

 

[Danny93]

thank you guys.

 

[NHGuy]

You shouldn't need a degree wrench for 180 90,45, 22.5 etc degrees.

 

[NHGuy]

How far do they turn after torque?

 

[cliffblue]

Hello Danny,
I went through this a couple of years ago on my 2001 4.3. I found an inexpensive degree gage on eBay. The reference section on this site is indispensable for mechanically inclined diy boat owner. Good luck.

 

[Danny93]

thank you so much guys, you have no idea how much these forums help!!!!
I have put new gaskets in, and bought an inexpensive degree torque gauge at the local auto part store for $12.
The heads are in and I have memorized, not my choice, the torque/angle and sequence of each bolt and I am pretty satisfied with the results so far.
While putting on the Intake manifold I made a mistake I guess at reading the manual and torqued the intake manifold bolts to 35ft/lbs which caused them to brake.

I noticed then at the beginning of the manual, these bolts should be set at 11 ft.lbs ( 133 lb inch).
So now I am one bold short and need to know if I can use any bolt (of same size and thread) or do these have specific characteristics?

cheers
Danny

 

[Bt Doctur]

The "torque -to -yield" and the regular torque readings are almost the same. The degree method has you placing a mark on the head of the bolt and turning it an additional amount in degrees. Use the Ft / Lbs and you`ll do just fine.

 

[Bondo]

I noticed then at the beginning of the manual, these bolts should be set at 11 ft.lbs ( 133 lb inch).
So now I am one bold short and need to know if I can use any bolt (of same size and thread) or do these have specific characteristics?

Ayuh,..... So long as it's a gr. 5 or better,....

 

[Danny93]

One last thing please, valve lash adjustment: the manual says I do not need a valve lash adjustment for the 4.3 Gen+. it says the lash is correctly set when the fasteners are set to specification.
I tried to torque them to specification but it looks like the bold basically just tightens all the way down before the click and it compresses the valve spring quite a bit too.
Is this right?

 

[Bondo]

Ayuh,.... How tight are ya torquin' 'em,..??