Head Gasket / Milky Oil

[fishrdan]

- Are you cleaning the head bolts, wire brushing off the old sealant?
- Are you running a tap through the block threads to clean out the old sealant?
- What is your timing set at? (as BtDr mentioned).

I would use a FelPro head gasket. I always use FelPro when possible.

Mercruiser has a service bulletin for 3.0l blown head gaskets, earlier year, but it indicates that too much timing will blow head gaskets. Your boat is a 2001, but the engine could fall into this serial number range.

http://www.boatfix.com/merc/bullet/98/98_14.PDF

 

[Bt Doctur]

too much heat and too much advance will do it every time

 

[Jon1229]

too much heat and too much advance will do it every time

Thanks, the engine usually hovers around 150 degrees, is that considered normal?

 

[Bt Doctur]

with a 140 tstat ,yes

 

[Jon1229]

with a 140 tstat ,yes

Thanks, so that takes out overheating, the surfaces are flat I got them milled by a machine shop, so that only leaves timing... is there anything else it could be besides that just so this time when I put it back together it’s a permanent solution? If I put the engine back together with a new head gasket, can I bring it to the local shop to have the timing issue fixed or will they have to take the engine back apart to do that?

 

[Benny67]

-I would use a FelPro head gasket.

Totally agree with that one...

Obviously you really need to examine that particular spot. There's something you are missing either on the Head or the block.

Take a day off from the problem and go back to it with a fresh mindset.

Maybe use a good metal ruler to see if there's a dip you missed in that area.

Maybe also use a 3M pad to clean both surfaces and give it a good wipedown with acetone before installing the new gasket.

 

[Bt Doctur]

If you prep the surfaces first, inspect for any warpage, install the head correctly by torque pattern and in 3 or 4 steps to 90Ft.Lbs ,have the timing set correctly, the motor should live just fine.
Abusing it, screamin at 4500 rpm, yanking tubes of people up is not conductive to longevity

 

[Jon1229]

Thanks everyone, I ordered a new felpro gasket i will try it this weekend

 

[Bondo]

Abusing it, screamin at 4500 rpm, yanking tubes of people up is not conductive to longevity

Ayuh,...... Ethanol, 'n no canister fuel filter can easily set up detonation too,......

 

[scoflaw]

All 3 gaskets blew in the same spot ? If yes, you got more than a timing issue

 

[Jon1229]

All 3 gaskets blew in the same spot ? If yes, you got more than a timing issue

Yes, all three. What would you expect the problem to be?

 

[Jon1229]

- Are you cleaning the head bolts, wire brushing off the old sealant?
- Are you running a tap through the block threads to clean out the old sealant?
- What is your timing set at? (as BtDr mentioned).

I would use a FelPro head gasket. I always use FelPro when possible.

Mercruiser has a service bulletin for 3.0l blown head gaskets, earlier year, but it indicates that too much timing will blow head gaskets. Your boat is a 2001, but the engine could fall into this serial number range.

http://www.boatfix.com/merc/bullet/98/98_14.PDF

As for tuning a tap through the block, what is the exact tool I need and size of the tool?

 

[Bondo]

Yes, all three. What would you expect the problem to be?

Ayuh,..... Imperfections on the block, or head in that area,.....

 

[Jon1229]

Ayuh,..... Imperfections on the block, or head in that area,.....

Yeah I will check for imperfections but I did just have it Milled by a machine shop. Do you know what I would use to clean the holes in the block before I reinsert the head bolts

 

[Bt Doctur]

a tap or a chase for the thread size of the bolts being used, and wire brush the old bolts clean too
1/2 x 13 NC (national course)

 

[Jon1229]

a tap or a chase for the thread size of the bolts being used, and wire brush the old bolts clean too

Is there a standard size for the head bolts or would I need to take out a bolt and bring it to the store with me?

 

[achris]

Clean up the threads before you install the head. Yes, take a head bolt with you to the shop to ensure you get the right tap. Install the head bolt with sealant on it to stop water wicking up the bolt and mixing with your oil.

Once assembled, set the ignition system in 'base mode' and set the timing according to the manual.

Did you read the service bulletin?

Chris. ....

 

[Benny67]

Check your threaded holes to make sure you are not bottoming out on debris causing the head and the block to not properly seat together.

 

[fishrdan]

Use Permatex #3 Aviation Sealant to seal the head bolt threads.

I dip the bolt threads and brush of the excess, enough sealant so it's even with the bolt's thread tops. Then put a dab of sealant on the block threads, so the bolt pushes sealant down in front of it.

With blowing 3 head gaskets, I would run the engine up to temp and let it completely cool down, then recheck the head bolt torque. Better yet, re-torque the head bolts. From Fel-Pro:

Make sure the engine is at room temperature.
Drain the coolant (water).
Start at the first bolt in the torque sequence.
Loosen the first bolt about ½ turn.
In one motion tighten the bolt to the original torque spec.
Repeat this process one bolt at a time following the torque sequence.

 

[achris]

...., I would run the engine up to temp and let it completely cool down, then recheck the head bolt torque. ...

Iron head on an iron block. Head bolts need to be re-torqued hot, not cold.

Chris........