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Blown head gasket

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Brandon Wojcik

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"Just tuned up my AQ131D and w

"Just tuned up my AQ131D and was surprised by the amount of white smoke/steam coming out. It was cold today 55 degrees but it still seemed like a lot. I ran it for 20 mins and it did not seem to diminish a whole lot. Head Gasket???? If so how much of a pain to replace and will it hurt to go fishing a short distance off shore tomorrow? I think I know the answer, I just want someone to say it is OK!"
 
"Do a compression test- if you

"Do a compression test- if you have one cylinder that's way low, it could be a bad gasket. I personally wouldn't go offshore if I thought I had a blown gasket.

Sorry to rain on your parade, but....."
 
"I agree with Jim N...
A blow


"I agree with Jim N...
A blown Head gasket can only lead to more trouble
I would consider yourself lucky that you caught it as soon as you did and go ahead and change the head gasket before it does get any worse and possably leave you adrift,"
 
"Before dismantling anything,

"Before dismantling anything, consider doing a leakdown test, or at least putting some compressed aair on each cylinder while at TDC at the end of the compression stroke. If you get air bubbles in your heat exchanger, then you know for sure you have a blown gasket or (more unlikely) a cracked head."
 
"I was told to take out a spar

"I was told to take out a sparkplug, start it up and look for water to diagnose a blown gasket. Is that good advice. I am confident that it is the gasket and plan to replace it today. Could this also explain the reason my engine kept running after I turned it off yesterday?"
 
"You may not always see a leak

"You may not always see a leak going into a cylinder, unless you pressurize the fresh water cooling side first. In any case, replacing the head gasket is not a big job.

I don't see how an engine can keep turning due to a leaky head gasket after turning off the ignition key."
 
"The question has never been a

"The question has never been asked and I don't recall any mention if the engine has been ran hot?
if in fact it has been ran hot, most commonly results would be a head gasket or cracked head as mention before, So like El said > before taking appart the engine I would have to ask myself 1-if I knew it ran Hot? 2- how the engine performed last time used? ............. Although
there are a couple of other reasons
that would cause a head gasket to blow besides the
ovheating, 2-corrosion
3- an improper timed engine along with improper adjusted carb. or carbs...................... When the engine continues to run, this may be due to pre-ignition
( dieseling /or spark knocking )
meaning: there are bits of hot carbon accumulating along the bottom of the head/valve
causing the fuel to " Pre-ignite "
this could have led to a blown head gasket as well.............
Or! are you saying that the engine literly runs smoothly as if the ignition switch still in the run position? if so! this would have more to do with the ignition switch itself.
and you forget all about the Preignition theory
crazy.gif
"
 
"I like the pre ignition theor

"I like the pre ignition theory as the culprit, is there anything I should look for or do when changing the head gasket. This website is the greatsest! You guys are awesome. On a teachers salary, I can't afford to bring my boat in for service all the time and I always have these little questions. Thanks for the help!!!!!!!!"
 
"Since you are going to remove

"Since you are going to remove the head, I suggest you examine the belt tensioner and the timing gears. If the gears are pitted, now is the time to replace them before they chew the timing belt. If they are OK, consider replacing the belt tensioner and the timing belt if you haven't done so recently. You can use automotive versions of all the above components, as they are identical to the "marine" components but cheaper. Also, you can get the sets of timing gears from a Volvo autowrecker for a fraction of the cost you would pay for the VP parts.

The torque for the head bolts depends on the type of head and the type of bolts you have installed. Most of the aftermarket gaskets specify which torque you must apply, and in how many steps. Theoretically, the AQ131D goes in 3 steps: 15 ft-lb, 29 ft-lb, then tighten another 90º.

You should also check the block surface and the head for warping, especially if you suspect overheating has taken place.

Finally, if you haven't done so by now, you may want to invest in a copy of the Seloc and/or Clymer repair manuals for your engine. It will be money well invested."
 
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