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Marine Engine help needed (Chevy 350)
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Posted by: Slow Nova

I know MMC isn't really the place for this, but what the hell, I'll give it a shot...maybe you guys can help me out.

Yesterday I was running the boat around for a few hours on the lake. after running from one end to the other (only about 5-7 minutes) at full throttle, I backed off the throttle to let someone else drive. as soon as the motor got to idle, it died. I tried to start it back up but it would just crank over. I figured it's flooded, so I gave it 5 minutes, and tried again...nothing. 10 minutes...nothing. At least I got towed back to the dock by a group of wakeboarders that were passing by. It fired right up when we got back to the dock.

Today I opened the engine compartment, and found about 1/2" of oil sitting under the engine, and some fluid on top of the intake manifold that had the color and consistancy of egg nog. I'm a tinkerer, not a mechanic...anyone know what this might be? I'm thinking oil/coolant or oil/fuel. Just last week a compression test was done, and all cylinders were making good compression, so I don't believe there's a blown head gasket.

Posted by: Mr. P

ggggg

Posted by: Slow Nova

Lookie what I found:

I just picked up a compression tester...I'll re-check the compression next weekend. Besides a blown head gasket, crack in the block/head, what could cause coolant to leak into the engine?

Posted by: VETTKLR

Oh shit, that's the dreaded milk shake!!! You milked it, didn't you, Focker!!!

You took out a head gasket, homie! Ok, be honest...you sprayed a 200 shot to get her outta' the hole quicker.

Posted by: Slow Nova

Someone's trying to tell me to try to put the blame on the shop that changed the water pump a couple weeks ago...could changing the water pump cause something like this, if it was done incorrectly?

Posted by: VETTKLR

I'm not sure what motor you run in that boat, but I doubt it, dude. Did you overheat it prior to replacing the pump?

Posted by: Slow Nova

Quote:

Originally Posted by VETTKLR


	I'm not sure what motor you run in that boat, but I doubt it, dude. Did you overheat it prior to replacing the pump?

The motor is a Chevy 350. about 500 hours. 15 years old. If I did overheat it, I wasn't aware of it...the temp gauge may be busted. I haven't smelled anything burning. I went ahead and brought it back to the shop to have them take another look at it. As it is, I won't have any time to spend with it until probably february.

Posted by: VETTKLR

Right on, keep us posted on the problem.

Posted by: Slow Nova

Just got off the phone with the mechanic. He said that he noticed when taking the intake manifold off that the bolts weren't as tight as they should be. This makes me wonder if the person (don't know who) that rebuilt the engine a couple years ago didn't torque all the bolts down correctly...or possibly didn't re-torque them...is this something that needs to be done on the 350? I know some engines need to be re-torqued after so many miles / hours.

Posted by: Slow Nova

Looks like we found the problem. The intake manifold gasket was leaking by the thermostat housing. One of the bolts came out milky, and the guy said that there was hardly any gasket left in this area. Hopefully that's the entire source of the problem.

Posted by: VETTKLR

Well, that's good he found your problem. Do you not check the motor before you head out on the water that often?

Posted by: Slow Nova

Quote:

Originally Posted by VETTKLR


	Well, that's good he found your problem. Do you not check the motor before you head out on the water that often?

I've had the boat only 4 months, and have taken it out only 5 times. I wasn't having any problems with oil or coolant leaking until this last time.

Posted by: VETTKLR

That's strange that it took so long for a gasket leak to surface, but I've seen stranger things happen to a motor.

My advice is to lay some fatass RTV beads down the front and back of the block for the intake to sit. I don't trust those cork gaskets for shit. Might as well smear some RTV on the thermostat gaskets as well.

Above all, happy boating!

I've got a Maxum 2100-SC with a Mercruiser 350 in it now...fuggin gas hog is a blast! I just hit all the water drains to winterize that badboy a few days ago. Boating season in the TX Panhandle is usually around May through early October.

Posted by: Slow Nova

Quote:

Originally Posted by VETTKLR


	That's strange that it took so long for a gasket leak to surface, but I've seen stranger things happen to a motor. My advice is to lay some fatass RTV beads down the front and back of the block for the intake to sit. I don't trust those cork gaskets for shit. Might as well smear some RTV on the thermostat gaskets as well. Above all, happy boating! I've got a Maxum 2100-SC with a Mercruiser 350 in it now...fuggin gas hog is a blast! I just hit all the water drains to winterize that badboy a few days ago. Boating season in the TX Panhandle is usually around May through early October.

Thanks for the advice.

Around here, there's no such thing as winterizing, and "boating season" is all year round.

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