SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: HubrisHCC on May 29, 2021, 06:37:36 pm

Title: Need Help with a milkshake
Post by: HubrisHCC on May 29, 2021, 06:37:36 pm
I could really use some advice.   I have found a valvetrain covered in mayo,  I am not exactly sure where to put my attention first.  I originally assumed I have a blown head gasket,  but as I began tearing down the engine I realized this could happen for multiple reasons.  does anyone happen to know where I should focus my attention first, before yanking the heads?  Recently I have noticed a fluctuation in oil pressure. The oil level was low but the dip stick was not creamy. 
Title: Re: Need Help with a milkshake
Post by: Flusher on May 29, 2021, 08:16:55 pm
Always start with the cheapest/easiest things first.

Start with checking spark plugs.  Pull the plugs and let us know what you find.  Keep the plugs in order so you know what cylinders might need attention.

Follow that with a compression test.  Maybe there is a simple fix.  At least you will know what direction to go.

I need to ask, what makes you believe it might be a head gasket?  How was it running before the incident?  How is it running now?  Anything else you could tell us about what might have caused this?

On a humorous note, the most common answers that I get are, "It was running great!  The best it's ever run!  This just happened." and, "I let the wife drive it..."
Title: Re: Need Help with a milkshake
Post by: Flusher on May 29, 2021, 08:26:46 pm


Recently I have noticed a fluctuation in oil pressure. The oil level was low but the dip stick was not creamy.

How much oil does the pan hold?  How low was it?  Please describe "fluctuation in oil pressure" and when does this occur?
Title: Re: Need Help with a milkshake
Post by: TrollerDave on May 29, 2021, 11:31:57 pm
I could really use some advice.   I have found a valvetrain covered in mayo,  I am not exactly sure where to put my attention first.  I originally assumed I have a blown head gasket,  but as I began tearing down the engine I realized this could happen for multiple reasons.  does anyone happen to know where I should focus my attention first, before yanking the heads?  Recently I have noticed a fluctuation in oil pressure. The oil level was low but the dip stick was not creamy.
Why did you open the valve covers? Sometimes you can get condensation in the rocker arm area and that is causes the milkshake there and not on the dipstick.


Sent from my iPhone using SoCal Jet Boats mobile app (http://r.tapatalk.com/byo?rid=201)
Title: Re: Need Help with a milkshake
Post by: HubrisHCC on May 30, 2021, 06:59:05 am
So jumping straight to the headgasket is more of a result with automotive experience and not marine.  The boat for the most part has been running well.  The last trip out I noticed an intermittent exhaust pop with 8/10s or more throttle and under load.  This was only a few instances for the weekend and I figured it was plugs, wires, cap/rotor etc.   Then one morning on startup I had a large puff of smoke.  I'm pretty sure it was oil smoke and not steam...    This was unusual but only happened that one time.  As for the oil pressure fluctuation,  the pressure will run around 60psi and then begin to drop off to around 20psi as the engine is constantly running.  I thought this issue was from oil sloshing in rougher water and foaming up as it hit the crank.  This whole process would take 10 to 15 mins underway and pressure would be back up after a couple min at idle.   This is what led me to check the oil level.  The boat has been slipped overnight for these last trips to the lake, and the weather in Havasu has been cooler.

The plugs look the worst I have ever seen them.  #1 has some big time corrosion and that entire bank looks like its had some moisture introduced into the cylinders.  I do, and have always run flappers on the exhaust.
Title: Re: Need Help with a milkshake
Post by: HubrisHCC on May 30, 2021, 07:02:57 am
Oh and the oil was about a quart low,  so as I looked through the hole in the valve cover before I added oil I noticed the cream.
Title: Re: Need Help with a milkshake
Post by: Flusher on May 30, 2021, 05:12:19 pm
I do not believe that running a quart low would cause any issues.  I do believe that lowering the oil level 1-quart helps prevent aeration, getting the oil away from the rotating assembly.
Title: Re: Need Help with a milkshake
Post by: Flusher on May 30, 2021, 05:16:16 pm
Were you able to run a compression test?  Are you proceeding with pulling the heads?  How do the intake gaskets look?
Title: Re: Need Help with a milkshake
Post by: HubrisHCC on June 02, 2021, 08:20:58 pm
So I haven't had a chance to check compression. I did change the oil.  I didn't find any moister in the filter or the rest of the oil so I changed the plugs and figured I'd give it a quick run on the lake.   It got milky pretty quickly.   I ran it to get the temps up a bit. I then noticed it had a creamy film all the way up the breather tube.  Could a bad PCV cause condensation to build? Either that or excessive crankcase pressure causing oily cream to climb the breather tube up towards the air filter.

Sent from my SM-G960U using SoCal Jet Boats mobile app (http://r.tapatalk.com/byo?rid=201)

Title: Re: Need Help with a milkshake
Post by: HubrisHCC on June 02, 2021, 10:20:07 pm
So I got the compression numbers
I'm really not sure what to make of it, other than #1 and #3 probably have some  issues.

#1 - 70
#3 - 80
#5 - 117
#7 - 130

#2 - 125
#4 - 110
#6 - 118
#8 - 140

Sent from my SM-G960U using SoCal Jet Boats mobile app (http://r.tapatalk.com/byo?rid=201)

Title: Re: Need Help with a milkshake
Post by: GT Jets on June 05, 2021, 09:56:34 pm
I would do a leak down test before pulling it apart.

Sounds like it's hurt.

Sent from my IN2017 using SoCal Jet Boats mobile app (http://r.tapatalk.com/byo?rid=201)

Title: Re: Need Help with a milkshake
Post by: GT Jets on June 05, 2021, 10:29:53 pm
So I haven't had a chance to check compression. I did change the oil.  I didn't find any moister in the filter or the rest of the oil so I changed the plugs and figured I'd give it a quick run on the lake.   It got milky pretty quickly.   I ran it to get the temps up a bit. I then noticed it had a creamy film all the way up the breather tube.  Could a bad PCV cause condensation to build? Either that or excessive crankcase pressure causing oily cream to climb the breather tube up towards the air filter.

Sent from my SM-G960U using SoCal Jet Boats mobile app (http://r.tapatalk.com/byo?rid=201)
I would pull the 1,3,5,7 exhaust manifold and have a look see.... Could be something as simple as a failed riser gasket or crack/hole in the exhaust ports near cylinder 1 and 3.

Good luck.

Sent from my IN2017 using SoCal Jet Boats mobile app (http://r.tapatalk.com/byo?rid=201)

Title: Re: Need Help with a milkshake
Post by: HubrisHCC on June 06, 2021, 06:12:14 am
I was thinking the same thing.  I pulled the risers apart yesterday, found a crack in the gasket on the 2,4,6,8 side.  On the other side, I couldn't get everything apart clean enough to give it a proper inspection.  I'm going to replace the riser gaskets, change the oil once more, put a new PCV in there for good measure, and take it out and see.
Title: Re: Need Help with a milkshake
Post by: GT Jets on June 06, 2021, 08:23:13 am
I was thinking the same thing.  I pulled the risers apart yesterday, found a crack in the gasket on the 2,4,6,8 side.  On the other side, I couldn't get everything apart clean enough to give it a proper inspection.  I'm going to replace the riser gaskets, change the oil once more, put a new PCV in there for good measure, and take it out and see.
I think I would do a leak down test before it's run again.

You might find you have a valve issue  and if it worsens, could take the engine out all together.

Also for safe measure, I would pressure test the cooling side with some air pressure, just plug the incoming and outgoing water lines and put 20psi of air to it. I think I would drain the block completely first.

If for no other reason than piece of mind.

Good luck brother.

Sent from my IN2017 using SoCal Jet Boats mobile app (http://r.tapatalk.com/byo?rid=201)

Title: Re: Need Help with a milkshake
Post by: HubrisHCC on June 06, 2021, 08:38:06 am
I can't argue with that logic.  I think im gonna take that route.  It'll take some time but worth it in the long run.  Thanks GT for setting me straight.

Sent from my SM-G960U using SoCal Jet Boats mobile app (http://r.tapatalk.com/byo?rid=201)

SMFPacks CMS 1.0.3 © 2022