Blown Mercruiser 3.0 Head Gasket

In this video I find out my head gasket did in fact blow again on my Mercruiser 3.0. I skip the tear down and reassembly in this video and share a few reasons why I think it failed this time around, I also address some comments and concerns on my previous repair video. Head Gasket Part Number: 18-2946 made by Sierra International
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Aviation Permatex Buy here: amzn.to/3OPWCnD
For sanding I used 80 grit sand paper to do all the heavy sanding and finished of the sanding with 120 grit.
To watch my previous headgasket videos
Tear down video: • Mercruiser 3.0 Head Ga...
and
Assembly video: • Mercruiser 3.0 Head Ga...
or
Our fun boating trip: • Lake Winnebago vacation
or
Boat Audio on the cheap: • Affordable Boat Audio
00:00 Intro
04:54 skip explaining myself
05:22 confirmed head gasket
06:06 Sanding the head
09:00 sanding the block
11:30 Head gasket talk
12:44 Aviation Permatex
Outro song: No More By Tomh can be found at soundcloud.com under creative commons license: creativecommons.org/licenses/... The song has been shortened to best fit this video
Thanks for watching, please consider subscribing!

[@plainandsimple1]

Hey dale, buy DYKEM Layout Fluid. Spray that on the head. then start sanding. once it's all gone, then you're basically level. also if you get a longer piece of wood thats longer than the head or block, that usually works better and ensures you arent sanding in one spot.

[@sasakuz8070]

Yes you are rite,but if you dont take down side cover of lifters than u cant do that

[@falconeaterf15]

In mechanic school, 30 years ago, we were taught to just use a light smear of engine oil on head gaskets. And torquing the bolts in the correct sequence, to the correct value, is also very important.

[@mramazing9000]

My old boss sweared by that aviation permatex

[@daleofalltrades]

So does my father, we'll see how it works. I couldn't have heard it worse than it already was!

[@aNuthaRedneck]

​@@daleofalltradeshow did it work? I'm installing my 3rd headgasket.

[@johnwagner9192]

Thinking about doing the same thing on the manifold. I took it off because of a suspected leak and the surface is a little rough and not totally flat.

[@rickobrien2797]

Good

[@ManuelCastillo-pr6sl]

Hey Dale! thanks to you I opened my engine, thinking I hada broken gasket, .. I didnt lol, but I think water was getting to engine as gasket was very slim.. I used a glass with sandpaper to resurface block uppper one of course..

[@daleofalltrades]

You welcome... I think? Hope it helped you out. Never a bad idea to investigate ether way! 👍

[@mad5773]

Same thing happened to me. Your previous video helped me with this repair. There are a few extra precautions I used to hopefully prevent this from happening again. 1. Use thread sealant on clean or new head bolts 2. Replace the rocker arm nuts $6.00 3. Re-Torque the head bolts after initial startup Hopefully it will hold together this time!

[@mramazing9000]

Subscribed , seems like you have my luck

[@daleofalltrades]

Thanks for the subscription! Luck is definitely been down lately.

[@davetrepse83]

Last year I bought a bayliner with 3.0 merc. And yes , its running funny on idle too....im gonna do a compression test and im sure its the damn gasket...

[@daleofalltrades]

Another easy was is pull the spark plug wires off and reinstall one at a time. If it doesn't run any different when ones removed it's a good indicator of a dead cylinder

[@davetrepse83]

@@daleofalltrades yes i will do that as soon as winter is finished because its in the field behind , in the snow ! Hahahha i will guve you feedback ...

[@Cruisingthesouth]

Permatex I use that s&@%#t on everything LOL!

[@alexoleag4508]

Hi Dale, our litter boat Maxum sr3 1800 has the same same same problem with gasket, 3.0 L any tips to buy gasket, maybe some webside, thanks, have a good time.

[@daleofalltrades]

So far mine is holding together this time with the steps used in this video. I have links in the descriptions in all my videos to the parts I used.

[@jaretbevan4364]

Did you also apply the permatex to the head before putting it back together as well?

[@daleofalltrades]

Not needed as it was on the block and then the other side of the gasket. But if you wanted to you could put it on the block and then the head and leave the gasket dry.... Ether way you want it on both side of the gasket. Hope that helped.

[@michaelbrewer1474]

When you was running on two cylenders was you going about 10 mph trying to get back to the dock? The reason I'm asking is because I'm looking at a boat that has a volvo 3.0 with a blown head gasket. Thank you for the great videos!!

[@daleofalltrades]

Yea about 10mph definitely couldn't get on plane. Could hear it wasn't running right. Volvo 3.0 is basically the same block

[@bill7229]

Hi Dale, Getting ready to do my 3.0 also. Your boat still holding together? I read that if the timing is too advanced, it can blow the gasket as there’s no place for the exhaust gas to go so it blows the gasket.

[@daleofalltrades]

It's running great yet issue free. I have since checked the timing a little after posting this video and it was right in spec in accordance to the book.

[@falconeaterf15]

Ahhhh………the joys of boating.

[@arnedemos]

Exactly the same with our boat. 3.0 mercruiser Watched your super clear video en replaced it. How was the extra “glue” holding up? I have to do it again. Damaged my new gasket and the water is squirting out.

[@daleofalltrades]

2 yrs still strong

[@arnedemos]

@@daleofalltrades I want to thank you from the Netherlands 😁👍

[@daleofalltrades]

@@arnedemos you are very welcome! Glad it helped

[@neverclevernorwitty7821]

Oooo. Sorry to hear that. When I did this job, my #2, #3 were lower running about half compression, if I recall from your last video, you had zero compression on #2, #3, right? Yah, it probably needs to be machined. Also if your theory is right that you have warpage out of spec, I thought I remember reading the composite gaskets are more forgiving of any variations, but a metal gasket are even more strict. I hope it works for you, what's your compression after?

[@daleofalltrades]

Compression after is always around 100 per cylinder, so over min spec. We'll see how it hold. Block isn't worth too much work in it's condition.

[@neverclevernorwitty7821]

​@@daleofalltrades Yeah, after my job all mine were 120-130, hope yours holds for the season!

[@yourselfdotcom]

Want my horror story. I discovered your video due to having spark plug #4 seperate leaving the lower half in the head. Now I get to remove the head and get it fixed. Oh its a customers boat and was being winterized. Last plug to fog the hole and bang the plug breaks. Shit happens buddy. Keep at it. Being stubborn pays off. 👍

[@Vegasman77704]

why wouldnt you use marking paint to find surface contact?

[@daleofalltrades]

You definitely can.

[@samhart6549]

Did I miss the "how to remove the alignment stubs from the block"?

[@daleofalltrades]

They pull out pretty easy with a vise grip. I may have skipped over that minor detail in the video or it got edited out. This is the 3rd video in a series I did also.

[@jakethruman8609]

I'm new to working on boats. During this process I forgot to drain the head before I pulled it off and filled the cylinders with water. I dried them out and sprayed them down with WD40 rightaway. Will this mistake hurt anything? Not sure if water can seep down around the pistons.

[@daleofalltrades]

You should be ok, especially since you sprayed them down with Wd40, just be sure all the water is gone. And change the engine oil after it's all back together. It may smoke white a little bit on 1st start up.

[@jakethruman8609]

Have you had a chance to run your boat with the Permatex 3? I am in the process of doing the same thing. I used a really thin layer but it still squeezed some out around the edges of the head when I torqued it down. I'm wondering if it might have squeezed some into the cylinders.

[@daleofalltrades]

Yup! I've had it out twice now and it's running great. Yes it's going to squeeze out everywhere. I'm sure some did get on the cylinders on mine. Shouldn't affect it. I put it on pretty generous. The cylinders get hot during combustion. Pretty sure it'll burn off after a few hours... Anyway no issues here so far. I plan on trying to make a short lakeday video yet. Just so busy.

[@laithalmarayati138]

Hey, thank you for this video, after seeing your video will work on my 3.0 mercruiser engine that has water in engine. I’ve questions about the process 1. Sandpaper only grade 80 2. Can I send the just the head to the shop? Hope you can see my comment. Thank you very much.

[@daleofalltrades]

Yes you can send just the head to a shop. I sanded both and didn't send out. It's running great this year so far holding strong. Make sure you use that aviation permatex. Yes I used 80 grit. You can use 100 or finer. It will take longer to remove material though. 80 seemed to be the magic number. If you want more detail on the tear down and reassembly I have two videos on that also.

[@laithalmarayati138]

@@daleofalltrades it’s my second days watching your videos to study and understand the process you did amazing job, Definitely will use this liquid and will keep you posted also I want to thank you for your swift response. Did you mind if I ask more questions when I start working on? Thank you and God bless you.

[@daleofalltrades]

@@laithalmarayati138 you are welcome. I truly want my channel to help people and motivate others to try there hand at projects themselves. Study the videos as much as you can most of the answers you need should be in them. I'll answer any questions I can.

[@laithalmarayati138]

@@daleofalltrades hey sir, wish I can send you some pictures for the head to get advice from you.

[@daleofalltrades]

[e-mail] is my KZbin contact email. Feel free to send them there

[@81mrlz]

Hi I'm curious how is the engine doing today?

[@daleofalltrades]

It held up and is now winterized for storage.will be running it next year until it needs any other work.

[@user-hv8ug2bz5j]

Hey buddy I have a 3.0 mercuries it started to turn over but wouldn't start then it went to just a clicking noise then it went to nothing no power to nother blower lights nother when I turn the key is there a main fuse somewhere or something I should be looking for thanks Doug

[@daleofalltrades]

Are you sure the battery just isn't dead, or you have a poor connection at the battery, or the battery cables are bad? If all of that checks out I do believe there is a 50 amp main fuse near the starter

[@user-hv8ug2bz5j]

@@daleofalltrades thank you I will check that out I believe there's a 90 amp fuse on the starter as well I'll check that next thanks again I'll keep you updated

[@jkrlozjherdez2924]

I have the same issue with my boat, but when you realized that it overheated, did your oil turn milky? i removed the head gasket from mine as well, and it isn't broken,m but has the same smudge in the middle as yours. even though it isn't broken, the head gasket has damage right?

[@daleofalltrades]

Yes the oil turned milky and yes if the head gasket is smudged/burnt it's damaged. Either way once you take a head off you can't reuse the gasket.

[@jkrlozjherdez2924]

I have a doubt, is it possible that the crack in the block has caused some internal damage? Today when disassembling the engine I discovered that they tried to repair the crack with flex core welding and they did such a bad job that I could remove the welding with my fingers so I decided to repair it myself in the best way and discovered that the manifold also had a crack and I also repaired it now everything seems to look better than before I hope it works but I have the doubt that the crack may be invisible what do you think ? Thanks

[@daleofalltrades]

@jkrlozj Herdez it's kinda hard to say. Mine has 2 cracks in it and has been previously repaired. There are a lot of boats with these engines cracked running around. Only way to find out is slap it back together and see if it's fixed.... Won't be out much just a gasket and some time.

[@jkrlozjherdez2924]

@@daleofalltrades Update... well after all the job is done finally today I started the engine and everything looks good while I test it in my house but when I put the boat in the lake after 30 minutes I stopped it to check the oil and surprise! milky oil is there Again, the only way to check what happens is to tear down again and check the head gasket fon any damage, otherwise, the block has an internal crack, in that case, I will sell it for parts... what do you think? Cheers!

[@daleofalltrades]

You could always do a compression test that way you don't have to tear it back down. If compression is low on more than one cylinder it's most likely the head gasket. Otherwise everything you said is correct. Sounds to me like an internal crack, 30 minutes isn't very long to blow another head gasket when mine went the second time it was hours of use

[@christianconner5095]

How is the motor holding up so far?

[@daleofalltrades]

So far so good. Unfortunately I was having a hard time putting a good update lake day video together. But if you want to watch I give a status update in this video and show it running strong 😃 kzbin.info/www/bejne/nKPPgnR6arp2ers

[@MrJhnbapst3]

After 2 years how has this held up?

[@daleofalltrades]

Still running strong 💪

[@MrCollins44]

I build cylinder heads for a living and live in N.Alabama,it's 40.00 to surface a head here.

[@daleofalltrades]

I know the price for a resurface itself is not that bad. However does that price include tearing the cylinder head down removing all the valves, magnaflux, and a pressure check on the head? Also my concern was wait time. As I wanted to get this thing back on the water as soon as possible. I will add it still running strong, and I plan on putting a new engine in anyways so I wanted to sink as little money in as possible That's why I shared this video. Hence the reason I call it a Band-Aid fix multiple times and state that it is not the proper way of doing things. I now have a replacement engine sitting in my garage that I am going to slowly put together with all new parts resurfaced the proper way etc. Thought I'd give you a little backstory there and the reasons why I did it thanks for watching!

[@MrCollins44]

@@daleofalltrades No,if I did all that for 40.00 I wouldn't be able to put gas in my boat.It's tough when you hear the river calling your name. Good luck and keep her floating.

[@aNuthaRedneck]

​@@MrCollins44I took my boat with the head off to a machine shop this morning. He resurfaced the head and checked my Block for warpage while i waited.. on the house. He definitely will be getting my business. 0$

[@MrCollins44]

@@aNuthaRedneck Hope you gave him something anyway.

[@aNuthaRedneck]

@@MrCollins44 I gave him the best thing a business can have... a new good customer. I just recently had him do a bore job for me a couple weeks ago.

[@sasakuz8070]

Hello can you help me pls.Can i put this manifold on this head.I just finsh head job and must change old manifold becouse it was cracked😢

[@daleofalltrades]

I'm sorry your question isn't making sense to me. Are you asking if you can use the cracked manifold? No it will need to be replaced with the correct manifold

[@sasakuz8070]

Hi.I have doubt what manifold to put on my mercruiser 3.0 1996.Where i can send you foto to show you what i mean.

[@sasakuz8070]

​@@daleofalltradesSry for mis undestanding.Whan i write mesage i was thinking i can sent you photo here,but i cant😅

[@daleofalltrades]

@@sasakuz8070 your best bet is to got to mercury's website or a 3rd party parts website and enter the engine's serial number to be sure you get the correct parts

[@sasakuz8070]

Ok tnx.

[@Mrcaffinebean]

Good videos man, they were very helpful. Your local machine shop would probably surface that head for probably a couple hundred bucks. I’m told that normally the block doesn’t warp much if at all and it seems like you found the same. All that being said I would not be shocked if this repair lasts just fine. Sometimes things don’t need to be done perfectly to last a long time. Kudos for posting this, some people would be self conscious after redoing a repair on camera. But it happens to everyone!

[@daleofalltrades]

Thanks. I definitely don't want to hide anything. My hole goal is to help someone else going though the same issues.

[@2discoveredm788]

So as a mercuiser mechanic. We have learned that oem timing is a little on the dangerous side. Have seen the 3.0 blow head gaskets over and over. Different boats different ages. Turns out that mercruiser timing advance is almost too advanced. It leads to blowing head gaskets when set to factory specs. We do not set it too advanced anymore. One to two degrees retard, from what the engine calls for, will save the motors and eliminate head gasket issues

[@daleofalltrades]

Interesting. Good to know

[@aNuthaRedneck]

I'm reading several different specs for timing. So exactly what should the timing be set at for a 3.0?

[@2discoveredm788]

@@aNuthaRedneck alright this may sound controversial. But believe me its good info and wont come back to bite you. So the normal way is to jump the two white wires at the distributor then crank the motor. It will be in locked timing mode. Then with the timing light connected to cylinder 1 set the timing to 2°ATC. But scratch that lets do it the way that is safe on all the motors. Okay dont jump the two white wires at the distributor, just take and raise your engine rpm to 1000rpm, gets module in the distributor out of base timing, and set timing right at 0°while revved to 1000rpm. Not before TDC and Not after TDC. Your motor will love it and last with never needing timed again. And no blown head gasket if you do it like that. When idled back down after tightening the distributor bolt, just set the carb screw to idle where you want it in gear and done

[@aNuthaRedneck]

@@2discoveredm788 man I'm praying you're right. It's HOT here and I'm too damn old to keep messing with this motor.

[@2discoveredm788]

@aNuthaRedneck @aNuthaRedneck no please... 3 to 4 atdc is guaranteed to blow the gasket. So bring it closer to btdc But right at 0° is about as much as you want to bring it back. Not wanting it to hit btdc on a 3.0. It will loose power advancing timing gives more power but 3 to 4° atdc is killer timing, it will eventually lead to blown gaskets and scars on the cylinder walls others I talked to that set it at 3 to 4 always ends badly. and I don't jump timing wires to set it

[@BigDaddy-fq5mu]

Nobody gonna mention that cracked block?

[@daleofalltrades]

Bro did you not watch the 1st 3 minutes.... I talk about it 😂

[@daleofalltrades]

@2:39

[@BigDaddy-fq5mu]

@@daleofalltrades 0:35, sorry dude.

[@daleofalltrades]

@@BigDaddy-fq5mu right I said skip ahead. It's all good. I've just heard so much about my cracke block in previous videos.

[@rossbritton4008]

Take the head and have it milled/ Surfaced..What about all the Sanding Material that went into the block..?

[@daleofalltrades]

Still running strong with this fix. Definitely stated it wasn't the correct way. Most sanding material was caught by rags in the cylinders. "Band aid fix" I have a hole needle black sitting on an engine stand waiting for this one to go out. My block is also cracked (prev owner) so it's not worth the money