Antifreeze container empty in Mercruiser 470

copierkat

Seaman Apprentice
Joined
Nov 29, 2012
Messages
36
Hi all. I recently purchased a 83 Celebrity boat with Mercruiser I/O 470. I have not yet started it because it is still below freezing here in MN at night. I put in new plugs, and checked the anti-freeze container and it was empty. I looked in the oil filler in the valve cover and there appeared to be a small puddle of green anti-freeze in there. It was hard to tell for sure if it was oil or anti-freeze. When I pulled the oil dipstick, it had fresh clean oil on it, not milkshake looking at all. Should I do a pressure check? What do I have to purchase for the pressure check? Am I screwed? Thanks for any help! Dave
 

stonyloam

Vice Admiral
Joined
Mar 13, 2009
Messages
5,827
Re: Antifreeze container empty in Mercruiser 470

You can borrow a compression tester and A cooling system pressure tester from your local Autozone for free. I would recommend doing both a compression test on the cylinders and the cooling system pressure check. Good luck.
 

WIMUSKY

Moderator
Staff member
Joined
Sep 26, 2009
Messages
19,789
Re: Antifreeze container empty in Mercruiser 470

When you pulled the old plugs did any of them look "washed"? Or, did they all look pretty much the same?
 

copierkat

Seaman Apprentice
Joined
Nov 29, 2012
Messages
36
Re: Antifreeze container empty in Mercruiser 470

There is one plug that looks cleaner than the others. It is the one closest to the front of boat. See pics. Thanks
 

Attachments

  • 2013-04-01 18.44.57.jpg
    2013-04-01 18.44.57.jpg
    154.1 KB · Views: 1
  • 2013-04-01 18.57.38.jpg
    2013-04-01 18.57.38.jpg
    148 KB · Views: 1

stonyloam

Vice Admiral
Joined
Mar 13, 2009
Messages
5,827
Re: Antifreeze container empty in Mercruiser 470

Looks like you have coolant leaking into #4, very common problem. Probably time for a new head gasket. Do a compression check and look for low compression on #4. I think this is the manual for your 83: Boatinfo - Mercruiser Service Manual nr. 2 - 1974-1977 All Engines & Drives Doing a HG is not a huge job, just follow the manual EXACTLY and keep track of which holes the push rods come out of. Use only the OEM Mercruiser head gasket, aftermarket (sierra eg) gaskets are OK for the other parts (exhaust, intake etc.) Good luck.
 

copierkat

Seaman Apprentice
Joined
Nov 29, 2012
Messages
36
Re: Antifreeze container empty in Mercruiser 470

I am going to "borrow" a radiator pressure tester and compression tester for the cylinders from a local auto parts store and see if I have leaks. One of the spark plugs' insulators is clean which I think means antifreeze is leaking into that cylinder. That cylinder is closest to front of boat. (See pics above) Is this a high cost repair, or can I fix it easily. (Yeah, right!) Would it be wise to fill the antifreeze container and run with muffs? I have not started this boat since I bought it. (Let the headaches begin!!) Dave
 

copierkat

Seaman Apprentice
Joined
Nov 29, 2012
Messages
36
Re: Antifreeze container empty in Mercruiser 470

Thanks stonyloam. I was writing as you replied. I will check out the manual. Any problems starting this beast as it sits?
 

WIMUSKY

Moderator
Staff member
Joined
Sep 26, 2009
Messages
19,789
Re: Antifreeze container empty in Mercruiser 470

There is one plug that looks cleaner than the others. It is the one closest to the front of boat. See pics. Thanks

Yep, that's why I asked. As stony already stated, head gasket........ I had one replaced a few years ago, I forget what I was charged. I wouldn't run it until it's fixed. It's possible it may hydro lock and you may start bending a rod. Fluids don't compress very well.....
 

stonyloam

Vice Admiral
Joined
Mar 13, 2009
Messages
5,827
Re: Antifreeze container empty in Mercruiser 470

Is this a high cost repair, or can I fix it easily. (Yeah, right!) Would it be wise to fill the antifreeze container and run with muffs? I have not started this boat since I bought it. (Let the headaches begin!!) Dave

I would not run it too much, just enough to do the compression test. Not too expensive, mine cost about $500, but that included a valve job, replaced one valve and put in hardened exhaust valve seats. For tools you will need a good torque wrench and a standard socket set. The OEM Mercruiser head gasket runs about $80, and it is specifically designed for the 470, where the aftermarket gaskets are auto gaskets, and do not hold up as well. You will need intake, exhaust, side plate and engine waterpump gaskets (if you do the seals). I used Sierra, about $50 or so. While you are at it I would change the camshaft seals and crank oil seal, another $80 or so, will need to be done eventually so might as well do it now. The instructions call for perfect seal, but NAPA (Permatex) aviation sealant will work (and is cheaper). So maybe $250, maybe another $100 to have the head checked out by a machine shop (well worth it). The critical things are: do not mix up the lifter pushrods, follow the head torquing sequence exactly, and when done run it up to temp and retorque the head bolts. Best thing is you still have plenty of time to do it before warm weather. Good luck and welcome to the 470 club :facepalm:;)
 

copierkat

Seaman Apprentice
Joined
Nov 29, 2012
Messages
36
Re: Antifreeze container empty in Mercruiser 470

Thanks. You did not mention I would need an engine hoist, so I am assuming I can leave the engine in boat to do the job? Dave
 

matt167

Captain
Joined
Sep 27, 2012
Messages
3,630
Re: Antifreeze container empty in Mercruiser 470

If you are not the strongest person, you may need a hoist or help to pull the head. They use a single 460 Ford head, which is not light. Beyond that, there should be no reason to pull the motor
 

natemoore

Master Chief Petty Officer
Joined
Jun 13, 2009
Messages
844
Re: Antifreeze container empty in Mercruiser 470

Thanks. You did not mention I would need an engine hoist, so I am assuming I can leave the engine in boat to do the job? Dave

You don't need a hoist. You've got to be a pretty weak sister not to be able to lift the head off. All can be done with engine in boat.
 

copierkat

Seaman Apprentice
Joined
Nov 29, 2012
Messages
36
Re: Antifreeze container empty in Mercruiser 470

Sweet. I wasn't sure there would be enough room without pulling motor, but I will leave it in if it can be done that way.
 

artificialreef

Chief Petty Officer
Joined
Feb 21, 2009
Messages
504
Re: Antifreeze container empty in Mercruiser 470

Surprised noone said your screwed for buying a 470/3.7 without running it. I bought twins without running them, but did do a compression test. Please post your compression test results before you pull the head. That one plug may not have been firing.
 

natemoore

Master Chief Petty Officer
Joined
Jun 13, 2009
Messages
844
Re: Antifreeze container empty in Mercruiser 470

Surprised noone said your screwed for buying a 470/3.7 without running it. I bought twins without running them, but did do a compression test. Please post your compression test results before you pull the head. That one plug may not have been firing.

I was screwed when I bought a running 470.:grumpy: After two or three times out on the sound, I had to pull the engine and completely rebuild it and replace many parts. It's a good running engine now, though.
 
Top