engine block for 470

[Todd Peterson]

I changed engine oil on my 1984 470 mercruiser 3.7 and the oil came out milky. I put new oil in and started it for 3 minutes and the oil came out milky again. What are the options and where can I get a rebuilt engine or just the block? I live in Minnesota.

 

[TilliamWe]

Re: engine block for 470

Do a search on here. That is a common issue and it's usually not a cracked block. It is usually a seal around the front of the camshaft or something like that. Very specific to that motor.

 

[Todd Peterson]

Re: engine block for 470

Thanks. The engine did overheat last fall before I put it away for the winter. I took the boat to the shop today and they were going to check the compression in the cylinders. What else can they check to see what the problem is before they just guess at the block being cracked?

 

[bhammer]

Re: engine block for 470

It won't be the cam shaft seals unless you just changed them and installed them in backwards. If you overheated it, I'll almost bet that it is the head / head gasket which is common for the overheat on this engine. Your tech should be able to pin point it with a compression and leakdown check.

 

[Todd Peterson]

Re: engine block for 470

Thanks. It went the shop yesterday and they are going to check the compression. I hope it is the head gasket. I do not want to look for a block or new engine.

What is a leakdown check. and what does it check for?

 

[bhammer]

Re: engine block for 470

My guess is that it is a head or the gasket. You can have it remaned for not a lot of money. For an explination of a leak down: http://www.carcraft.com/techarticles/116_0406_cylinder_leakdown_tester/index.html Good luck an dlet us know.

 

[Todd Peterson]

Re: engine block for 470

Thanks. I have not heard from the shop yet. I will keep all posted. Donations are welcome for the repair.

tp

 

[Todd Peterson]

Re: engine block for 470

The shop called today and they pressurized the cooling system and there were no leaks or the pressure did not decrease. The said that my stator flew apart and could not start the engine to conduct the compression test. They wanted me to put on the new stator or alternator kit before they could do the leak down test. I told they could remove the stator and just use a battery charger to start the engine and check the compression. They were able to check the compression and found that all 4 cylinders were all good. They are going to pull the head and look at the gasket. I have an aluminum block and it is not (should not be) cracked. I think it will be the head gasket.
Is there any thing else they should check or replace when they pull the HEAD?

tp

 

[bhammer]

Re: engine block for 470

Well, that is good news compared to what it could have been. Don't go back with the stator as it will cost more than the alternator conversion kit. It seems strange that it would come apart on them though...

Just have them do a good look over the head and if it has a crack, they will find it. You may get off lucky with just a head gasket.

 

[TilliamWe]

Re: engine block for 470

Okay, so you have good compression and no cooling system leak? So why are they removing the head? If it had a blown head gasket, wouldn't the compression be off on one cylinder? I fear that you are having a bunch of unnecessary work done. I know bhammer says it's not the camshaft seal, but almost every other post I read on here about antifreeze in the oil of a 470 is caused by that seal. Just a thought, maybe someone should check it out?

 

[bhammer]

Re: engine block for 470

Okay, so you have good compression and no cooling system leak? So why are they removing the head? If it had a blown head gasket, wouldn't the compression be off on one cylinder? I fear that you are having a bunch of unnecessary work done. I know bhammer says it's not the camshaft seal, but almost every other post I read on here about antifreeze in the oil of a 470 is caused by that seal. Just a thought, maybe someone should check it out?

TilliamWe, that is a good question, but, I have seen a head gasket leak coolant into the oil without affecting compressions. Here is a link that explains the camshaft seal problem as well. http://www.sterndriveshop.com/470information/470coolantleakrepair.html I have only seen one time where the seals have allowed coolant to leak past into the engine oil. that was becasue an owner had though the timimng cover had a leak and he plugged the weep hole, which is what is designed to keep the coolant from getting into the oil.

They do leak all the time and is a big problem on the older engines, just not leaking into the oil though.

 

[TilliamWe]

Re: engine block for 470

Ok, hammer, I accept your explanation.

 

[bruceb58]

Re: engine block for 470

It is possible that the milky oil is caused by a bad exhaust manifold/riser. When the oil gets milky, does the level of the oil change much? Is this boat run in salt water? What do the plugs look like? Are they rusty?

 

[Todd Peterson]

Re: engine block for 470

I did not notice the oil level change when I changed oil and started the engine.
The boat runs in fresh water only, I am land locked in Minnesota.
I changed the plugs this spring and they looked like they have not been changed for a long time. This is my second year with the 1984 Baretta. It has been an expensive project.

I saw the parts today at the shop. I believe they took off the exhaust manifold already. I will check with them tomorrow.

I will have them take out the magnets on the flywheel and go with the alternator upgrade kit. They want $900.00 for the kit and 1 hour for labor. I have seen it for $350.00 on the internet. Where can I find this cheaper. I am looking for a salvage yard in Minnesota to get the bracket. I can buy the alternator and harness and install my self.
Does anyone know where I can get this in MN?

 

[jerryjerry05]

Re: engine block for 470

Do the alternator yourself. Are you loosing antifreeze??? .If so the problem is probably at the end of the camshaft.It has 2 seals there and the inner probably went bad. Is you antifreeze getting wattery?If so your heat exchanger could have a crecked cooling rod.If not there then the riser could be bad. Remove the manifold plug all misc hoses and run a hose to it and see if there is water comming out anywhere but the exhaust.
Front of the motor bottom left on the waterpump housing is a small hole.Make sure it aint plugged.Jerry

 

[Todd Peterson]

Re: engine block for 470

Jerry,

I am not loosing antifreeze. What hole is in the front that I should check? What does it drain?

Still looking for a alternator kit!!!!

 

[Todd Peterson]

Re: engine block for 470

Well boys and girls I have just been ****ed.

I picked up my boat from the local marina in Mound MN (lots marinas to choose from in the lake Minnetonka, MN area so I do not slam the marina).

I had a milk shake type of oil this spring. Last fall I did have an over heat and all seamed fine. After the overheat they winterized the boat and I stored it covered, out side in MN weather.

When I started it this spring, the oil was the milk shake type. Even after two oil changes that I did. Now they told me to put back the front motor mount it would take 1,200.00. I said to get the bill ready for $2,700.00. So I have this money in this boat and the engine runs great. Boat framing is a bit suspect.

What I need to know if any one wants to donate money to me for repairs. My wife said she did not want to buy a new floor and seats. So it is prime season for boats in MN and I will take the boat back to the marina and have them winterize it and store it for the winter......in July.

Please help

 

[bomar76]

Re: engine block for 470

What I need to know if any one wants to donate money to me for repairs...........
Please help

That takes some gall.....

How about some free advice instead of a handout.....

Don't have hobbies you can't afford.

 

[erikgreen]

Re: engine block for 470

Yeah, most folks here don't have a ton of cash available (we're all boat owners) and even if we did, you're not entitled to any of it just because you have a junky boat.

Do the work yourself and we'll supply knowledge and support, it'll be cheaper and you'll have a boat to be proud of.

Alternatively, part out the boat you have and buy a $500 used boat that runs, and enjoy the rest of the season while you save up for a better boat for next year.

If it's really important to you, talk with your wife about buying a new boat and making payments.. once she sees the price of a new one she might be more likely to work out a way to get this one fixed.

Erik

 

[bruceb58]

Re: engine block for 470

I think the guy was just venting.