anyone know the omc cobra 351 ford Help

[berks247]

Had the engine checked out after getting stuck on the water!! Water was spraying out at me when engine was running. Boat mechanic told me the oil cooler was shot but more impotantly the manifolds needed replacing; the engine was new/rebuilt in 2002; could the manifolds really be ready for replacing? He also said I had water in oil (milky), could that be from the manifolds being bad or possibly all the water that was spraying and coming back onto the engine and getting in somehow or would you suspect something bigger wrong? I'm brand new to boats and any input is greatly appreciated!!!!!!!!!!!

 

[berks247]

Re: help with OMC cobra 351 ford 5.8L

Re: help with OMC cobra 351 ford 5.8L

Had the engine checked out after getting stuck on the water!! Water was spraying out at me when engine was running. Boat mechanic told me the oil cooler was shot but more impotantly the manifolds needed replacing; the engine was new/rebuilt in 2002; could the manifolds really be ready for replacing? He also said I had water in oil (milky), could that be from the manifolds being bad or possibly all the water that was spraying and coming back onto the engine and getting in somehow or would you suspect something bigger wrong? I'm brand new to boats and any input is greatly appreciated!!!!! I don't know what other info you guys would need to help so just ask and I will try to answer the best to my knowledge.

 

[Bondo]

Re: anyone know the omc cobra 351 ford Help

or would you suspect something bigger wrong?

Ayuh,...... I'm guessing you Froze,+ Split the Block,+ Everything else.......

Who Winterized your boat for you,..??

 

[Don S]

Re: anyone know the omc cobra 351 ford Help

the engine was new/rebuilt in 2002; could the manifolds really be ready for replacing?

Did they replace the manifolds then? Just because it was a new engine doesn't mean it had new manifolds.

The only way to see where the water was spaying from it to look at it. No way can anyone say for sure where it was coming from without looking at it while it's spaying.

The milky oil could be from a cracked block from improper winterization (will also cause cracked oil coolers)

 

[berks247]

Re: anyone know the omc cobra 351 ford Help

I bought from my brother who lives in Minnesota; he had a boat mechanic who winterized it; it sat for 5 months before i brought it to florida; put the muffs on it in the yard and it fired right up; didn't notice any water leaks; sounded great (quiet and smooth)

The mechanic that I had look at it didn't mention he saw any cracks on the block; he said he couldn't really determine where water was getting in at; I had suggested possibly the water spray and he said that might be; or could water leak through the manifolds to the oil?

Do you think it would be in my best interest to see where the water is coming from before I get any repairs done; i have a feeling the fixing might never end until i get a new engine? Gosh i hope not?

 

[Haut Medoc]

Re: anyone know the omc cobra 351 ford Help

Pull the engine cover, start the engine & look.....
Water in your oil is bad....
It does freeze in Florida, does it not.....
Isolate the leak(s) quickly......​

 

[Haut Medoc]

Re: anyone know the omc cobra 351 ford Help

Welcome to iboats, BTW.....​

 

[Don S]

Re: anyone know the omc cobra 351 ford Help

I bought from my brother who lives in Minnesota; he had a boat mechanic who winterized it; it sat for 5 months before i brought it to florida;

So, you don't know what was done. How long did your brother own it? Did he always use that "Boat Mechanic"? How many times, did he do it properlly.
See where I am going with this?

The mechanic that I had look at it didn't mention he saw any cracks on the block;

Did you ask him to look? Most boats are designed where finding an external crack on a block may be impossible to see. Even then, if it's cracked internally, no one could see it.
It would also take a lot of running before it would effect how it ran.

Do you think it would be in my best interest to see where the water is coming from before I get any repairs done;

Yea, unless you have deep pockets. What are your mechanical skills, and do you have an oem service manual?

 

[berks247]

Re: anyone know the omc cobra 351 ford Help

just got boat to florida last week

brother owned it for 4 1/2 years always had the same mechanic work on it
same mechanic replaced lower unit and had to weld the top of the manifolds when brother first got the boat (couple months after he first bought)

my brother is not mechanically inclined nor am I; We are not sure what is required completely for winterization; just that you have to make sure all fluid is out of manifolds ect. to prevent cracking and such.

im going to go see the mechanic tomorrow- any important questions or anything to find out

no oem manual


Manifolds were not done with engine rebuild

 

[Don S]

Re: anyone know the omc cobra 351 ford Help

ANY, repeat, ANY time you have to do any welding on either the manifolds or the risers, they should be replaced, not repaired. In salt or brackish water, manifolds get replaced in the 5 to 10 year range as normal maintenance.
From the sounds of things you need ALL new manifolds and risers (aka elbows).
The fact that the engine is new in 2002 is not a factory oem job. OMC has been out of buisness for about 10 years. Volvo purchaced OMC Sterndrive in like 96 and stopped using Fords that year. So what you have as NEW in 2002 is hard to say at this point. Is it a marine engine? Does it suffer from reversion (water sucked into the cylinders) like the Chevy engines do? That is just part of the problem with your setup. It doesn't exist in real life.
There are no OMC, Volvo, or Mercruiser Ford engines now in use.
This will probably be a slow, information gathering, trying to figure things out, type post. So don't get all panicy to quick.

 

[rodbolt]

Re: anyone know the omc cobra 351 ford Help

ford withdrew from the marine market back about 1995, no fords got marinized after that.
the 351 had no water reversion isues and actually worked very well.
your water leak is something only you can see, but while its leaking take a picture and post it.
I just did a 7.4 volvo that was "winterized" however it was done improperly and the guy bought the boat with a busted block.
seems the marina in NJ forgot to drain the block BEFORE running the A/F mixture through it .
at least the manifolds and risers had A/F inthem

 

[berks247]

Re: anyone know the omc cobra 351 ford Help

thanks for all the support yall. Turns out someone replaced the distributor with an automobile dist.. as well.. Keeps getting better I'm thinking to get the leaks fixed, manifolds, oil cooler(power steering) and fresh oil and see what happens; and of course a MARINE dist.. Will try and get a photo after I get the main leaks fixed to see if any other leaks occur and post. Again appreciate the help!!!

 

[berks247]

Re: anyone know the omc cobra 351 ford Help

Yes it was an engine put in by a marina; if that is what you are asking; the marina provided the engine as well

 

[a70eliminator]

Re: anyone know the omc cobra 351 ford Help

I have a 351 Cobra OMC in my 90 Chaparral, it's all pretty much original unmolested and I may be able to help with some stuff but the problems your having now could be caused by just too many things. Mine is a smooth quiet running engine with gobs of torque.