what does this mean?

[302mustang]

I just put my motor back together. (had a bad head gasket). I ran the boat for approx 2 hours and on my way back into port i here this pooof. My rpms drop considerably.

I pull the plugs today and put a compression tester to the cylinders... They all pump up but drop rapidly to zero. None of them hold any pressure. Also all the plugs are removed from the other holes and I see water blowing out of the holes.

This sounds like my head gasket. I thought I tightened all the bolts to spec. Am I correct in my assumptions and anyone have a clue why this happened? Or what caused this? Did i do more damage?

Thanks

 

[FreeBeeTony]

Re: what does this mean?

Is it a GM engine? If so, did you seal the threads on the head bolts? They pass into the cooling passages............

 

[bruceb58]

Re: what does this mean?

Was the head flat...not warped? What caused your head gasket to fail the first time...overheat?

 

[302mustang]

Re: what does this mean?

It is a GM version. The manual didn't say anything about sealing the bolts.

The problem for the bad gasket was an over heat. I've had the head machined and gone through.

What am i looking at here? Do i need to do a tear down again? Or can i just remove the bolts one at a time and seal them? Is this normal and did i cause more damage?

 

[FreeBeeTony]

Re: what does this mean?

what engine is it?

 

[302mustang]

Re: what does this mean?

3.0 gs. Volvo penta. 4cyl.

 

[Don S]

Re: what does this mean?

I pull the plugs today and put a compression tester to the cylinders... They all pump up but drop rapidly to zero.

If the pressure on your gauge drops, than means there is a problem with your gauge, not your engine.
Cylinders DO NOT and WILL NOT hold pressure during a compression test. never have, never will

 

[jdtower23]

Re: what does this mean?

Just had this problem with the compression gauge.....it's most likely a valve sticking in the hose....I just oiled the valve and worked it a couple of times and it worked again...

 

[302mustang]

Re: what does this mean?

what about seeing water flying out the spark plug holes when i crank the motor over? I know somthing is wrong because my rpms dropped while coming back into port.

could i be lucky as to think it's only the head bolts that need retightening?


Thanks,

 

[Haut Medoc]

Re: what does this mean?

Well, do what was suggested with the head bolts....
Was there water in all cylinders or just the side you worked on?.....
How old are the mans/risers?.....​

 

[Nova II 260]

Re: what does this mean?

The riser manifold, head and head gasket are the only things common to all cylinders with water available. If you warped the head when you overheated you'll need to have it surfaced and start over. Aluminium heads warp often when overheated.

 

[QC]

Re: what does this mean?

Whoa, one head and it's iron . . . 3.0 Just saw this getting derailed by his f'nscreename (inside joke 302) . . . He does not have a V8

 

[bruceb58]

Re: what does this mean?

When you put on the head, did you tighten them with a torque wrench and in the sequence recommended in the manual?

 

[302mustang]

Re: what does this mean?

yep head was resurfaced when i overheated it, and it is cast iron not AL. He said it was off a bit but did it anyway for me.

yep tightened the bolts to spec and in proper sequence. I'm going to pick up some sealer and see if she'll even fire up.

I really don't want to yank this head off again, i'm hoping it's that simple.

Also could this of been cause by me having the valves not set right? Because if i can remember correctly it think after i heard the noise and the sudden loss of power, It sounded as if the exhaust was louder (from the engine compartment) and sounded like i heard some ticking.

would this cause this same issue?

thanks again,


P.S - (and off topic) Yeah yeah, i'm a stang owner and stang fan. My wife is hounding me to sell it since the purchase of this "broken" boat. I'd be cool to put this motor in the boat, but don't think the stuff would line up. LOL.

 

[MercMonster]

Re: what does this mean?

It is a GM version. The manual didn't say anything about sealing the bolts.

Mercury Service Manual - C-90-71707 - Volume 1 - Section 5 - Cylinder Head Assemblies - Installation:

3. Coat threads of cylinder head bolts with Perfect Seal (C-92-34227) and install finger tight.

Do you have the OEM manual?

 

[302mustang]

Re: what does this mean?

no. I have the chiltons version, or whatever it is for boats. And i did finally read it instead of looking at the pictures and it says to coat the bolts with permatex. Which i'm doing right now. I'm also testing the torque settings to see if they are correct. I will try to get her running tonight and post a reply.

I find it hard to believe that all this problem is caused because of bolt sealant. Is it really that important? (not trying to be sarcastic or unthankful, it just sounds "off".)

And really thanks for all the responses, again I know what forum to come to with my problems, you guys are great and should get paid for this.