Cracked Block ?

[Gbay73]

I was having an issue earlier with timing, dwell etc. on a Volvo AQ130C. Was directed to set dwell and check compression before attempting timing. Well...
when I was checking compression, I found water in the #1 cylinder.( prob. about 125ml.) There is a milky residue on the top of the valve cover directly above #1 Cylinder and no noticable water in the oil pan or rise in oil level.
Any thoughts....
Cracked block?
Bad head gasket?
Exhaust issue?

 

[rbh]

Re: Cracked Block ?

I would start with the exhaust first as you have water in the cylinder, the milky crud under your valve cover could be a combination of a few thing.
condinsation, water entered through the top hole on your valve cover etc
when you slow down does your swell spill over onto the motor?
just a couple of thoughts
rob

 

[Gbay73]

Re: Cracked Block ?

I do not think it is an exhaust issue anymore.
The results of my compression test are:
Cyl.#1 - 170-180lbs
Cyl.#2 - 0lbs(Unreadable)
Cyl.#3 - 155-165lbs
Cyl.#4 - 170-180lbs
I am good with my hands, I am no mechanic though, but this seems really bad to me.

 

[rs2k]

Re: Cracked Block ?

The head is going to have to come off. You may have a burned of stuck valve, cracked piston, broken piston rings, cracked block, cracked head, or blown head gasket. In any case the head needs to come off.

 

[rbh]

Re: Cracked Block ?

yes I would certainly go with pulling the head and looking at the valves on number 2 cylinder. hopefully you can get away with a valve job, but check the guides for wear.
rob

 

[rs2k]

Re: Cracked Block ?

Did the engine ever hydro lock?

 

[Gbay73]

Re: Cracked Block ?

Well I am in luck.
I pulled the head off and.....
The head gasket was pooched at the #1Cyl. and
the intake valve for the #2Cyl. has a hole in it. Given what else could have been wrong I guess I got away pretty lucky!!

Now does anyone have the torque specs for the head bolts and the manifold bolts?

Thanx.

 

[rs2k]

Re: Cracked Block ?

The intake valve had a hole in it?? It's usually the exhaust valves that goes kaput.

What did your spark plugs look like? When was the last time you replaced the water intake impeller? What does the thermostat look like?

I don't know anything about the AQ130C, but a quick search found this: http://www.marineengine.com/discus/messages/12487/7701.shtml

It would be wise to verify that with a manual. You also need to find the correct torque pattern or you'll pooch the head gasket again.

 

[Gbay73]

Re: Cracked Block ?

Yeah, I too thought it to be a little strange to have the intake valve pooched and not the exhaust. All that I can imagine is that there must have been some sort of debris fused to either the valve, or the valve seat, and the "blow-by", over time burned it away.

Thanx for the torque values but yes I will also have to find the correct sequence.

 

[rs2k]

Re: Cracked Block ?

Can you post a picture of the valve? Someone might be able to tell you waht caused it by looking at it.