Compression test results, how to swap headgaskets?

[BlueOvalStangGT]

No one was looking at my other thread anymore so I figured I would try another one. I did a compression test and got this

1-138
2-135
3-130
4-140
5-125
6-125
7-120
8-100

Thats a pretty good sign of a blown headgasket right? Im asking because I dont really have any other symptoms of a blown HG except for pressurizing coolant. Anyone have links or wanna explain how to swap HG's? Im ready to tackle this but a little scared since I never got to the internals of my engine before. Tips/Links/Advice/Anything would be great, thanks

 

[1105]

To swap a headgaset...

Remove intake, take off the fuel rail, might have to take out the distributer, unbolt your headers, take off the valve cover, take off the acc. bracket on the side that has the blown gasket, taking out spark plugs might be a wise idea, drain the coolant, take off the rockers, take out the pushrods, take out the head bolts and you're there..

Install, clean the block and head very good before you do anything, stick the gasket on, stick the head back on, torque it down properly, put the pushrods back in, put the rockers back on (dont know how to adjust pedistal mounts or else i'd tell you), valve cover, header, spark plugs, acc. bracket, intake

 

[BlueOvalStangGT]

What should I torque all these things to?

 

[nmcgrawj]

haynes manual or chiltons should say...

 

[1105]

thats the torque sequence... I torqued my top bolts to 80ftlb and the bottom to 75ftlb. I did them all 50 first, then 60, then 70, then 75 or 80 depending of they were on the top or bottom. Not sure what cast iron heads call for for how much you torque them down.

 

[BlueOvalStangGT]

To swap a headgaset...

, take off the acc. bracket on the side that has the blown gasket,

I was thinking, since im down there, I might as well replace both gaskets. Does this mean im taking out my blower AND my powersteering and stuff?

 

[wytstang]

yep they will have to be removed.

 

[1105]

You can actually get away with leaving the AC and PS on the bracket, and just setting it off to the side. I'd only replace the good gasket if you're going to be getting better gaskets. If you're not, then just leave it alone and change it out when it blows or you get new heads.

 

[BlueOvalStangGT]

Any idea what a good compression ratio is for a 10 year old car?

 

[1105]

Theres no real set compression ratio as long as every cylinder gives you about the same compression as the next. Yours goes form 100 to 138. I'd say its probably your drivers side thats bad.

 

[BlueOvalStangGT]

update: got the dizzy,intake,headers, and the fuel rails. Got 2 bolts out of each acc. braket(2 on both side) but theres one more. I cant find the 3rd acc bolt on the passenger side and the 3rd on is right underneath the powersteering pump. Cant fit a socket in that one and its pretty friggin tight with a wrench so i sprayed some pb blaster on it. Oh and my valve covers, took out all the bolts but the still wont budge. Any ideas? Maybe spray some PB blaster on them?

 

[BlueOvalStangGT]

Got the valve covers off, got the passenger side acc. bracket off. Bolt on drivers side bracket still wont budge. To take out the pushrods, do I just unbolt the bolt on top of the rocker arm, and then slide them out? Then what should I do? Start unbolting the heads?

 

[1105]

To get the pushrods out, you can either loosen up the rockers and turn them sideways and slide the pushrods out or you can take the rockers all the way off and take the pushrods out. Once the pushrods are out, and you dont have anything left on your head, you can just pop it right off. I strongly suggest taking out your spark plugs if you havent allready done that. Cheap insurance so you wont break one off in the head. When you go back to install the acc. brackets, put some anti-sieze on the threads that way if you ever have to take them back off it'll be easy to break them loose.

 

[BlueOvalStangGT]

To get the pushrods out, you can either loosen up the rockers and turn them sideways and slide the pushrods out or you can take the rockers all the way off and take the pushrods out. Once the pushrods are out, and you dont have anything left on your head, you can just pop it right off. I strongly suggest taking out your spark plugs if you havent allready done that. Cheap insurance so you wont break one off in the head. When you go back to install the acc. brackets, put some anti-sieze on the threads that way if you ever have to take them back off it'll be easy to break them loose.

Sparkplugs are out, im gonna try to take out the pushrods now.

 

[BlueOvalStangGT]

That acc.bolt is not coming out. Ive tried a breaker bar, and i've used like 23187312 gallons of PB blaster on it. The whole bracket swivels but that bolt does not move.

 

[1105]

Is that the bolt behind the PS pump pulley? If so, do you have that pulley off?

 

[BlueOvalStangGT]

yes, and no i dont. I am using a open end wrench to try to get it, I cant get the powersteering pump off because the pulley moves unless I have a belt on it, and I dont because I already removed the other bracket.

 

[1105]

That pulley has to come off. Use some pliars to hold the pulley puller in place

 

[BlueOvalStangGT]

People on corral said it doesnt. I tried anyways by wedging a wrench in there, that allen bolt wont budge either.

 

[1105]

Do you have the right kind of puller to get it off? It takes a PS pulley puller... Its a special kind just for the PS pump and it does come off. If I remember correctly... the allen bolt isnt the thing your trying to get out. The puller clamps around the front side of the pulley, there will be a ring where it sits, then you just tighten it down and it comes off just like anyother pulley