Blown Head Gasket

[geoffinbc]

Addfire cranks are no more they went even fire in the 80's man. L67's do not get better gas milage. The 3400 is one of GM's best gas milage engine.

[DEI37]

I wouldn't be so sure. A bud of mine with a '02 GTP pulls 34mpg on the highway. I've seen it. I know my 3100 is good for about 28.

[geoffinbc]

Lol your comparing an 02 car to a 97. And cars of different weight an aerodynamics. You probabally do not have the same tires nor are you running them at the same pressure.

[DEI37]

My car is lighter. With narrower tires. Sure, aero plays a part, but not for 6mpg. I run my tires at 35psi, too.

[geoffinbc]

Here take a look at this. 3 egines in the same car same year. The 3400 beats the 3800 and the 3800SC.

http://www.chevrolet.com/impala/specifications/

You dont think aerodynamics play a part in milage. Come on man crusing on the highway and at good clip all you have slowing you down is aerodynamics.

[ryansm1]

Sorry to interrupt the current conversation, but if you don't mind, I have a question.

I've pulled the plenum off, and now I need to remove the fuel rails. It looks like there are two clips around each cylinder that are holding it down around each of the two-pin plugs. Is there any special process of removing this, or can I just pull all of the clips back slightly?

I've attached a picture, in case my explanation is unclear (I imagine that it was). The only semi-clearly visible clip is circled in red, but there should be one on the other side of the metal railing.

Thanks again.

[bszopi]

Keep the injectors attached to the rail (ie, the clips you are talking about). Unbolt the 2 bolts that attach the rail to the manifold (right in the center) and then pry upon the rail at each injector. I usually use a small prybar or big screwdriver to do this. They will fight to stay in there, but will eventually come out. Once its out of the manifold, just set the rail (with injectors still attached) off to the side.

[geoffinbc]

Agreed. You "should" replace all the o-rings on the injectors. But some people get away just fine without doing it. Also when re-installing everything, oil the o-rings and the holes so you dont ruin them when re installing them.

[pepsi_coke]

Oil the o-rings? Hmm .. may be going out of my boundaries here, but screw it .. Doesn't oil eat up / crack rubber and in effect, "break" the o-rings and cause fuel leakage?

Coming from experience ..
Also, when a head gasket is blown, and oil gets in the coolant .. why does the coolant hoses crack? Isnt it because oil effects the rubber ?

[TheProfessor]

no the oil will not mess up rubber
think about valve cover gaskets they are ususally rubber as are other seals

[ryansm1]

Okay, I have another question. :-/

How does the metal pipe that's attached to the water pump (runs to heater core, I think) come loose? There was a bolt that held it on to the pump assembly, and I removed it, but now, the pipe is blocking the front valve cover from clearing the intake.

It looks like whatever is on top used to be socket-shaped, but is now rounded (it's been like that since I've started; I'm thinking that somebody else has pulled the valve covers off before). I can't really tell if it is stripped, or if it isn't supposed to be moved.

Is the pipe supposed to just lift off the pump and I'm not pulling hard enough, or does the thing in the top unbolt from the rest of the assembly?

I've attached another image to clarify what I am trying to say, in case I am mislabeling something.

[bszopi]

You removed the only bolt that holds it in. So again, just try to pry it out...

[ryansm1]

First off, thanks again for all the help. The pipe came loose, but took quite a bit of force.

I finally got the lower intake off, and now I have a question. I'm not quite sure what I am looking for as far as the gaskets go.

There does appear to be a buildup of sludge near cylinder number one (which may be similar to what treeZ24 was talking about earlier..?), and the gaskets by cylinders two and six look damaged, but don't have any signs of leakage nearby.

I've attached yet another image to hopefully help explain it. If you don't think this is it, I have pictures of both heads, and all four gaskets.

[geoffinbc]

Oil will damage certian kinds of plastic and rubber. But not the seals on cars. They are all made to be compatible with oil. If the O-rings were suseptable to oil then fuel would do the same damage. Go and count how many O-rings are in the fuel system alone

[ryansm1]

I have just a few more questions...

I went ahead and bought the gaskets today, but I'm not sure if I should try cutting the gasket so I don't have to pull the pushrods out, or if I should just pull the pushrods. I've been reading/receiving different opinions (one thread and a person are telling me to cut the gaskets, while another thread is suggesting to pull the pushrods and leave the gaskets in one piece).

My concern with pulling the pushrods would be adjusting them after everything is back together. Can the rockers just be torqued to a certain amount and just assumed to work? If not, how much work is it to adjust the rear rockers with the engine back in place?

If I should just cut the gaskets, where are the best places to make the cut, and what tool should I use? I used some clippers to remove the old gaskets, and made a mess of them, might a hacksaw be better?

My final question is this: when applying sealant to the gaskets, should the sealant be on both sides of the gasket, or just the bottom and not the intake side?

Thanks again.