head gasket

[schroader]

I put new head gaskets on my truck. And some more heads, put it all back together and now it runs worse than what it did with the blown head gasket. Misses like crazy wont even pull its self out of its own trackes. Any idea of what it mite be.

 

[MAKG]

There are a BUNCH of easy pitfalls. Like leaving a connector disconnected or a vacuum line off. Like putting head gaskets on backwards (astonishingly, it IS possible). Like breaking battery cables. And so on.

Start with the engine self tests.

 

[schroader]

There are a BUNCH of easy pitfalls. Like leaving a connector disconnected or a vacuum line off. Like putting head gaskets on backwards (astonishingly, it IS possible). Like breaking battery cables. And so on.

Start with the engine self tests.

The check engine light is not on. No vac. lines left off. What is a breaking battery cable. There wasnt but one way the gaskets went on.

 

[woodyedmiston]

Gaskets

Let's assume you got the gaskets on correctly and you have reconnected all vacuum lines. Have you checked for a vacuum leak between the aluminum manifold and the plastic plenum. With a relatively cold motor, start the engine and then spray a little Berryman's B-12 around the point were the two bolt together - very common for a vacuum leak there. If you have a leak the Berryman's will make the motor speed up briefly. First check the bolts and make sure they are tight. If it still leaks you might need to replace or re-glue the gasket. Without disconnecting much, you can take off the six or eight bolts that hold the plenum on lift it straight up and replace that gasket using an appropriate amount of RTV on both sides. Snug the bolts down and your leak should be gone.

Stay away from the exhaust with the Berryman's the stuff is flammable.

 

[Bird]

Actually, the head gaskets can go on the wrong way - there's specific markings embossed in the gaskets for which side / direction the gaskets go on.

A lot of troubleshooting you still have to do - do a compression test, vacuum leak test and make sure that you got the plug wires back into the proper coil terminal - then go from there.

Bird

 

[krugford]

+1, I'd start with making sure the plug wires are correct and check all the plugs.

 

[Guy]

You'd be amazed how easy it is to miss something when doing a job like that. When I put the new heads on my 4.0, the thing ran like shit and it turned out I had disconnected the plug for the right bank o2 sensor and forgot to plug it back in (the damn thing was hiding on the back of the engine- I dont know why they would put it there)

 

[MAKG]

(the damn thing was hiding on the back of the engine- I dont know why they would put it there)

To keep the O2 sensor wiring off the exhaust manifolds. Wires don't like that.

 

[Guy]

To keep the O2 sensor wiring off the exhaust manifolds. Wires don't like that.

Good to see you again MAKG, been a while since I have been on the boards. Very true, but I am sure that you knew I was being sarcastic.