1997 malibu. 100 000 KMS.

The intake manifold failed so my friend and i took the engine apart. installed new head gaskets, and new intake manifold gaskets. cleaned everything up. followed torque specs. and put engine back together, new oil, new collant, new spark plugs etc.

initial startup...engine has hard time starting, when running the engine is VERY ROUGH, sounds horrible. engine eventually dies on its own after about a minute or two. sharp metal squeealing noise then a bit of a seize noise when engine stops.

any ideas? one thing we cannot figure out when we connnected the wiring harness to plugs etc is that there is a connector with orange weather seal (orange connector lets call it). we cannot for the life of us figure out where this plugs into. this orange connector is coming off the main harness. and we'd like to know where it goes, maybe it well remedy somthing.

this is my second 97 malibu to have failed under 150 000 km.


please help me if you can. much appreciated.

just curious, did you put a lot of coolant back into the motor? Keep in mind the coolant circulates from the motor to tranny and back.
When you added the coolant back into the motor, did you allow the pressure to build back up with the motor runnin' and the radiator cap off...

Before we started the engine we added coolant and had the breather loose until coolant started to come out. thats about all we did in regards to the coolant. why?

Sounds like for the rough idle there may be a vacuum leak somewhere, or miss-routed plug wires. Running the engine to operating temp with the cap off allows for air bubbles in the system to escape, air bubbles will cause overheating issues or not reaching operating temp. The noise may be coolant or some other fluid on the belt, sometimes that can sound horrible. Can't really say for sure though without seeing and hearing it. Did you pull the coolant out of the cylinders when you had the heads off? Just another suggestion though, I'm not trying to be mean or anything. As for the connector if you could take a picture and put it up that would be helpful. I hope this helps some.

I'm about to do this! Can someone give me some tips of things I cannot forget when changing the head gaskets