Gasket replacement hell...help!

[Skizzot]

I just replaced the intake manifold gasket on my 2000 Tahoe 5.3L and have a SERIOUS problem. After replacing the gasket and reinstalling all of the components I started the vehicle. It fired and ran for about 3 seconds, followed by a clunk and dying. I pulled it all apart again, checked everything and reassembled. Upon starting again, it fired, had some "clunk, clunk" noises in addition to erratic idle and then died. I'm fearful to restart it again. Any ideas....especially about the "clunk" sounds? Thanks!

 

[Rivieraracing]

Could you have dropped something down the intake when you had it off for the gasket?

 

[jplinville]

Did you account for all the tools, nuts and bolts? It almost sounds as if you may have dropped something down into the engine...

 

[04SS99Denali]

clunk as in the motor chugging to a stall? i think thats what you mean not a clunk from somethinig in there right? lol im being possitive here


edit : if something were dropped down the intake your in for a big repair bill

 

[WoldD90]

Did you torque everything down to the correct foot pounds?

 

[M3PO]

clunk as in the motor chugging to a stall? i think thats what you mean not a clunk from somethinig in there right? lol im being possitive here

Sounds like this very well could be it, I missing motor will clunk and chug.
Best bet is to tear it down, if you can't find something out of place that would cause the motor to miss.

 

[Skizzot]

We were using two separate tool boxes but everything appears to be accounted for. I plugged everything up with shirts before cleaning the area to seat the new gasket. Upon hearing the sound, I pulled the intake manifold and inspected the valves. There were none bent or damaged; however, one was partially down while the others were up. The clugging preceded engine stall so I'm at a loss as to what to do.

 

[M3PO]

If you are sure you don't have any loose items in the motor. Maybe disconnect coils, fuel pump, or whatever so you can use the starter motor to turn the engine over? If there was something loose in the motor, the damage is most likely already done.
If it clunks just rotating by the starter, you more than likely have a internal mechanical issue. If it doesn't, you have a good chance it is missing and chugging do to something else (not running right).
Or if you are not sure you are going to grenade the motor, take it to a reputable shop.

 

[Skizzot]

The only possibility of something dropping in the intake is whether something was sitting in a manifold crevice that couldn't be cleared with shop air prior to pulling it. I'll turn it over without coils/fuel pump and listen for any abnormalities. Thanks.

 

[Rivieraracing]

If you are sure you don't have any loose items in the motor. Maybe disconnect coils, fuel pump, or whatever so you can use the starter motor to turn the engine over? If there was something loose in the motor, the damage is most likely already done.
If it clunks just rotating by the starter, you more than likely have a internal mechanical issue. If it doesn't, you have a good chance it is missing and chugging do to something else (not running right).
Or if you are not sure you are going to grenade the motor, take it to a reputable shop.

Excellent idea!!