I just went through and replaced my timing chain because I've had issues with timing on my 99 zr2 s10. Got it back to gether couldn't get it to start at first seen my crank sensor had some wear on it from the crank though maybe thatd be an issues so went and bought a new one and didn't want to start swapped back in the one with wear got it started. Then started putting my coolant back in the system and noticed white smoke start coming from the exhaust finished my second bottole of coolant went to the house to fill up with some water came back noticed water pouring out the exhaust at the back of the truck and were I have a leak.

I'm thinking it could be a bad head gasket, bad head or cracked block. Anyone else ever have the fun of this before? I"ve had issues with timing not being able to be dialed in properly. The truck up and stopped running which is the reason I went and replaced the timing chain. to attempt and clean up the messy timing issues.

 

could be one of two things, 1) headgasket like you said 2) lower intake manifold gasket as those are common. do a compression check to test the head gasket and if checks out than more than likely its the intake gasket. do a coolant pressure check and see if your loosing pressure.

 

How well is it running? any ticking noises, popping through the intake? I assume it was running fine or at least ok before taking it apart? the timing chain wasnt broken before you replaced it was it. Kindof worried that the cam was set up out of time and it bent a valve and jammed it into the head hard enough to crack into the water jacket or jammed over into the cylinder wall and cracked the block. Dont freak cuz i havent heard of this happening very often but its a possibility. Pretty unusual to do a timing chain and suddenly blow a head gasket while its taken apart, let us know what you find.

 

i'm gonna check the intake gasket. Was told that was a good possibilty that is the issue. as it is a normal occurance. I replaced the gasket once cause I thought it was leaking not coolant