I think it broke but I am not sure. Got my motor checked by a mechanic to see if it was dead and he said it's fine and transmission is also good, but problem is a mystery. Was talking to another mechanich a while back and he said that maybe the only prolbem might be the timing belt. I don't know much but if it did what are the symptoms or after effects?

Please ask me questions if I wasn't very clear,

Thank you all for your help

 

.... 1998 4.3 V6 has a timing CHAIN , it is a vortec engine and comes stock with well engineered performance heads ... and it is very unlikely to have broken , even with extreme mileage as chains sort of stretch slowly out of spec . What issues are You having leading You to believe Your "belt" has broken ? What happens when You try to start it ?

 

^^what he said.

I doubt its bad. Tell us some details...

 

My Blazer was maybe bout 5K short of 200K miles, and my dad was driving it to the store and he said that it was sort of forcing its self to produce power, then he got home safely. Then he turned it off, tried turning it on again and heard a loud POP(Like if something had broken). After many attempts to try to turn it on, all it did was try to start but you could hear like something metal was either broken or stuck preventing from it starting.

 

OK Julio ,

Loud pop could be anything really , backfire or somesuch ... if metal on metal noise is going on though and it sounds destructive - STOP! don't try to run the engine until You can get someone more knowledgeable to take a look ... what You are dealing with is a hands-on job .

 

Thanks but don't worry we have it at a mechanic and another mechanic was telling my dad it could just have been the timing chain

 

could also be the starter hanging up/dragging

 

Well i have only heard of one timing chain breaking in all my time spent reading about 4.3's... so yes it is possible but unlikely. If the timing chain does go then i THINK the pistons will start bending the valves because they stay in one spot as the pistons move, which would make a very bad noise. Although im not 100% sure if that actually happens because i think i remember someone saying that wouldnt happen but i dont see how.

 

Cherry is correct. If your timing chain broke, and you tried too start it, pistons would hit valve.

Most of the time valves go into where the piston travels. So if the chain broke, the cam wouldn't turn anymore. And $20 says atleast a few valves are fully open. Bad news.

 

The GM 4.3L v6 is a non-interference engine in that the valves open into reliefs cut into the pistons such that they will not contact the piston even if the valve is open to max lift with the piston at TDC. As such, if the timing chain has broken, turning the motor over will not harm anything. Now if you dropped a valve or broke a rod/wrist-pin/piston/etc, that is an entirely different story.

A very quick way to determine if the timing chain has broken is to turn the motor over with the distributor cap removed. If the rotor spins, then the chain is at least still turning the cam & the cam is still turning the distributor. If the rotor still spins, I would get then line up the timing marks (plural as there are two) on the balancer as described in the EDI Engine Timing thread in the Tech Article (DIY) Section (Index link in my signature below) and see if the rotor points at the pointer molded into the distributor base. If it does, then the cam & distributor timing are correct & the problem lies elsewhere.

If it is not, I would then pull the distributor & inspect the gear at the bottom of the distributor. I have seen several distributor gears chewed to shreds due to misalignment. This can cause similar symptoms to a bad timing chain/gear. If the distributor gear is good, then the problem is likely with the timing set on the front of the engine.

You can also run a compression test, but I find the methods I have noted above to be a quicker path to verifying the timing components. A compression test may still be necessary to narrow down the problem if nothing abnormal comes out of the tests above.