My 1996 Blazer 4x4 automatic was showing high oil pressure then when driving down the road just cut off. Now just cranks and cranks with no fire. There is now a not metal on metal noise but a definite clunking noise when it turns over.
Any idea's I was thinking oil pump?




Thanks
John

 

Any metal shavings in the oil?

 

No the oil is clean as clean can be

 

I have thought about this for a few days and can come up with only 2 scenarios which are not for certain either:You either threw a rod bearing or broke a connecting rod itself. These both would have provided symptoms(noise)well prior to this occuring I would think!
Another possibility is a broken timing chain or sprocket.Both of these account for a clunk while cranking with a no start however.I'd bet on the timing though! Pull a valve cover and see if the rockers are moving when you crank it,if not,thats your culprit!