Opinions Please!

Not any more common on the 4.3's as opposed to any other engine with 165K on the clock. Hopefully he didn't run it too long and the main and rod bearings aren't cooked. What's the oil pressure like? Run a compression test yet to see what cylinders are FUBAR?

Doc

My brother in law says when I take it apart he will bet on a cracked head,I would think compression would be high with oil in cylinders.I don't think I'll start it again to check oilpresser.I'm gonna soak it down tommorrow with Gunk or something.Then take it down weather permiting.Bobby

If there is a hole on the gasket or a crack in the head compression will be LOW because the compression will escape thru the opening. Think about it.

Doc

that's correct.......the compression is escaping thru the blown gasket. Excessive oil in the chamber would be a totally different animal. If you find oil in the radiator then start shopping for a replacement engine because the block is cracked also.

I took the radiator cap off last nite an theres nothing I can see in the radiator,no water or antifreeze.Thanks! Bobby

I'm sorry but I have another Question.You said Vortec are all 4.3's Vortec engines?Thanks Again Bobby

No....i said if it it has Vortec heads and they are cracked don't waste your time trying to repair them.

How can I tell if it's got vortec heads?I'm busy tearing it down.I haven't got the heads off yet.I've taken alot of stuff off.Hoping things get easier.Get back on it tomorrow. Bobby

The valve covers and/or air intake will have VORTEC written on it.

Doc

Doc, It'a 1988 s-10 Blazer 4x4 4.3 TBI.With water in oil.I didn't see any markings of Vortec anywhere.The water pump is made like the small block V8.So far seems to be a little easier to work on than the 2.8 I have in my 83 S-10 PU.I never heard of anyone repairing any craked head,learn something new every day.Thanks Bobby

The 4.3 is basically a 5.7 (350cid) with the back 2 cylinders chopped off. the 4.3 litre engine is a 90 degree V6, and the 2.8 litre (173cid) is a 60 degree V6. an easy way to spot a Vortec is by looking at the intake bolts, the vortec bolts go straight down and the early heads go in at a angle.

I'm not real familiar with the V6 family and don't even know if GM makes a Vortec head for the 4.3 but i wanted u 2 know about the inherent weakness of the vortec head.

The Vortec head has great flow characteristics but are easily ruined if ya get em 2 hot.

Thanks Mad Dog for the info!I'm gonna try to work on it some more today,I'll let you know what I find out.Thanks Again-Have A Great Day! Bobby

Vortec 4.3's weren't available in the Blazer till 1992. If yours was a vortec, it would say so on the intake cover. H

Hairy, I didn't know that,expells mine then mine is an 1988 4.3.Just came bacik in,its pouring down rain.I'm hoping I can get the heads off without removing the exhaust pipes,just spread the manifolds back.THanks Bobby