ibought an 94 4.3 blazer,i brougth it home with no problems, loaded thefamily in it andwent for a ride, it started to spark knock, i brougth it home checked the timing and all was good, we went back out andit over heated, we let it cool and came back home,after that itstarted to run really rough. so i pulled the plugs, they all looked fair,number 4 was a lil wet looking. i did a compresion test, all the cyl. tested around 135-150. while i was doing the test on number 2 cyl, coolant blew out of number 4. after the test i checked for coolant coming out of any of the other cyl. and found nothing. HELP !!! is it an intake gasket? cracked intake? or head gasket? or none of the above ?,,,,HELP !!!! PLEASE....

 

sounds like head gasket with out me actually looking

 

how bad do the heads warp on the 4.3? is it a givin' that they be machined?

 

If your compression on 2, 4 and 6are ok (I can't remember what the spec diff between adjacent cylinders isthat would indicate a blown head gasket, but I think it's more than 15) then it's not the head gasket. On the other hand...

It wouldn't make much sense that the Intake manifold gasket would cause you to get coolant in #4 because it is in the middle of the bank and the coolant passages areonthe outsides of 2 and 6. Ditto for a cracked intake. So, I'm thinking bad head gasket. Could do a leak down test I guess to help confirm, but it almost seems pointless in my mind.

That's probably why the last owner sold it off. Just put a crap load of stop leak in there to get it of their hands, if you didn't notice any problems before. Sucks in any case.

 

ok,,the right head gasket is gone,,,problem found,,thanks guys.....next question....i dont have the power sterring pulley puller tool,,,so i cant get the left head off,,,the compression test showed all good,,,spark plugs looked good, ,,,,,should i find the tool and replace the left head gasket? or am i ok with doing just the right??

 

You could only do one side if you want, but you already have 80% of the stuff off to do them both. With the heads off, I would also replace the valve seals and maybe re-lap the valves.

 

You can borrowa pullerat most of the major auto parts stores.

 

sorry it took so long to finish the post,, it was the head gaskets for sure,,the heads were nice and flat only 1-2 thous out, not bad at all,,, i took them to my shop and milled10 thous off of both, cleaned them up a lil, magnafluxed them,no cracks,all the valves checked out fine, flushed out the oilpan, put itback together and it runs fine.

 

Great that you replied back. At least it had a happy ending.