Truck overheated - milky coolant when i check oil
 

1996 4.3L 4 door blazer, over the last 2 weeks the truck has:

1st - it was a radiator hose the blew, so i swapped it out and when ahead the added a thermostat. bought the cheapest one.

2nd - truck began getting hotter abnormally quicker than normal and into danger zone. i turned it off cooled and when i started it back up, a knocking sound came on and off for about 30 mins continuous and stopped. following morning i changed the oil and filter which was about due and has not knocked again.

3rd/last - this weekend it was overheating beyond 260 degrees whiling hauling a trailer load to city landfill. I had to get it home, when i did i left it alone <scared & pissed> till following morning. the first thing i check was radiator fluid level. it was low so i bought new cap/fluid. filled up/ ran / and topped off... when i shut off the engine i decided (obviously too late) to check oil. well the dip stick looked like a effing straw pulled out of a milk shake...

where do i start? was told maybe just the intake gasket but not to be surprised if it needs valve job.

I have access to a decent amount of tools/impact wrenches. really good at following directions and VERY NEW to this forum.

any and all help would be greatly appreciated and welcomed.

Sounds like you popped the headgaskets,possibly warped one of the heads. Time to replace the headgaskets,intake gaskets etc. While heads are off take them and have em checked for warpage/cracks/valves. I didnt and wasted alot of time to find out i warped a head.

A compression test will tell you whether you have a bad headgasket or not. A failed intake manifold gasket can dump coolant into the oil as well.

thanks guys... any other recommendations i need/should do while i gut everything?

its possible that only the intake gasket blew, i took a risk and bought a truck a month back that had similar issues and it was only the intake gasket. probably gonna have to change the spark plugs too if they got all nastified with burning coolant and oil in the cylinders

thanks abig84

i'll go ahead and take a peck at the plugs. any other recommendations / concerns?

Check the overflow bottle too. I had a little bit of oil find its way in there

what should i be looking for when i call machine shops to get the heads checked? should i be asking for something specific?

I would start with a compression test as previously suggested. You may not need to spend the time/expense pulling the heads and having them checked/serviced. An intake manifold gasket set is a lot cheaper, and these engines are known for intake gasket failure. If you find that you have low compression in adjacent cyliders then I would go ahead and pull the heads. If you do end up pulling the heads tell the shop you want them checked for warpage and cracks. While you have the heads off use a straight edge and feeler gauge to check the block decks. Although not as common as a head warping, sometimes they do and it would be a royal PITA to put it all back together only to find you still had a leak.

awesome 01blackbeauty,

i have the the head off... i didnt do a compression check as i decided to go balls to the wall and got a great deal on all the gaskets... i got a machine shop that was reviewed great with only 1 negative comment of 16 and was more than a year back.. anyhow $80 for the set gets them tested / cleaned / resurfaced...