My question is: intake or head gasket, or what?
Milky oil on dipstick. Dipstick reads high. Water in oil fill cap. Sluggish engine. Water missing from overflow tank.

Just bought this 2000 Blazer 4WD. But this problem started 3 days ago: It started to overheat, I stopped and filled the water. and have driven it lightly since. I got it for a good deal. I hope the problem isn't serious.

 

The problem is serious. Diagnose and fix the failure point immediately.

Drain oil now

I'm thinking you got took. But before you have the lower end rebuilt, PM me.

 

He MAY not have to have the bottom end rebuilt IF it just happened...At the most pull the engine out and remove the oil pan and check the bearings and see if they are ruined.

Honestly it sounds like you got screwed and this problem has persisted for a while. Look for another motor.

 

I drove it for 2 weeks before the water started disappearing. And 2 days before this started, it had got drove hard.

 

A head gasket problem should show if you do a compression/leak down check.
Was it knocking? White smoke from exhaust?
The sluggish feeling could be a cylinder that isn't firing because the plug is getting wet.
Wife drove our cavalier for a few days after burning head gasket.
Drained and flushed oil and water, replaced gasket and had no problem.

 

eitherway, youre gaskets are gone. You need to replace the head and intake gaskets immediately. Flush the motor a couple times and hope for the best. It does sound like you got screwed there buddy. This isnt something that just happens over-night. It was already started before you got it, it just happen to go after you got it.

Hope you didn't pay to much for the truck. BUT the good news is, its kinda easy to fix, as long as the bearing and such aren't destroyed. Just takes time, patience and a couple hundred dollars.

Just did mine bout a month ago, took me 3 days to get it done, not knowing what i was doing.But if you know what youre doing, it should only take 10-12 hours tops. Beest bet would be to go buy the gasket set first, you already know youre gaskets are fried and regardless which it is (intake or heads) you have to tear the top end down, so why not just replace the old gaskets with new, that way you KNOW its new and won't give problems (unless installed wrong).

 

No knock, no smoke. $2500. if changing the gaskets works, its still a deal. lol

 

Check that intake gasket close. It could be the source of your water problem and the head gaskets may be good.

Blazeme

 

If it is the intake do yourself a favor and get the perma-dry metal ones not the OEM plastic replacements.
They cost more but are worth every penny.

 

Just do the intakes, check the gaskets closely for deformities. I got screwed on a TBird 3.8L whose HG always blew, sooner or later.

When I drained to change the oil it stunk with a familiar smell and I realized it was hypoid.. rear axle lube. Put reg oil in and what a racket. I put Mobil1 10w50 in it and drove it for over 60,000 miles with no problems.

The reason the engine didnt blow is because Mobil1 has a much higher coking temp than reg dino oil and wouldnt burn into carbon near that bad bearing high pints which would overheat, it's carbon formation that causes the engine to fail when it finally breaks loose.