Ok, I am new to these boards but I will say I have spent a good deal of time looking over your posts and find they are very helpful in diagnosing problems.

I do not have very much experience as a mechanic, as i'm only 18, but also I am willing to learn.

My 96 Jimmy is not in too bad of shape I suppose,
-143,000 miles
-new felpro intake manifold gaskets(3months)
-I replaced leaking vacuum lines(>year)
-New fuel filter(>year)
-New air filter(>year)
-New Coolant cap(3 months)
-Green Coolant(kinda old)
-new front shocks(>year)
-flushed heater core(3 months)
-New thermostat

The bad


First off it started leaking coolant about 3 months ago so i researched probable causes and found that the lower intake manifold was likely the culprit.

I wanted to do it myself, but instead because no one in my family wanted to help me, i took it to a mechanic.

I did however notice before the gasket was replaced that the coolant built up in a valley above the lower intake when it was running, and when it was cold it leaked on the ground.

I had the job done and when I got it back it seamed fine.

About a week or two after the job I tried to flush out the coolant, but after the radiator drained some it seemed to not want to drain anymore(like 1-2 gallons), so I gave up and just topped it off with new coolant.

So this week I am driving and I notice the waterfall sound I heard when the coolant was low. so I checked the overflow reservoir and the coolant was low again.

Now I am confused, the valley that filled before seems dry, and it is pretty cold today and I did not see coolant on the ground.

It has been gurgling for a couple days but this happened in the course of months.

So my question is
is it still the intake manifold just a small leak?
Could air have been trapped for over a month?
bad water pump? ( I still get heat, and it does not overheat)

I also do not smell coolant in inside of car
I do not think there is an abnormal exhaust content
My oil dip stick was not milky even before i had the gasket replaced

Any help is appreciated

 

The first thing to check would be the hose clamps on the upper rad hose. To do the LIM gasket the upper rad hose would have to be removed. When I did mine I put on new hoses and the upper one leaked for a while. I had to tighten the worm clamp on the intake side a few times until it finally stopped. Your hoses are old, they could be soft, bloated and not allowing for a good seal. Especially if your mechanic reused your OEM band clamps. Those things are crap and one use only. Let it sit overnight and start it in the morning with the hood up and a flashlight in your hand.

Your mechanic should have replaced the coolant when he had it apart. Check your bill to see if he did. If not do it yourself but be aware that the drain valve on the rad sucks. It is easier to slowly and carefully remove the lower rad hose on the rad side and drain the coolant that way. When you are refilling, park the Blazer on a hill with the front end up or use ramps. It is easier to "burp" the system when the rad cap is the highest point. Fill up your coolant and run your Blazer with the cap off, topping up as needed, with the heater control on it's warmest setting, until all the air is out and the thermostat is fully open.