99 Blazer 4wd, 158,000 miles.

Ok, so if you look at my previous thread in May/June, you'll see that I replaced everything in my cooling system, except for the heater core and the manifold gaskets (which had been replaced several years back, when the system was still running with Dex-Cool). I flushed and put in prestone gold with no intention of looking back. Many thanks to this forum for hints and tips that saved hours of frustration.

Everything was Jim dandy until this week when I noticed that I had almost no coolant in my overflow tank. I didn't have any coolant to add to it, by the time I drove across town to get some, my temp spiked....not all the way, but close. I added a gallon, but it wasn't enough. In all total I added close to two gallons between the tank and the radiator.

When I was able to pull the radiator cap after the engine had cooled down, there was sludge on it that was about the consistency of old, caked on grease. It smelled like burned oil.

So, it would seem (if I've read correctly) that I'm due for a Lower Intake Manifold gasket replacement. I also seem to remember reading that I should check the compression of each of my cylinders.

The engine oil on the dip stick appears to be non-contaminated.

Am I on the right track, and if so, is there anything else I should take a look at or replace while I'm @ it? (aside from a coolant flush, an oil change, and replacing the radiator cap, again).

Thanks,

Jonboy

 

You should try putting a radiator pressure tester on it, with it pressurized you should see where it is leaking.
AutoZone has a loan a tool tester you just buy bring it back and it ends up costing nothing
I work there
It seems like if water is leaking into oil you would see a chocolate milkshake crud in the oil and the oil dipstik would be way past full mark
Hope things work out for you!!!!

 

Heh... when you responded I had just literally left Auto Zone with one of those as well as a compression tester. We'll see what they yield in the morning.

My father is trying to convince me to use bars leaks I.stead of ripping the manifold off....

Jonboy

 

Ok, so I feel silly now... I put a pressure tester on the system and found two leaks - hose clamps weren't tight enough...(I didn't see the leaks when the engine was running) I tightened them, and pressure tested the system again, and it seems to be steady...

I pumped it up to 18 psi...

@ 3.5 minutes it had dropped to 17 psi
10.5 min dropped to 16 psi
28.5 min - 15 psi
51 min - 14.5 psi
81 min - 14.2 psi

so, I think we're good. I'm gonna still check compression, because I need to change the plugs anyway.

If I have time, I'll flush the cooling system again, because there is some foreign contaminent in the system...

Thanks,

Jonboy

 

If it looks like rusty mud that is dexcool crud back flush it but you may never get it out I still have the crud in mine.
I'm glad it as nothing major that pressure tester saved me, I thought a freeze plug was leaking till I hooked up tester and saw my heater hose peeing and dripping down engine looking like it was by the block and the plug under the motor mount. things are not always what they seem.