Hello, I have a 2002 Blazer zr2. I have noticed a very slow dexcool coolant leak dripping below the airbox side of the motor. In looking underneath, I can see coolant that has collected over what appears to be the underside of the engine block on the far right (and lowest) pulley but I cant tell where its coming from. The hoses on that side appear to be ok unless I cant see something. I have 2 pictures I snapped from inside the oil filter hatch and you can see where the majority of it is collecting before dripping to the ground. Any help you guys can offer as to where this coolan leak could be originating that its so slow, maybe 3-4 drips after running. If it helps, on the top right of the radiator there is the upper hose and directly beneath that is a steel tube fitting that I notice a small amount of coolant around but it doesnt appear to be leaking down the side of the radiator, it appears to be down where the pictures show. Thanks again all.

 

looks like it could be the water pump

 

Take a look at where the lower intake manifold meets the block near the passenger side of the A/C compressor. If this area is wet, then your lower intake manifold gaskets are bad. It is a common problem. When you replace them, make sure that you get the updated felpro gaskets with the metal frames instead of the older plastic frames.

 

if it is a coolant leak, you will smell a fishy type smell
if its that small then you prob wont
the radaitors these days have plastic ends and they are common to leak
around there
theres nothing you can do but replace the radiator
but for a leak that small i would wait till it gets worse
mine didnt look like it leaked around the sides until i took it out
where i saw the coolant was around the back of the engine
and i had it checked out and there was nothing wrong
but they found a radiator leak and it fixed the prob

 

Thanks everyone for the posts so far, things appear to be dry underneath the water pump, it looks like the leak is lower than that. Ill need to check the intake manifold as suggested as well as try to look at the backside of the radiator more closely. I have heard of the intake manifold gaskets going bad especially with the Dexcool, has anyone had this repaired in a shop before? Ive heard its extremely expensive. Thanks again all.

 

i just done my lower intake gasket by myselft. It's alot cheaper that way.

 

too bad you don't live close. i'd help you out. i have a buddy that works in a garage and he said the books say it's a 5 hour job. So whatever there hourly rate is times 5 plus parts and that's what it would cost ya. I'd say probably around 4 to 5 hundred

 

Honestly, neither one of those pics look like a coolant leak. The first pic looks like leaking power steering fluid, and the second pic looks like a seal failing letting oil leak out. If you touch either area, is the fluid brown ( oil ) or clear ( power steering fluid ) or red for the coolant?

For some info on Dex, check this site out www.dex-cool.net It is based on the 3800 V6 engines, but much of it will apply to these 4.3s also.

 

Still am a member over at BC.com but no longer active. I have seen that article before. Good write up, but I do not like the comparison as it is two different vehicles. IMO, to writeup something with information that in depth and not do a comparison on the same motor after a certain number of miles... Even at that, batch to batch process variables can come into play...

I have personally seen and repaired failures of 100% green (standard), yellow (extended life), etc OAT (as almost all coolants now are) coolant filled 4.3L engines using stock replacement gaskets. Two of these cases were friends of mine and repeat failures (under 30k miles). The final nail in the coffin was to replace the gaskets with the updated, metal framed gaskets. Point being that the gaskets GM originally designed SUCK and aftermarket gaskets initially were VERY poor copies.

The discussion of Dexcool as a coolant has been done in another large thread which anyone is welcomed to read through and give $0.02.

 

I didn't post that up as a 100% dex cool is the problem, just as a thought. Sorry if it was took that way, not how it was meant Also, at the bottom of the page, he suggests for everyone to do their own research.

Agreed though, it is a good writeup. Best that I have seen to date despite the flaws.