Just noticed a reddish puddle under the 2000 Blazer. Seemed kind of oily, but I can't tell. Has no smell really.

http://www.adamtagarro.com/uploads/blazer_leak.jpg

Another Angle:http://www.adamtagarro.com/uploads/blazer_leak2.jpg

Any clues?

 

That looks like dexcool colant leaking down the back side of your engine, meaning you have a leaking lower intake manifold gasket. It could also be really bad/weird looking Transmission/transfer case fluid, but more likely it is coolant. Have you noticed any decrease in gas mileage or power? If so, it is most definatley a leaking manifold gasket and is most likely getting coolant into your engine oil, which means you need to replace the gasket asap and then get an oil change. Hope this helps.

 

Yeah, I too think that it is coolant. Check your oil ASAP, but typically it'll leak inside or outside, but rarely both unless it is left un-repaired. Check over your heater hoses and all 4 corners of the lower intake manifold (a mirror helps at the back). If you see signs of a coolant leak, plan on replacing the lower intake manifold gaskets sometime very soon.

Also looks like your oil cooler lines are leaking as well.

 

I haven't noticed a decrease in mileage or power. I just did an oil change, and everything looked normal. I'll check the oil tomorrow. What should I be looking for? Is it hard to replace the intake manifold gasket?

 

If the oil is milky, then the coolant has made it's way into it. If this is the case, DO NOT run the engine. You can waste the bearings real fast with coolant in the oil.

The intake manifold really isn't too terrible, but it is time consuming and there are a few things that can be frustrating.

 

So is it something a non car guy could do over a weekend you think? I've got a Haynes manual somewhere....

 

There actually is a very good how-to online. Here ya go - GM 4.3L Intake Gasket Replacement - D-Tips.com

The biggest pain about the whole thing was the bolts that must be loosened or removed to get the driver's side accessory bracket backed off enough to get the intake out. Then there is the difficulty with removing the fuel lines as well as the distributor removal and reinstallation...

 

Thanks for the tutorial link. Well, no milk shake on the dipstick. Still clean oil. I'll have to do a closer inspection next week. I'll post my results.

 

if you change out the intake gasket make sure you get the valve covers on the right sides. i didnt added some time to my repair time : (

 

Unless you want to replace the valve cover gaskets at the same time, there is really no reason to pull the valve covers off.