I have one or more leaks on my 2004 chevy blazer with 175000 miles. It would be awesome if I could get a bit of help interpreting what is going on. I have maintained this car very carefully always changing oil and doing various fluids and other maintenance, and have always driven it gently (never towed) as a passenger vehicle in an area which doesn't get rust and I don't off-road, this is mostly city and highway driving with the very occasional unpaved road.

After washing, the oil coolant lines quite rapidly become wet. The oil pan is wet. If I drive on the highway for an hour, there is a bad smell and my lungs burn. I can see wet oil and burnt oil on the bottom of the pre-cat. There are drops of oil (or some fluid) on the very flat pan to the rear of the oil pan. If the vehicle is left parked, a few drops of oil appear on the ground.

I wiped the intake manifold gasket and it becomes wet again after wiping.

I added UV dye to the oil, drove it 20 miles and waited overnight. There is a faint yellow-green film on the oil coolant lines under the blacklight. I don't see yellow-green on the intake manifold gasket but there is wetness which is a faint orange under the blacklight. I have looked but I don't see obvious yellow-green elsewhere, although it is somewhat hard to interpret what I am seeing. Unfortunately my camera won't show the UV dye even if I try to filter the light using the glasses provided with the blacklight.

1. I would like a recommendation for a reliable aftermarket oil coolant line, if there is such a thing. Some sources are saying I should use braided steel?
2. Are there other issues here I should be checking up on? Is my intake manifold gasket starting to have a problem?

Additionally I am finding that the rpms are tending to fall to 500rpm and below when idling after starting and/or some driving and the engine nearly stalls and shuts off.

 

Regarding the oil cooler lines, these are known to eventually leak on each 4.3l S-10 and Blazer. Replacing them is a right of passage for Blazer owners.

I replaced mine with OEM ones since I figured the originals lasted over 100k miles.

I also replaced the o-ring and gasket between the adapter between the block and oil lines where it attaches to the block.

You'll need a really long extension.

 

Are newer AC Delco parts worse than the true original parts? Do I expect new AC Delco oil coolant lines to last another 175k miles?

 

The general consensus is that the GM parts are pretty good. There are some parts that the forum members insist should always be used. These are the distributor cap, rotor, and fuel pumps.