I have a 2001 4x4 blazer with a 4.3. while I was out today smoke started coming out from under the hood. Stopped smoking with 30 seconds of turning the engine off. It smells like oil. Checked the oil and it's barely showing on the stick, so it's down almost a quart in like one mile. I've driven it nearly every day for the last year and not had a problem with it using oil. My question is: where is the most likely culprit for a sudden loss of oil? Diagrams very much appreciated, I've worked on a lot of vehicles but not this one yet. I don't have a jack or ramps and it's next to a fairly busy street so I'm not super comfortable with spending too much time under there. I'd like to have an idea where/what I'm looking for. I've got a place to take it for the actual part changing, but it's in the opposite direction of the part store I'll have to walk to and get the part, I cannot afford to drive it too much and risk the engine.

 

My thoughts: oil filter, remote oil filter lines, remote oil filter adapter.

Probably going to be quite a mess under the engine, likely need to spend some time just getting oil wiped-off, add oil, then start engine and start looking for the leak.

 

I agree with LannyL81. The oil cooler lines are a big culprit on these trucks. On the driver side where the oil filter mounts they connect. And yes if they went bad it'll be a mess under there. Also it'll be a pain to work on them. But you do NOT want to drive it any great distance like that. even if you fill it with oil it'll flow right back out in minutes. Literally.

As a side, if it is the oil coolant lines, just so you know, you can remove them safely IF you don't do any kind of heavy hauling. I've had 4 blazers and a 96 Sierra pickup with the same engine. they have all had those lines bad. In my present 2000 blazer I took the lines out and my 96 Sierra didn't even have the lines installed. And take into account I am in Texas, hot as Hades, I have not had any overheating issues without them. But I don't do any heavy towing. You simply remove the hose, and when you take the filter off there are two bolts that hold the adapter to the engine. Remove those and take the adapter off. Then simply crew the filter back on and up to the engine. Done.

But if you put some oil in the truck and start it, find the oil coolant lines. You will want to pay attention where the metal compression connectors mate to the rubber lines. that's where they fail. You'll see it spray outta there.

 

I had a sudden oil leak due to the o-ring at the adapter between the external.oil lines and the block.

When this o-ring is replaced is a good time to also replace the hoses.

If you do the work yourself, a trick I learned for keeping the paper gasket in place during assembly that is also between the adapter and the block is to use a little bit of Vaseline (petroleum jelly).

 

Check the oil pressure sensor on the back of the engine under the distributor. The rubber diaphragm can fail in those things and send oil squirting out through the electrical connector. I replaced that in my dad's Blazer not long ago.

Just check for an oil leak. To remove the sensor, you'd have to pull the distributor, unless you have flexible hands that can fit under it to screw out the oil pressure sensor.

 

I forgot to come back and update. It was the oil pressure switch leaking.

 

glad you found it!

And thanks for the update.