Hello, everyone. First post here, but I have an issue I need advice on and this seemed to be a good place to get it.

I have an '88 S-10 Blazer with the 2.8L TBI engine. It just started dumping oil earlier tonight while I was letting it warm up before leaving work, and as near as I can tell it's coming from a 'fitting' that is attached to where the oil filter mates with the engine. It doesn't seem to be coming from around the filter itself, or between this piece and the block, but rather from the sensor-looking thing sticking out the back. There is a bundle of medium gauge wires just behind it, with a plug of sorts dangling next to it, the plug seems to have one female spade connector in it. I can't seem to find anything it should plug into, however. Most of the oil is actually dripping off this plug.

I've never had a vehicle with this engine before, so the parts connecting to what I describe are fairly new to me. The leak itself is bad enough I can watch it drip about once every two seconds. The small lake of oil under my Blazer is growing at a fair rate, as well. Is this piece sticking out of the back of the oil filter's mounting part the pressure sending unit? If it is, could it possibly leak likethis (out the side facing AWAY from the filter)? The gauge in the dash still works, though it does bounce up and down from time to time. It has done this since I bought it 6 months ago.

A little quick background, the vehicle has only 69k miles, hasn't seen too much hard driving, but *did* travel down a really rough road earlier today (pot holes deep enough for a large cat to disappear in). Is it possible I may have just rattled something loose, and can just plug it back in, or is it more likely I damaged something and it needs replaced? This vehicle is supposed to be my winter transportation, and I can't afford to drop much money into it at this point.

Any advice would be greatly appreciated. Thanks in advance!

 

Here's a couple of quick pictures of what I'm talking about... Sorry for the poor quality, camera phone + flashlight + frozen hands = crappy pictures.

http://i10.photobucket.com/albums/a1...1107081909.jpg

http://i10.photobucket.com/albums/a1...107081909a.jpg

To the right of the wires and plug is the part I mentioned that comes out from the oil filter bracket. As far as I can tell, there isn't anything on that piece that the plug could've come unhooked from. It does seem that this is where my oil is leaking out of, though.

 

that should be your oil pressure sensor. hard to tell in the pics, however I bet it split in half, half has the sensor wire attached and the other half is in the oil filter mount. Try to push the two halves together and then replace it. You might as well buy the special socket while your buying the new sensor. Unless you have very deep deepwell sockets.

 

I took it up to my shop today ('cause my garage is freakin' cold!) and tinkered with it a bit.

Turns out, that plug in the pic really doesn't have a home. There are two 'sensors' coming out of the oil filter mount. One has a plug with two wires, the other has a plug with three. It's the one with the three that's leaking.

I took the plugs loose from them both, determined where the oil was coming from (it's the larger of the two sensors) and it's leaking out of a small hole in the center of the sensor itself in between the three prongs for the plug. That hole did have a small orange cap in it where the leak was coming from, but thatfell out when I touched it and disappeared somewhere above my front axle housing.

I tried packing a bunch of Hi-Temp RTV in there as a temporary fix (since it wasn't a very high pressure leak, only a drip or so per second while the engine was running, not a squirt or anything) but it seems to have found other ways out. It is literally leaking out of the wire harness plug itself now!

The picture attached is the sender I'm talking about. Why my vehicle has two different ones, I know not... I do know that it will run fine with this one unplugged, however... I'm thinking of eliminating it entirely. Perhaps I'll run a mechanical gauge off of it's port.



[IMG]local://upfiles/12684/D2E4C6FC572F4E01B303DE426C078221.jpg[/IMG]

 

Two sensors, one for the gage and one for the low oil pressure kill. It is tied into the fuel pump relay and if it detects low oil pressure it cuts power to the fuel pump.

Replace it.

Check autozones website. They have the wireing schematics on-line and there are different versions. Find your year, also check the years surrounding yours.

 

Ironically, AutoZone's website was the first place I went to in attempt to find that part. The wiring diagram does indeed show the three-wire pressure switch and what it connects to, but they don't have a listing at all for that part in their online inventory. The people who work at the local O'Reilly auto are all idiots, but I still went there to ask them if they had it. The guy behind the counter tried to tell me my Blazer didn't need any of those, since it was carbureted (I showed him my TBI on the engine itself, he only replied with "Oh, so it's an electronic carburetor... doesn't matter."). Also, he was wearing a Manager badge on his shirt.

These are the same people who refused to believe my 1963 Chevy pickup had coil springs in the rear suspension. Showing them that brought about slightly more positive results, they simply figured someone must have "customized" that truck at one point.

Anyway, back on topic. Maybe I'll buy the special socket and go junk-yard hunting for now. I kind of need this vehicle soon, and can't afford to order the sensor new online right now.

Thanks for the replies, though.

 

UPDATE:

Ok, after actually GOING to AutoZone and looking at what they had available, I found the right pressure switch. After much cussing and a few dents in an exhaust pipe from my wrenches, I got the new sender in. No more leaks!

It had apparently been going bad for a while now, since it no longer causes my gauge to jump all over the place anymore. Thanks for your replies, I appreciate the help.

 

Your welcome, and I have the same trouble with our local O'Really's....