Oil pressure sensor on 454??

WYScott · 09-30-2005, 07:23 PM

Hello- Scott here, putting finger to keyboard in Jackson, Wy. I'm helping a mechanically challenged friend square away the '82 Airstream 310 that he bought last fall.
The needle on the oil pressure gauge sits unmoving at 4:00pm. The engine runs fine, other gauges WNL, so I s'pect it's probably the oil pressure sensor. Pretty simple fix, right?
I can't find the oil pressure sensor on the engine. It is not behind the carb near the distributer. I have crawled around underneath and can't find it. I have a replacement, so I know what it should look like.
Is there a secret that only Airstream folks know? A conspiracy to befuddle us shadetree mechanics? Does any body here know where the &%#*$ thing is located?
And BTW, that motorhome is one beautiful piece of work, very nicely done.
Thanks for any help you can provide.

overlander63 · 09-30-2005, 07:42 PM

First, welcome to the forums.
Second, there are very, very few 454's with the sender for the oil pressure gauge on the front of the engine, almost centered in front of the intake manifold. Even fewer have the sender in a spot just over the oil filter adapter housing. The fact that you can't find it may indicate it has broken or fallen off, although you would see a huge puddle of oil on the ground if that happened. Is the gauge electrical or mechanical? That is, does oil flow into a tube that goes to the gauge, or is it a wire?

59toaster · 10-01-2005, 10:47 PM

Really Depending on what Generation it is. It can also be on the side of the block in front of the driverside motor mount. Thats where it is on my 88 Suburban.

TomW · 10-02-2005, 05:18 AM

Quote:

Originally Posted by 59toaster

... It can also be on the side of the block in front of the driverside motor mount. Thats where it is on my 88 Suburban.

That's also where it is on my '84 Suburban; I believe a green wire is connected to it.

Tom

59toaster · 10-02-2005, 07:31 AM

Quote:

Originally Posted by TomW

That's also where it is on my '84 Suburban; I believe a green wire is connected to it.

Tom

Actually there may be two sensors there. On anything from about 81 up it would require two sensors the way GM set it up.

On my 88 (Fuel injected) its one for the gage and one for the Fuel pump that if it isn't running it shuts down the fuel pump.

84 one would be for the Choke (only delivers power to the choke if the engine is running) and the other would be the gage. The second senors could still be at the oil filter boss as well.

I haven't really looked but I don't think the 454 has a oil port behind the distributor like the small blocks do. Its a rats nest in that location on my truck with the fluel lines for the TBI and MAP sensor and a few other lines back there.

overlander63 · 10-02-2005, 07:46 AM

The second sender is really to shut down the fuel pump if you lose oil pressure. Not a bad idea, since most people don't check their gauges often enough. Like people that run out of gas...

59toaster · 10-02-2005, 08:18 AM

Quote:

Originally Posted by overlander63

The second sender is really to shut down the fuel pump if you lose oil pressure. Not a bad idea, since most people don't check their gauges often enough. Like people that run out of gas...

Its a very nice side effect thats for sure!

Its primary intent is to save the battery if you put it in Run without starting the engine. That pump has a heathy draw. The FI will prime the pump for 5 seconds for starting then it will turn the pump back off if till it has oil pressure. GM vehciles do not cycle the pump once it reaches pressure. The pump runs continuous.

Also if the vehicle is in a wreck and the motor stalls it keeps the fuel pump from emptying the tank if a line is ruptured. The in tank pump with no pressure to fight will empty a 20 gallon tank in about 7 minutes.

On the electric Choke vehicle its intent was again for you not to accidentally cycle the choke if you put it in run and didn't start the engine. This prevent you from having starting problems in the winter. It also keeps the draw on the battery down if you inadvertently get it in Run without starting.

swebster · 10-02-2005, 04:24 PM

In front of the drivers side motor mount is where it's located on my 86 345. There are two. One for the gauge and one for the "other" stuff.

overlander63 · 10-06-2005, 09:03 PM

Quote:

Originally Posted by swebster

In front of the drivers side motor mount is where it's located on my 86 345. There are two. One for the gauge and one for the "other" stuff.

An SOB Motor Home came in today, with, of all things, a blown-out oil sending unit. Where Steven's sender is, is also where the sender was on this one. Not that it matters, it was a '92 model, doing its best to emulate the Exxon Valdez on my shop floor...

WYScott · 10-07-2005, 11:38 AM

Thanks for your help. I was out there yesterday, crawled underneath, found the sensor and the wire was off. I cleaned the cotacts and plugged it in. The gauge is still pegged to the right. I didn't have time to mess with it, I'll check the connections and do some more troubleshooting today if I have time.

ALANSD · 10-07-2005, 11:42 AM

is the gauge pegged without the power on? I wonder as I have had mine stuck to the right and tapping on it or turning the key on and off released it to its proper spot.

smily · 10-07-2005, 11:45 AM

The sending unit can be replaced in about five minutes.

overlander63 · 10-08-2005, 06:47 PM

Quote:

Originally Posted by smily

The sending unit can be replaced in about five minutes.

And the best thing is, it will probably be the cheapest thing you replace on your engine. The senders can cost as little as $1.99, depending on type.

59toaster · 10-09-2005, 09:19 AM

Quote:

Originally Posted by overlander63

And the best thing is, it will probably be the cheapest thing you replace on your engine. The senders can cost as little as $1.99, depending on type.

At Autozone Its about $25 for a gage sender. Idiot light sender is about $4. The pump or choke switch is about $14

At the dealer double the prices above.