Oil pressure sending unit location, 350 Engine?

[ClydesdaleKevin]

Hey guys,

Anyone know where the oil pressure sender is on a Chevy 350?  I looked all over on line, and the concensus was that its next to the distributor, but not on mine!!!

There appears to be some sort of a sensor on the side of the engine block on the driver's side, just below the spark plugs and just about in the middle.  It looks like it could be either a OP sender, or a water temp sender...I guess if I unscrew it I'll find out right quick, but does anyone know if that is the oil pressure sender?  The gauge doesn't work and there is no wire going to this sender.

The water temp gauge doesn't work either, so I'm a bit puzzled.  Anyone know where the original water temp sender would have been as well?  There is an aftermarket setup in the thermostat housing, but I'm not sure if this was the stock location.  It has a wire going up under the dash for an nonexistant aftermarket gauge.

I really need both the gauges to work!  The clock and the volt meter work though...lol!

This is the Chevy 350 in our toad vehicle, a 1985 Chevy k5 Blazer.

Thanks!

Kev

[pvoth1111]

back by the distributer I believe.

[Froggy1936]

Hi Kev The original spot is under the distributor There should be a plugged hole . The original temp sender was in the L/S cly head between the first and second spark plug There is a duplicte hole in the R/S head between the third and forth spark plug either will work The only hole on the block just above the oil pan is a  water drain hole on both sides  On my 95 block the knock sensor is in the R/S  These lower holes would work but are usually cooler and highly susceptible to getting sludged closed with rust .  Frank

[LJ-TJ]

Got a picture  Hm?

[ClydesdaleKevin]

Haven't got a new camera cord yet, so no pics yet.

Nothing at all behind or near the distributor, but it is a brand new engine so an OP switch might not have been added...I'll look for a plug!

Sounds like the sender on the side of the engine might be water temp...but I'll pull it tomorrow and see what seeps out of it...oil or green water...lol!

Kev

[Rickf1985]

Judging by the position of the sensor on the side of the engine it could also be a knock sensor. It has been quite a while since I worked on an older 350 but I could swear the steering shaft came into play when trying to get to the knock sensor on a lot of vehicles. You say this is a "new" engine. As in new in the crate? It is not an LT-1 is it?

[circleD]

I'm just jealous now. I love the old school blazers. I'm only familiar with the Gen 1 Vortex. I'll check some of my books though.

[ClydesdaleKevin]

The block appears to be iron, so pretty sure not the LT1.

I bought an aftermarket oil pressure gauge and water temp gauge, which I'll be installing later today, so I'll look for a plugged hole near the distributor.  Just not a lot of room near the distributor on this thing!

Kev

[circleD]

I found 2 differant models.  LE8 / LE9

[bluebird]

The LT1 blocks are cast iron. There are two places to have oil pressure on a sbc. Right behind and a little right of  the dist, and right above the oil filter. The preferred location is behind the dist, because that place is after   the cam bearings and will give a true reading after the oil has passed through the engine.  If you use the lower plug, it can give a false reading, if the bypass valve is held open for any reason. It'll show pressure, but the top of the engine may not be getting oil if the bypass is open.

[Froggy1936]

Hey Kev, look at my project Changing 3 speed to OD trans, Page 2 reply 36 & 38. In 36 you can see exact location of oil gally tap (red bolt in hole) and in reply 38 second pic the brass t with pressure sending switch and opening for mechanical gauge.  Frank

[ClydesdaleKevin]

Thanks guys!

I found it!

What was confusing me was the Edelbrock Performer intake manifold.  It looks a lot different from internet pics of the stock setup!

I found a picture on an Oldsmobile forum from someone with the same dillema, and their solution to the clearance issues of a stock OP sender:



Once I saw it in relation to an Edelbrock intake, it was easy to find the shiny bolt plugging the hole!

I spent all day on the ignition switch and key cylinder...that's an epic I'll put in my travel blog...so now that I know where it is I can add the sender and aftermarket gauge tomorrow.

My eventual plan is to have the stock gauge work as well, so I'll have to come up with some sort of T fitting, but for now I'm just going to put in the aftermarket gauge and sender.

Thanks everyone!

Kev

[DaveVA78Chieftain]

Item 2 fitting
Item 3 pressure switch


It's amazing what you can find in the "online" GM parts book! 
Even has P30 data   

http://www.gmpartseast.com/Page_Product/PartList.aspx?MakeUrl=chevy&CatalogUrl=1985-blazer&ComponentCode=TA0001204&SectionCode=00&EngineCode=LF5&TransmissionCode=&ModelCode=K10516&Vin=&ProductionDate=&VehicleInfo=&CatalogCode=52R&Year=


Dave