Sending Unit? WHAT Sending Unit?

[Tspringer]

I have been questioning the oil pressure reading in my new '69 S. It has a Supertec built 2.6 MFI engine that is 1 year old with 2K miles on it or so. It runs great, is very quick. It indicates low oil pressure.

I spoke with Henry Schmidt at Supertec. HE said he believes its a sending unit or guage issue, but that Supertec will stand behind the engine even though I was not the car owner then and its right at the 1 year warranty date. Henry thinks that since the car is a '69 and the engine is a later 2.7 based hotrod, their could be a problem with the wrong sending unit being used?

First off, the sending unit on this car is not up by the fan as I expected. Apparently its at the very back of the engine, in the center by the flywheel. I dont know if the sending units themselves or the guages were different for the early vs late cars?

Would a late model sending unit off a 2.7 give an improper reading to a 2.0 guage? How do I tell if the car is using the original guage? Is it possible that the problem is a mixed up sending unit?

I am hoping to attach a mechanical guage tomorrow and determine once and for all if there is a problem.

[john walker's workshop]

sender #s
thru 73 #901 741 551 00
74-83 #911 606 111 00
84-89 #911 606 135 00
yes, early gauge w/late sender would not be accurate.

[Tspringer]

Are those part numbers for the guage or the sending unit.

The guage is apparently an early style, because it has the temp in numbers and the pressure not in bar.

I dont have the part number from the guage or the sender yet, but will be digging into it in the morning.

[TimT]

Oil pressure Senders can half fail

I had the same sort of issues with indicated oil pressure. I parked my car after a DE, the next time I drove it, the oil pressure readings were very low.

On my last runs on the track the oil pressure was over 60PSI with hot oil. When I drove the car the following weekend it indicated about 30 PSI at redline with hot oil.

While sweating bullets at the thought of yet another rebuild I checked the oil pressure with a manual gauge, the gauge showed 15PSI at idle, and over 60 at high rpms. So I decided to replace the 32 year old sender and see if things would change.

New sender=good oil pressure readings

[Tspringer]

Tried all day today to figure how to get a mechanical guage hooked up. I bought one from Advance auto parts, but it did not come with a metric adaptor.

It will screw into the sending unit fitting and go a couple of turns before binding, but I dont think enough to prevent leakage under pressure. No body in town had any kind of adaptor.

Im probably going to have to take it to someone and have it fully tested. I want to to know once and for all if the engine is healthy so I can drive it hard without worry.