Oil pressure sender

[chrisd0729]

I have a 2017 BDR with the Iconic 427 and 600 miles. The oil pressure was reading about 10 at warm idle and 30 lbs driving at 2k rpms. Didnt sound right for a new engine and proper oil level so i ordered a new vdo sender from BDR. I installed it yesterday when also changing the oil with Brad Penn 10w30 green with high zinc (recommended in bdr manual). The gauge is now reading over 100lbs at idle!

I used a Purolator One filter, cant imagine thats driving the high pressure.

I was thinking swap back to original sender and see what pressure is? What are thiughts on how to troubleshoot the high pressure and figure out what it really is?

[spdbrake]

I would remove the sender and install a direct pressure gauge on the sender port. It will rule out wiring/sender/gauge. (Available at Home Depot etc,,don't fret if its Oil proof or not and designed for water. Consider it expendable)
The new sender you have may be a "common ground" type and wrong PN for your gauge if it is the "Floating Ground" (variable ground) type. Thus the peg to 100psi you see now.
Since engines usually have a 24 mo warranty, I'd contact Backdraft if its a pump issue.

[bobcowan]

Sounds like you bought the wrong sender for your gauge.

Get an inexpensive mechanical pressure gauge and hook that up. Most auto parts stores will have one on the shelf. They're usually pretty accurate; accurate enough for this anyway.

[chrisd0729]

Great point, I’ll grab a manual gauge today.
Just thought... i used Teflon tape on the threads. Shouldn’t have done that... i assume it blocks the ground? I’ll also try reinstalling the new one without tape.

[bobcowan]

Use teflon paste, thread sealant, instead of the tape. Not because it blocks the ground, because it doesn't. But because the tape can end up in the oiling system. If you bought the complete gauge (instead of just the sender), the instructions specifically tell you not to use tape.

As an example, here's the instruction sheet for autometer gauges: https://www.autometer.com/media/manual/2650-1079.pdf They specifically tell you to use the paste.

[MaSnaka]

If its an electric gauge you might check that the wire gauge is big enough. I found my gauge was wired with too small wire from the sender to the gauge and was giving me a falsely low reading.

Good luck
John

[t walgamuth]

Is it reading 100 psi when fully warm? That seems ok if only when its cold with fairly stout oil in it.

[Gaz64]

The OP says over 100 psi at idle, which is certainly abnormal.

When chasing an oil pressure issue, a master oil pressure gauge or at very least, a mechanical oil pressure gauge needs to be fitted to the engine.

While this is being hooked up, the gauge circuit can be tested.
Generally the sender wire grounded with the key on should read zero on the gauge.
A decade box is a handy tool for testing gauges if you have the sender resistance specs.

Gary

[t walgamuth]

I have had numerous engines which pushed over 100 psi when cold then when fully warm it may come down to 30.

My current engine in the Cobra is a SBC. I'm pretty sure it pulls over 100 when cold. My old Ferrari GT 250 would pull 140 when cold. My recently sold Lotus 7 replica with Accura K20 pulled well over 100 when cold.

I agree to put a mechanical guage on it though to be sure what is going on.

[chrisd0729]

Got to work on it this afternoon and here's what I found....
1) The sender I got from BDR isn't the correct one so that explains the 100+ lbs from that new sender!
2) Before reordering the right sender, I took the advice of testing with a direct gauge I just picked up today. It's getting 60 lbs at idle (900 rpm) on a cold start and then about 35-40lbs at idle after warming up. The oil temp was showing 100 c so, about 212 f.

With the in-dash gauge, it's showing 40-45 lbs cold and about 10 lbs at warmed up idle. Sounds like it truly is the sender? Not sure how to test this vs. the gauge; any suggestions? Here's the sender I'm using (which I can't actually find anywhere online except for case packs at alibaba).
.
.

[cycleguy55]

Why don't you just switch to a mechanical gauge and be done with it? Virtually every electric oil pressure gauge I've seen has a matching mechanical version. Easy swap.

[spdbrake]

If you can get the PN off the back of your gauge, just give VDO a call for the correct sender PN.
VDO - USA
http://www.vdo.net.au/media/189570/2...-catalogue.pdf

Using a snake camera (borescope) you can usually get easy access.
https://www.amazon.com/gp/product/B0...d_i=4989317011

But VDO PN 360-006 looks like what you need. Still a guess not knowing your gauge PN. (Doesn't have the redundant warning switch which your not wired for anyways)
https://www.amazon.com/VDO-360004-15...ywords=vdo+360

[bobcowan]

I like electric gauges for street cars. I don't like hot high pressure oil inside the cockpit. I guess I'v had too many leaks over the years. No sense replacing what you already own and is (probably) working fine.

I would replace the sender with the correct one and see where that takes you.

In the mean time, go through the wiring and make sure it's all in good shape. Solid connections, no kinks or damage, etc. If it is, and the current gauge is working fine, move on! Life is too short to worry about minutia.