Oil Pressure Sender

[Spacenut]

Hi guys - hope you are all keeping safe and well.

As you know I am using the Green Machine for "essential journeys", mainly the weekly food shop. This morning I turned the key and before I had even cranked the engine on the starter, the oil pressure was reading 30 psi

Once the engine was running the pressure increased to a very healthy 110 psi

Since I replaced the oil seal on the distributor shaft there has been no oil leaks on the top of the engine and I think some localised corrosion might be setting in. That said, this isn't the first time this sender has done this too me, so I think it might be on the way out.

I was going to order a new one, but VDO sell both NPT and metric threaded senders. I am pretty sure that the Alfasud sender is metric M10 x 1, but before I shell out could someone kindly confirm this for me?

Thanks everyone!

Lauren

[alfadave]

Sud shop have them.
Not the cheapest, but read his description.

[Spacenut]

Thanks for the quick reply Dave, much appreciated. I've certainly seen higher prices for the same product elsewhere. Not a whole lot of technical description (well none actually), but at least I know it isn't Chinese!

[KevJTD]

may have one in the shed Lauren, come to think of it I don't think I actually have....

[KevJTD]

M14x1.5 Lauren, found a T piece I had on the 16V Sud

[KevJTD]

I also have my patented tool for removing the sender without the hassle of access, there's no room to swing a 22mm spanner with the alternator and carb linkages.
This little homemade tool solves it all.
Available for hire

[alfadave]

Not Chinese, and is accurate.
What else would you want to know!

[Spacenut]

Cheers guys - rather than take a chance with ebay I have ordered one from Sudshop. I might as well treat myself to a new one, the original is 40 years old!

Lauren

[KevJTD]

TBH I've seen original Alfa NOS ones at 3x the price of those, so all things considered it seems a decent price for a good quality part

[dave.armstrong]

Hello Lauren

A few months back I bought a Kerr Nelson SOP141 off Ebay for around £8

I can't see the link on Ebay anymore but it may be worth searching elsewhere.

It is the correct thread and pressure range.

You just need to add a separate earth lead as it doesn't earth through the body.

[Sud 145]

This one Dave?https://www.ebay.co.uk/itm/Genuine-Kerr ... 1926573159

[dave.armstrong]

That's the one!

[StescoG66]

I bought that one too. Works a treat.

[Spacenut]

Thanks guys - well, slightly embarrassingly, I have discovered the hard way that senders in the US of A work on a descending resistance with increasing pressure curve, the exact opposite of our European counterparts. Annoyingly there isn't any apparent way of differentiating between them - same part numbers etc. VDO's own application note reads "0 psi = 10 ohms, or 240 ohms"

Putting a European sender on my US manufactured oil pressure gauge results in the gauge reading backwards. So I have had to order another sender from the US which will be here in 4-6 weeks.

At least I can console myself that Lamborghini would have had the same problem with the early Countach, which used American made Stewart-Warner instruments...

Lauren