boxburn

I have just got a new oil pressure sensor but it won't screw in. The part number is 56026779 and is a Crown Automotive part. Has anyone else had any issues lile this?

I checked the part number on the parts list over at XJJeeps.com so I can't see it being the wrong one.

Thanks

BlueRidgeMark

Check the part number on the part against the part number you ordered. It could be as simple as a mistake in filling your order. Crown is usually decent stuff, but they could have blown it on this part.

EZEARL

Or does the new one's threads match up with the old one's? Shouldn't have to but you may have to chase the threads with a die on the new one.

boxburn

I've checked the part number on the diagram, order number and received item and all match.

As for a die, we tried but can't find a match to the original sensor. What I've found online says it should be a 1/8 NPT but that does not fit.

dave1123

The Crown could be metric pipe and you're right, it won't fit. The amount to taper and the thread lead are different. At my job, we were supposed to run some injection molds from Italy and our water fittings for cooling didn't fit. 1/2 NPT screwed in a couple of threads but leaked. We told them we had to rethread all the water fittings to NPT or get their fittings. They weren't thrilled that we had to rethread their molds.

I think you'd be better off getting a sensor that fits, even if you have to get it shipped from the US.

boxburn

The problem with that is where do I get one that I know fits? This one should have fit and is an imported part itself. I don't mind having to get bits shipped over, it's all part of owning an old American car for some parts.

I rang the company I bought it from and they said it should be correct so they have emailed Crown to confirm for me. Looking closely at it, the end of the threads don't look great and the metal isn't cut to a flat finish like the original one so it could very well be a bad unit. Also looking at various images online the end should be flat. I'll know more tomorrow from them, the issue is, this was their last one in stock.

boxburn

It looks like there's a different part number for European models, from Crowns website regarding the one I bought:

However, when I search for the part number I found, the sensor looks nothing like the one I have and I can't find anything on Crowns website saying for EU models. Oh the joys.

Edit: Upon more searching, the only EU ones that look like mine take a ring terminal on the end whereas mine takes a single pin connector. All of the EU ones that don't look like mine also take a ring terminal so could just be a different body design.

EZEARL

Does your XJ have a light or gauge? Below are links to sending units. Only one is for the European model. It's for a gauge and is the only one that has the stud electrical connection. Nothing mentioned about thread differences though.

https://www.rockauto.com/en/catalog/...+/+switch,4588

https://www.rockauto.com/en/moreinfo...180268&jsn=536

boxburn

I have a gauge but my original doesn't have the stud, it has the connector like the 56026779 unit.

EZEARL

An alternate number from the Rock Auto part turned up other brands of sensors.

https://www.yoyopart.com/oem/1422572...-56026781.html

boxburn

Thanks for the links. All of the cross reference parts also have the threaded end instead of the harness plug. I do think the issue is with a manufacturing defect at this point. I'll report back when the supplier has gotten back to me.

EZEARL

Ok.

I've run in to a lot of cross references but some have no pics.

boxburn

That's what I found too. Thank you for taking the time to have a look.

fb97xj1

Rockauto shows part # 56026779, but comes up as 56026779AB. Mopar. It is not with the rest of the sensors. You have to use the Part Number Search. Many OEM parts only come up using that.

https://www.rockauto.com/en/parts/mo...re+sensor,8660

boxburn

So now the conclusion.

• Crown had confirmed that I have the correct sensor.
• I had ordered a T-piece and an oil pressure switch to add an oil light in.

I was able to screw the Crown sensor into the T-piece a little bit although not as easily as the switch did. Using a triangle file I cut the leading threads of the Crown sensor down a bit and was able to screw it in further. I was happy with how far and tight it screwed in and was then able to fit both sensors to the Jeep. I was happy to try and force it into the T-piece and work with it in my hands but not try and force it onto the engine.

My oil pressure now reads higher than it did, it used to show 3 bar on cold start or while over 1500rpm then around 2 bar or so on hot idle. Now it seems to show 4.2 on cold start and 3.5 on hot idle. I'll have to verify these readings with a manual gauge as there's quite a difference. I want to be sure my new sensor isn't giving a bad reading after the threading on issues I've had so far.

Thank you to all who tried to help me out.