Faulty oil pressure sender (I hope)

[jjonez]

I posted this in the 2-door section, but I would really appreciate feedback from the VG30E guys as well. Thanks!

 

 

Today I was driving my 87 pathy down the highway and I noticed my oil pressure light was on. Weirdly though my oil pressure gauge was showing what it normally does.

 

Some backstory: When I bought the truck about 18 months ago the oil pressure gauge wasn't working properly. The light was never on after startup, but oil pressure would read zero at idle and only like 10 on the highway. On cold starts it would climb to about 30 until warmed up then drop back down. I replaced the sending unit and things improved but still not quite spec. Now on cold starts pressure will go to the middle (45 I think?), then when warm at idle it will drop to zero/sometimes slightly above zero, then when cruising at about 3000 rpm it will be at 30.

 

I figured since just changing the sending unit improved the pressure reading, that maybe the old sender or the port that it screws into is partially clogged or there's some issue with the wiring. So I assumed that my actual oil pressure was fine. In any case, kind of weird that the light would come on even though the pressure gauge was "normal". To be on the safe side I had it towed 50 miles back home.

 

My initial plan now is to check the pressure with a mechanical tester and get a new sender on there. But I was hoping to get some insight or suggestions from you guys as well. Clogged oil pickup maybe? It's worth noting that the truck doesn't consume any oil, and the dipstick today showed full and the oil looked pretty clean (I think about 1500 miles since the last change). Also there wasn't much discernible valvetrain noise (this is usually a symptom of low pressure right?)

 

Last thing, I happened to snap a picture of the passenger side valve train the other day when I changed the valve covers. Besides a little bit of sludge in areas where the oil pools (i.e. bolt heads), I'd say things look pretty good right? I read somewhere that sludge here can indicate a clogged pickup.

 

 

Thanks for all the help guys! She'll stay parked until I can figure this out.

[adamzan]

That looks great under there. I'm betting you're just having @!*% luck with senders. Did you replace it with an OE one? Good idea to test with a mechanical gauge. If all is well after that, run it without worry. Mine has 275k miles on it (roughly) and still has great oil pressure.

[Cuong Nguyen]

I'm with Adamzan on this. Clean engine there!

 

Sent from my SAMSUNG-SM-N920A using Tapatalk

[jjonez]

Thanks guys! The first replacement sensor I got was standard motor products from rock auto. This time I ordered an OEM which was only like $20 more and will hopefully make the difference.

[Citron]

I bought a standard motor products reverse switch from rock auto and it looks like it has been used. I would stay away from standard products.

[jjonez]

Now that you mention it I got it at a discount as a wholesaler closeout, don't know if that's telling. I can't remember if the box looked opened or not. The only alternative on rockauto is from Airtex/Wells. My order for the OEM sender got cancelled saying it's a discontinued part so I tried another website today. They already billed me which hopefully is a good sign, but I'm not getting my hopes too high yet...

[Citron]

Mine had crud in the threads and around the connector. It looked new, but returned, like someone was shotgunning parts and returned the things that didn't fix the problem. Mine was also wholesaler closeout.

[jjonez]

Ah that sucks. Guess it's good I didn't buy that wholesale exedy clutch that I saw a while back haha.

 

I'm 0 for 2 on purchasing an OEM sender. Any suggestions on where I could get ahold of one of these? I feel like I'll get the same luck at most nissan parts websites I order from.

[Citron]

Your in the NW right? I have had good luck with Olympia Nissan. Nissanparts.cc is their online store.

[jjonez]

I'm in SoCal, but I went on their website and no dice I think my only chance at getting one is from a junkyard or private sale. I stopped by a Nissan dealer today and the guy said even the "master warehouse" in Tennessee doesn't have it, and that all the OEM parts websites are sort of linked in some way to Nissan's inventory. I'll probably just get the Airtex, no reason they shouldn't all work the same other than just bad luck I hope.

[adamzan]

I've had the best luck with beck/arnley aftermarket electronics.

[jjonez]

Great news! I tested the oil pressure with a kit from harbor freight and it was great. 62 psi on a cold start, 11 at hot idle, 54 at 3250 rpm. The kit came with a booklet listing the proper pressures for different makes and engines. It said 53 psi at 3200 rpm so the engine is basically new!

 

As adamzan said, turns out I was just having @!*% luck with the senders. I wasn't able to find an OEM sender, and B/A doesn't sell one for trucks with a gauge so I installed the A/W one and it made a big difference. The light is no longer on and now the dash gauge reads about 15 psi at hot idle and is right in the middle at 45 on the freeway. The gauge still doesn't seem to want to go past the halfway point no matter what and there's still a delay in needle movement. I've heard the latter is common though and I'm still very happy with the improvement.

 

Thanks for all the suggestions guys!

Edited November 19, 2017 by jjonez

[adamzan]

A lot of those aftermarket parts are junk. It isn't uncommon for me to have to go through 2 or 3 before I get a good one. I always try and get OE, if possible.