426 Hemi

EDIT Go to post #29 and #270 for the latest and greatest Buick Sensor Mod. EDIT

Getting ta ta ta tired of pulling the intake to change the oil pressure sending unit----on a weekly basis. Yes, I'm torquing it properly.

Until such a time that GM, Standard, BorgWarner, Niehoff, Wells, or whoever else sells these things (all evidently made at the same manufacturer in Mexico), I'm going to do this.

Basically I'm going to relocate the sensor up top next to the left hand fuel rail-----a section of manual oil pressure gauge hose plumbed in to get there. You can buy this hose and fittings as a kit. Each end of the plastic hose has compression fittings ending up with 1/8th inch pipe thread ends.

I took one of the old sensors, drilled the center out and tapped it to 1/8th inch NPT. Then screwed in the hose's fitting. Very easy---looks good:






BTW did you ever see how frigging COMPLEX GM made this sensor? Inside there is a host of surface mount resistors, capacitors, and even an IC! Come on!






OK, ok the engine side is taken care of. Now for the sensor itself. I started out with a round chunk of billet. Hexed off the outside. Drilled one end and tapped it to the sensor's size---M16 X 1.5. Ok I cheated---I used a 5/8 -18 NF which is real close----and so is a 3/8 -18 NPT. And of course on the other end I tapped it to 1/8th inch NPT. Here's a pic of it---you'll also see it in the first picture also with the hose fitting installed. You'll see the plastic pressure hose looping down and around---leading to the back of the block.






And here is a shot of it in place. The connector reaches fine. I plan on securing it to the fuel rail and/or bracket.






Now if I had access to a CNC I'd probably make up a bunch of these----but my lathe is one step up from a wood working unit and my mill isn't much better. Took me half a day. Just how did we churn out thousands of P-38's back in the day before CNC---or even digital readouts??

Anyway I think there is a solution to making the adapter. And that would be the oil pressure sender from a 99 and newer Park Avenue. Looks to be the same unit with the same connector-----only it has what appears to be a 1/4th inch NPT end. In that case all you would need would be a double female to plumb to the oil line. I was just too cheap to order one of these sending units to find out.

Anyway this is my story and I'm sticking to it!

CorvetteTechInc

We don't do it to customers cars (unless they ask) but for our own cars we've just lifted the wiper cover (the 5 pins and wiper blades) and cut a hole in the plastic tray underneath (about 4-5 inches square). I've got a deep socket that I turned down to be thin enough to fit between the crossover plug bolt and the sensor. We were having some problems with sensors for a while also. With this method I can change a sensor in about 20-30 minutes.

I'm not saying it's an elequent solution, but I am saying it works and you can't see anything when you put the cover back on. Just mentioning it as another alternative.

white90conv

Very interesting posts. The complexity of the sender probably explains its unreliability - it is in a high temperature, high vibration region and circuit boards are probably not that reliable in such a situation.
Is there anywhere else on the engine that one can tap into the oil pressure?

oldschoolvette

two very good ideas

hotwheels57

I can't tell you how many times I've had that plastic hose break or melt in my cars since '66...that being said, a better alternative to a nice modification might be some -3 or -4 braided steel line with correct AN fittings/ends.

NEED FOR SPEED

That screws directly into where the original sensor was located.

426 Hemi

Good point. When ever I've used any of this in the past I've tried to guard against any chaffing or heat. Many production vehicles use this tubing--including about every aftermarket mechanical oil pressure gauge.

Ol'55

I can see how vibration would be an issue. I haven't had to do mine yet, and was thinking more "old school" thinking of the sensors with the large "dome" that houses a diaphragm, not realizing it as an electronic device. I think 426Hemi is on the right track! Thanks, good post.

cruisemon

The sensor is, in fact, VERY complex because it is a very sophisticated and accurate device. It has a device in it called a variable capacitance transducer. Pressure changes cause the capacitance to rise or fall. This capacitance change can be measured very accurately and is converted to a digital signal. Twenty five years ago something this technically adanced sold for $1100 and was the size of a coffee can.

$35 - $40 for a sensor like this is dirt cheap. I really wish someone could figure out what causes these puppies to leak.

Charlie

pcfred

Better patent it QUICK!!

N0TDADYS_98

I was already working on the paper work.... the patent belongs to the one who files first...

i kid.. this is a great idea... i just replaced mine for the first time.. but if i have to do it again... i'm going to do one of these mods.

426 Hemi

Ahhh, that's what I love about the internet---freely sharing ideas with pals across the globe that can be of use----and that can be ripped off and sold on e-bay.

All that I ask in return for using this idea is to refer to it as the "426 Hemi Mod".

rws.1

Actually the patent opportunity is gone unless a provisional patent filing was made before the posting ( which is a public disclosure) Once an idea has been publically disclosed it can no longer be patented..

Great idea.

madmatt9471

Very nice! If you can make some I will send the money as soon as possible!

Good write up! You the man!

Forunately I have not had to change mine yet.

Thanks,Matt

cruisemon

Not really. http://utrf.tennessee.edu/tto/docs/Impact_of_PD.PDF

In most other countries, the above is true. In the U.S., there is a one year grace period for filing from date of first public disclosure. I STRONGLY suggest that Hemi 426 act now to copyright the design and look at filing because this is sure to be a product that can be sold. Maybe not in the millions, but I suspect there are enough LS1 wrenchers out there to sell several thousand of them if the cost is reasonable. This thing will sell because you gotta KNOW GM isn't going to upgrade the failure propensity of the sensor.

I don't have a contact inside GM engineering and design any more. If anyone reading this does, or has a contact in another department that would be knowledgable, would you contact that person and see if they know anything about why these things fail?

Charlie

426 Hemi

Man we really need to check out the 99 and newer Park Avenue theory----because if that sensor is the same internally and if there is a pipe thread on fitting on it -------you could do this mod without having to make the billet adapter.

Anyone with access to a couple fittings and a tap could perform the mod. All available at any local Napa, Pep Boys, or whatever auto parts store.

litnrod

Not necessarily true, there is some statute about having one year from date of public disclosure to file, but I think this is US specific, no European patent for you. LOL

Sorry Charlie, didn't see your post above, before I posted my response. Glad I was right

426 Hemi

New intake gaskets in this morning---just got her back together.

And........the remote mod (426 Hemi Mod ) works like a champ!!! No leaks. Gauge works. Gonorrhea has cleared up.

Also it's cool to watch the oil flow through the tube. Flashback to my LavaLamp days.

Oh yeah, I also made a nice little clamp to hold the sender in place.

OK, now who's the guy who is going to order a ParkAvenue sender to see if that will work?

BiggieBoy

My hat is off to you What a fantastic idea...

SpeedyD

Great Idea!! Another idea instead of the plastic tubing would be a hardline. I would be worried abot the plastic melting and spewing oil everywhere. I know these lines are used in other sutuations but I just rather be safe than sorry!! Also, I do believe these fail becasue of heat and vibration, if the unit could be remoe mounted to the firewall thee would be a huge decrease in heat and vibration, just a thought!! Once again, great idea!! Dan