Mechanical oil pressure gauge installation [Merged 1-8]

[DSM_23]

ok i have a mechanical oil pressure guage for my 91 tsi awd and i know the general area to tap into just not the exact place, all i know is, is that its near the oil filter, other than that i cant figure out what to tap into, so if somebody could help me out here it'd be nice, thanks

 

[NeMiZiS]

Cool, I'll have to grab those parts from my friends N/A!

Why would some one move the sensors around like that?WTF

Thanks for helping me out so fast!!!

 

[9!'clipseDOHC]

Why would some one move the sensors around like that?WTF

Because he didn't know what he was doing most likely.

Thanks for helping me out so fast!!!

Not a problem. Thanks for the rep points!

 

[NeMiZiS]

Because he didn't know what he was doing most likely.

Yea I should have known that, I mean there wasn't even a V-band clamp on the turbo when I got it.

Not a problem. Thanks for the rep points!

It's the least I could do!

 

[9!'clipseDOHC]

Yea I should have known that, I mean there wasn't even a V-band clamp on the turbo when I got it.

The joys of a new project. I've had my DSM for 8 years so by now all the kinks have been ironed out.

 

[Survivalism]

Ok hate to bring this back from the dead but i want to be sure before i have the shop make my hose.

I am installing a mechanical autolite gauge eliminating the stock pressure sender.

I will need a 1/8 npt --> 1/8 bpt adapter to thread into the OFH, now where im confused ( forgive my newbness ), what size AN hose do i need? What adapters need to be put on the end of each side of the hose? I am assuming 1/8 npt but i want to be sure.

Also 6 foot of hose will be enough correct?

Will i need anything else to plumb the gauge?

Thanks so much guys.

 

[ramsack]

-AN ARE the type of hose ends. There is no such thing as 1/8" NPT AN. Are you planning on running the gauge inside of the car?

 

[Survivalism]

-AN ARE the type of hose ends. There is no such thing as 1/8" NPT AN. Are you planning on running the gauge inside of the car?

Yes i am, so what size AN hose fits a 1/8 NPT? I am supremely confused.

or do i need a 1/8 bpt to -3 an adapter? If so how do i connect the hose to the gauge itself?

 

[ramsack]

-AN is not hose, it is a type of fitting. I would not mount that inside, and if you do, I would use something like 1/8" copper line and solder the crimp ferrules to the line.

 

[Survivalism]

-AN is not hose, it is a type of fitting. I would not mount that inside, and if you do, I would use something like 1/8" copper line and solder the crimp ferrules to the line.

From all my reading today AN hose is the safest way to avoid leakage i thought.

 

[TrystanGST]

I ran the copper line inside, and while routing it was tricky because of where I isntalled the gauge, it's leak free and easy to figure out.

 

[ramsack]

AN is not hose, it is a type of fitting. Leaking is not specific to types of fittings. Each have their own positives and negatives. AN was developed by the military, and is mainly for lasting after taking on and off many times, and to do it quickly. I would not put an oil pressure gauge in the cabin, but if I did, I would use solid 1/8" copper tubing and solder the brass ferrules to the line. It will use the same fittings that come with gauges, but use copper instead of plastic.

A trick to deal with running copper line is to attach it to the gauge end first, mount the gauge, and THEN do your bending down to the oil filter housing and trim the length. You definitely can't stuff the excess inside of the pillar like you can with plastic hose.

 

[Survivalism]

Ok sorry what i am still pretty sold on is the idea of using stainless braided teflon hose with fittings that screw onto the OFH where the sender went and then right onto the back of the gauge. I will be sealing it with teflon thread sealant after cleaning the threads with alcohol.

I dont think it will leak i just need to know what fittings and size hose i need.

 

[ramsack]

You don't seal AN threads with teflon tape, they seal by flares sitting together. Teflon tape isn't even for sealing...it's for allowing the threads of a TAPERED thread design to screw together easily so they can be tightened enough to deform and seal. You should sell yourself off of this and listen to people who know what they're talking about...

 

[99gst_racer]

From all my reading today AN hose is the safest way to avoid leakage i thought.

You're on the right track man. SS braided hose is the best method and is definitely a better idea than the nylon or copper tubing.

I've done what you're doing a few times and this is how I do it.

1) NPT and BSPT are extremely similar and only differ slightly in the thread pitch. You can easily "convert" BSPT thread to NPT thread with a tap. Remove the oil filter housing and carefully run a 1/8 NPT tap through the rear port. Keep it straight and slow and use some sort of lubricant such as tap magic or grease. Once finished, clean it throughly with brake cleaner and reinstall.

2) You'll then need a 'NPT to AN' adapter. More specifically, 1/8 NPT to -4 AN. It will look like this:

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Thread this into that rear port on the OFH and be sure to use teflon tape on the NPT side of the adapter fitting.

3) Connect your -4 AN line to that fitting and run it to your gauge. Chances are that your gauge will have a 1/8" NPT thread on the backside. You'll also need an adapter fitting for that as well. I always use this one:

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And you're all set. I have this same set-up on my Eclipse and it's been problem free for many years. I also had it on my old DD Talon and never an issue there either. The only difference with mine is that I ran a 'T' fitting to retain the factory sending unit. But the installation is essentially the same either way.

Here's the best pic I could find of my old Talon:

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[Survivalism]

You're on the right track man. SS braided hose is the best method and is definitely a better idea than the nylon or copper tubing.

I've done what you're doing a few times and this is how I do it.

1) NPT and BSPT are extremely similar and only differ slightly in the thread pitch. You can easily "convert" BSPT thread to NPT thread with a tap. Remove the oil filter housing and carefully run a 1/8 NPT tap through the rear port. Keep it straight and slow and use some sort of lubricant such as tap magic or grease. Once finished, clean it throughly with brake cleaner and reinstall.

2) You'll then need a 'NPT to AN' adapter. More specifically, 1/8 NPT to -4 AN. It will look like this:

You must be logged in to view this image or video.

Thread this into that rear port on the OFH and be sure to use teflon tape on the NPT side of the adapter fitting.

3) Connect your -4 AN line to that fitting and run it to your gauge. Chances are that your gauge will have a 1/8" NPT thread on the backside. You'll also need an adapter fitting for that as well. I always use this one:

You must be logged in to view this image or video.

And you're all set. I have this same set-up on my Eclipse and it's been problem free for many years. I also had it on my old DD Talon and never an issue there either. The only difference with mine is that I ran a 'T' fitting to retain the factory sending unit. But the installation is essentially the same either way.

Here's the best pic I could find of my old Talon:

You must be logged in to view this image or video.

Thank you so much! I was reading your posts in this thread from awhile back.

Makes so much more sense now! 6 Feet of hose will be enough right?

 

[ramsack]

Why is it "better" than copper tubing? Please explain. Choosing any certain fitting is just a matter of preference. If one is so adamant about -AN crap, then go with -3. You don't run garden hoses to gauges for a reason. Lines for reading pressures should be as small ID as possible.

 

[99gst_racer]

Thank you so much! I was reading your posts in this thread from awhile back.

Makes so much more sense now! 6 Feet of hose will be enough right?

No problem. After selling 10+ different brands of AN fittings over the past 8 years, I've come to be very familiar with them.

I mounted my gauge in the dash where the center vent used to be and 60" of hose was enough to reach there with a bit of slack.

Why is it "better" than copper tubing? Please explain.

Certainly. Nylon and copper tubing can easily kink and/or crack and cause an interior leak. And then there's the issue with ferules. It's common for people to overtighten them and result in a leaky connection.

I prefer SS braided, teflon-lined hose because it's strong, flexible, and more resiliant to damage and leaking. It's just a better and more user friendly connection. And when pumping 80 PSI of hot oil into the cabin, I'll take the route that offers the best possible chance at never having a leak.

If one is so adamant about -AN crap, then go with -3. You don't run garden hoses to gauges for a reason. Lines for reading pressures should be as small ID as possible.

-3 would work fine as well. It doesn't really matter much at all which size a person uses. We're talking about an I.D. difference of about .05" here. That less than the thickness of two sheets of paper. The one big difference is that there's typically a larger selection of available -4 AN stuff rather than -3. I went with -4 for that reason alone.

 

[ramsack]

I think the problem with ferrules is the user, and not installing them straight. If using copper, they tend to hold straight better than that plastic junk. Also because what junk Autometer ships tends to be a loose fit to the tubing. It should be difficult to slide a ferrule along a piece of tubing. Soldering a ferrule to a piece of copper tubing would make for a connection just as reliable as AN. AN is mainly superior in the quickness department. Other than that, everything is just preference. It's not a fact that it's any more superior at sealing or holding pressure.

 

[99gst_racer]

My biggest gripe with copper is that it's susceptible to kinking and requires more careful handling. It's a piece of soft copper solid mounted to a rocking and vibrating engine. Time will take it's toll. There's a few reports of leaking nylon and copper tubing on this forum alone.

And aside from a bit more cost, there really is zero downside to braided hose and AN fittings.

 

[ramsack]

Nylon, I will give you, is junk (for hot engine liquids), and should not have hot oil run through it. It's fine for boost.