[RESOLVED]Thread Pitch of stock Oil Pressure Sending Unit

[Zmann42087]

This past weekend I attempted to install my Autometer Oil Pressure gauge and AMS oil pressure remote sending unit. Unfortunately, it didn't go so well..

The remote sending unit I bought is designed/sold for EVOs VIII/IX. I called AMS inquiring if this would also fit my car and the sales guy said, "yeah, sure it will fit." So I bought the sending unit and tried to install it this weekend but when I did it cracked my oil filter housing! Turns out the AMS remote sending unit is slightly bigger than the stock sending unit.

I'm now trying to find out what the size (thread, pitch, etc.) of the stock oil pressure sending unit is so I can purchase the right size fitting for my remote sending unit. Does anybody know the size of this thing? I'd greatly appreciate the help.

Thanks in advance guys..

 

[blcknspo0ln]

I don't know what the evo's use, but our oil filter housings use a BSP thread. If I remember correctly it is a 1/8-27NPT and the BSP that is used on our cars is a 28 pitch thread.

 

[turbosax2]

I wonder if this kit has the right size fitting?

 

[Zmann42087]

Well, I just got off the phone with AMS' tech department. They still maintain that the fitting they sell in their kit should work. The guy I talked to said the stock fittings are BPT (just like you said Tom) but apparently they just use a 3/8" fitting and it works.

When I went to install it, I only slightly torqued it in so as not to crack the housing. I started up the car and it was leaking just a little bit. So I shut it off, and tightened it a little bit more.. still had leaks though. I tightened it a third time and start back up the car. Thats when I found oil pouring out from underneath the car. Yep, the housing cracked.

I figured that it was the fitting as they appear to be different sizes. But I don't know.. maybe it is the right size.

I have to go through the trouble of putting on a whole new oil filter housing, so I just want to make sure I get the right size fitting so this doesn't happen again.

 

[BoostedinSoFla]

1/8 Bspt.

 

[Grizzly Racing]

1/8" NPT (national pipe thread)

Try using a little bit of teflon tape next time to get a good seal.

 

[Zmann42087]

Alright, I called AMS again and talked to a different guy. I think I've got it figured out now. Below is a picture of the AMS remote sending unit I purchased.

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The fitting on the left side (the side with the 90° bend) is the one that attaches to the oil filter housing. As you can see, its definitely too big to be 1/8 bpt (infact it is 3/8). Of course I noticed this when I got it so I took off the large 3/8 fitting to find a smaller fitting that looks like it would fit in the stock oil pressure sending unit location. This is what I threaded into the stock sending unit location that consequently cracked the oil filter housing.

You're probably wondering why the hell I did this. My line of thinking was that the large 3/8 fitting was included for applications where the turbo oil feed line was relocated to the head. In which case the 3/8 fitting would be used to thread into the stock turbo oil feed location on the oil filter housing.

Turns out I was completely wrong.. the 3/8 fitting is in fact supposed to be used. If you go out to your car and look just below the stock turbo oil feed location, you'll see there is a large 3/8 plug with a hex/allen-key center. This is apparently where you are supposed to locate the remote sending unit. Just take out the plug stick the 3/8 fitting in. I had no clue really.. everyone I talked to and every thread I've read says to locate the new sending unit for the aftermarket gauge in place of the stock "idiot" light sensor sending unit.

Does this all sound correct, guys? The right place to thread in the remote sending unit is where that hex-plug is located just below the stock turbo oil feed line?

 

[blcknspo0ln]

yes you are right. There are several years that come with that allen plug port used for the oil feed line to the turbo (read: see defiant's infamous dummy light pic.) On my old 97 tsi that's where the oil was taken from. So since that port is readily useable, you can retain all of your factory sensors and put the remote line there. Since I've found out first hand that the idiot sensor does SHIT for you, I ran a 1/8-27NPT tap through the factory 1/8BSPT port and will just be running a line from there. Well, that and the fact that my allen plug is freakin stuck in the OFH so I can't use it anyway.

 

[turbosax2]

You could get a 1/8" BSPT to 1/8" NPT adapter like this, but then you have one extra adapter between that adapter and the ss line. I like using as few adapters as possible. I'm still searching for an adapter with 2 male sides.

 

[BoostedinSoFla]

1/8" NPT (national pipe thread)

Try using a little bit of teflon tape next time to get a good seal.

It's BSPT/BPT (british pipe thread) and not NPT (national pipe thread). The whole teflon tape thing is also debatable/arguable but I won't get into that.

 

[BoostedinSoFla]

The right place to thread in the remote sending unit is where that hex-plug is located just below the stock turbo oil feed line?

Yes, you are correct.

 

[blcknspo0ln]

It's BSPT/BPT (british pipe thread) and not NPT (national pipe thread). The whole teflon tape thing is also debatable/arguable but I won't get into that.

I are uses the teflon on everything

 

[T is for TURBO]

I are uses the teflon on everything

Teflon FTW!

Yeah, I would just go with the BPT to NPT adapter... that is, if you can find one... or are willing to order one and pay a $10 shipping cost. (don't try autozone, they don't have them... I tried)

 

[BoostedinSoFla]

I have that same Autometer adapter (Part number 2269). I almost ordered it from Jegs/Summit but found out my local speed shop sells anything Autometer so they ordered it and I only paid $9.

 

[turbosax2]

Instead of Teflon tape, use products like these:

http://www.permatex.com/products/Au...ts/auto_Permatex_Thread_Sealant_with_PTFE.htm
http://www.permatex.com/products/Au..._Permatex_High_Temperature_Thread_Sealant.htm
http://www.permatex.com/products/Au..._Permatex_High_Performance_Thread_Sealant.htm

 

[blcknspo0ln]

I have to share! I was doing a little research and noticed that the summit racing remote line is just a simple -4an ss line, so I went outside and dug through some spare parts and found an old -4an oil feed line that I had from my non-bb 50 trim days. I thought I'd try it and the 1/8NPT screws right in! Does anyone know what pitch/thread the -4an ss lines come with? I've never looked into it, but it for sure feels right so I will be using this line to remote mount my oil pressure sensor along with using the high temp sealant Eric recommended. It's handy to have a bottle or two of this stuff when teflon can't prevail, eh?

 

[Zmann42087]

I have another question guys.. I've got the cracked oil filter housing out and have replaced it with a new one, but before I thread the AMS sending unit into the new housing, I decided to test it in the old one first. One cracked housing is enough.

So I removed the hex plug below the stock oil feed line location on the cracked oil filter housing and tried to thread the AMS sending unit in. Unfortunately, it still doesn't seem to fit properly. I can get it started but it gets tight way to quickly. The threads are not the same.

Basically I'm running into the same problem I was when I tried to install this remote sending unit in the stock sending unit location. I believe the threads in the housing are 3/8 BSPT female and the AMS remote sending unit is 3/8 NPT male. Its just not going to work.

What I need is either a 3/8 BSPT male to 1/8 NPT female adapter fitting or 3/8 BSPT male to -3AN male fitting. I've been searching for a good 20 minutes but I've had no luck finding either. If anybody knows where I can find one, please let me know.

I guess if nothing else, I could follow Tom's lead and run a 3/8 NPT thread tap through the 3/8 BSPT hex plug port in my new oil filter housing, but I'd prefer to avoid this route if possible.


EDIT: By George, I think I've got it... 42 Draft Designs: EVO Oil Pressure Adapter

 

[turbosax2]

For anyone else interested, I emailed Jay Racing about their kit and it includes these fittings:
1/8" BSPT male X 1/8" NPT male
3/8" BSPT male x 1/8" NPT male

Remote Oil Pressure Sender Kit [RPS1] - $40.00 : Jay Racing

 

[Zmann42087]

After browsing 42 Draft Design's sight a little more, I came across this fitting.. Lancer EVO 1/8" NPT Oil Temp Adaptor. Its the same 3/8 BSPT male to 1/8 NPT female adapter I need but its $4 cheaper than the one I posted above because it excludes the little 45° fitting needed to clear the subframe on the EVO. I won't need that 45 degree fitting so I'd prefer not to pay for it. Just wanted to throw this out there in case anyone else has the AMS remote mounting kit.

For everyone else, save yourself some time, money, & headaches and just buy the Jay Racing remote sending unit in the first place. Its what I should have done.

 

[Defiant]

"Pipe thread" is different from other threads in that it's designed to not only connect and fasten, but to seal against fluid leaks as well. Do not use Teflon on the joints on an engine. You don't need the cut-off threads of tape in your oiling nor fuel system. Use a small amount of Permatex non-hardening.

 

[blcknspo0ln]

For everyone else, save yourself some time, money, & headaches and just buy the Jay Racing remote sending unit in the first place. Its what I should have done.

Sounds like a whole bunch of mess. I just tapped the OFH to 1/8-27NPT with a tap I got, reused an old -4an oil feed line and bought 2 of these bad boys. Total extra cost was like $10 to go to a remote line