Oil Pressure Sensor

DocB · **Posted:** Mon Mar 26, 2018 2:41 am

Do you think this would be a correct/good place to install an oil pressure sensor?
The silver colored hex drive plug that sits above the longitudal pertruding hump.
If so, what do you think the threads are in the block?
For orientation, right, rear of block, behind and below turbo.

papaindigo · **Posted:** Mon Mar 26, 2018 9:33 am

Yes. Go to http://colorado4wheel.com/manuals/Jeep/KJ/ and download my tech tips PDF. Scroll down thru the bookmarks for "DIY installation of oil pressure gauge in main oil gallery" it's all there. You might want to get a bit of appropriate hose for a remote mount of the pressure sensor so you can relocate it to the top of the engine instead of directly to the block where vibration might be an issue.

TURBO-DIESEL-FREAK · **Joined:** Sat Apr 17, 2010 3:29 pm **Posts:** 1167

Posting reply to see the progress of this project.

GordnadoCRD · **Posted:** Mon Mar 26, 2018 7:03 pm

DocB wrote:

For orientation, right, rear of block, behind and below turbo.

Wow, this picture PERFECTLY illustrates the importance of adding thermal protection around the turbo oil supply line.
Exhaust temps in this area range from 400F to over 1000F depending on engine speed and load.
That bare steel line soaks up that heat and transfers it to the oil flowing through it.
I believe this is the main cause of turbo failure on these engines.
The oil being delivered to lube and cool the turbo, is being heated well past it's capacity to perform, before it ever reaches the turbo bearings.

Solution: Something like this, as well as Cudos to DocB for having his downpipe wrapped!.
https://www.summitracing.com/parts/hsp-204009?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-heatshield-products&gclid=Cj0KCQjwtOLVBRCZARIsADPLtJ12a1OOkQN3tIGVCspDxYjRDOkwT-4hwUbKmrzJaIRDRNQ0C5ttKPIaAuBxEALw_wcB

DocB · **Posted:** Mon Mar 26, 2018 8:42 pm

Great idea on wrapping the turbo oil supply line. Never thought of that. Will do that now that I'm in here this deep.
I will look for something that is split so that it can be installed without disconnecting the line.
Brought the Jeep in and put it on the lift for a few projects.
This job just gets deeper and deeper. Before you know it I'll be looking at the crankshaft sitting on the bench.
BTW-just wrapped the turbo downpipe. Been wanting to do this for a while, like about 150K ago.

flash7210 · **Posted:** Mon Mar 26, 2018 8:55 pm

FYI.
Your egr crossover pipe is missing the clamp that holds it tight against the exhaust manifold.

GordnadoCRD · **Posted:** Mon Mar 26, 2018 9:13 pm

DocB wrote:

Great idea on wrapping the turbo oil supply line. Never thought of that. Will do that now that I'm in here this deep.
I will look for something that is split so that it can be installed without disconnecting the line.
Brought the Jeep in and put it on the lift for a few projects.
This job just gets deeper and deeper. Before you know it I'll be looking at the crankshaft sitting on the bench.
BTW-just wrapped the turbo downpipe. Been wanting to do this for a while, like about 150K ago.

That is actually how I did mine. I used the same wrap I used on the downpipe, and fastened around the whole thing with hog nose clips. (upholstery type.)
I started at the banjo bolt, and once I fastened the lead end, I just kept sliding it along, wrapping and clipping as I went, about 1cm at a time.
It has stayed put for 7000+ miles so far. I wish I had realized this tubular stuff was available before I did all that though.
https://lmr.com/item/LRS-1001/Hog-Ring-And-Plier-Kit?utm_source=google-shopping&utm_medium=comparison-shopping&utm_campaign=google-shopping-v2&adpos=1o2&scid=scplpLRS-1001&sc_intid=LRS-1001&gclid=Cj0KCQjwtOLVBRCZARIsADPLtJ1bsopSw8WG5yyDNM6DZW3J6s5H4fs0D3p5nN1PxkGB08ZvvAWOpPoaAqwqEALw_wcB

DocB · **Posted:** Wed Mar 28, 2018 12:15 am

flash7210 wrote:

FYI.
Your egr crossover pipe is missing the clamp that holds it tight against the exhaust manifold.

Yes, I know. Took it off and was going to move the pipe for better access to the trans dipstick bolt. Will reinstall shortly.
I wound up dropping the trans 2.5" and accessing the bolt from the rear over the trans with long extensions.
Only way for me to reasonably get at the bolt. But it was still hard on religion.

DocB · **Posted:** Wed Mar 28, 2018 12:21 am

Question: Why couldn't I just take out the plug, put a hex on the external, drill and tap for 1/8 NPTF where the hex drive is and reinstall the plug and its copper washer and screw the sensor into it?

Do you see anything wrong with this approach?

GordnadoCRD · **Posted:** Wed Mar 28, 2018 12:23 am

DocB wrote:

Only way for me to reasonably get at the bolt. But it was still hard on religion.

Is that a vote for a disconnected soundproofed shop? :furious:

rancherman · **Posted:** Wed Mar 28, 2018 12:21 pm

DocB wrote:

Question: Why couldn't I just take out the plug, put a hex on the external, drill and tap for 1/8 NPTF where the hex drive is and reinstall the plug and its copper washer and screw the sensor into it?

Do you see anything wrong with this approach?

I don't know the OD of that plug, so do some math! Make sure there will be enough 'meat' left over after tapping. You don't want to put in a plug that has paper thin walls! I don't know the OD of that plug, but I do know you need to use a 'r' bit (.339) drill. The material removed in the cutting of the threads makes it even thinner.
Keep in mind, when you make your 'hex', it's going to reduce the amount of contact area with the sealing washer. may or may not be an issue.
You could just screw the drilled and tapped plug (no hex) onto the sensor, snugly, and then use the sensor itself as the 'drive' to torque the whole assembly into the block. A drop of thread lock on the plug-to-block threads should help, and help retain the plug if you need to replace just the sensor.
This is how I plan on installing a stand alone OP sensor. ^^^

papaindigo · **Posted:** Wed Mar 28, 2018 1:51 pm

Sigh - or you could just read the PDF document I provided the link too; assume that those of us who have actually done this have something to offer and reasons why we did what we did; and benefit from our experience or not. Your choice. If we had to do it over we would spend about $15 + shipping with McMaster-Carr for the pretapped plug and anything else needed depending on your choice of pressure sending unit + maybe $20 from GlowShift for the remote mount hose. Otherwise feel free to reinvent the wheel.

Unless you have free access to a machine shop drilling and taping for the appropriate pipe thread is not cheap, been there done that, and I don't even want to think about how one would add flats to the stock plug. By the way if you looked at the side on image of that plug in my PDF you will note it has almost no shoulder and IIRC is slightly recessed when screwed in place so flats won't likely do any good.

As for using the sending unit as a "driver" to install the plug all I can say is good luck.

Double sigh.

rancherman · **Posted:** Wed Mar 28, 2018 5:38 pm

papaindigo wrote:

Sigh - or you could just read the PDF document I provided the link too; assume that those of us who have actually done this have something to offer and reasons why we did what we did; and benefit from our experience or not. Your choice. If we had to do it over we would spend about $15 + shipping with McMaster-Carr for the pretapped plug and anything else needed depending on your choice of pressure sending unit + maybe $20 from GlowShift for the remote mount hose. Otherwise feel free to reinvent the wheel.

Unless you have free access to a machine shop drilling and taping for the appropriate pipe thread is not cheap, been there done that, and I don't even want to think about how one would add flats to the stock plug. By the way if you looked at the side on image of that plug in my PDF you will note it has almost no shoulder and IIRC is slightly recessed when screwed in place so flats won't likely do any good.

As for using the sending unit as a "driver" to install the plug all I can say is good luck.

Double sigh.

I only answered the man's question. He wanted to know, so I told him. Cripes.
When he goes to the tool store, and see's what a tap and proper bit will cost, it's his decision to continue.. or bail. Some of us already have these tools in hand.. so why not?
Edit; i'll concede, I have been looking at mine 'outside' the vehicle, for 2 weeks now. It makes a difference when the block isn't bolted up to anything, or anything is bolted to it! :roll:

LOL

papaindigo · **Posted:** Wed Mar 28, 2018 6:14 pm

Understood.

DocB · **Posted:** Wed Mar 28, 2018 10:44 pm

papa, thanks for the link to the PDF and I did read it. Good stuff.
Just asking because I do have the tap and drill, and access to a machine shop.
Not trying to reinvent the wheel, I just like to keep my sensors and their center of mass as close to the block as possible, to mitigate the effects of vibrations from the engine.
Would like to try to avoid all kinds of accessory plumbing coming out of the plug. KISS works best for me with my luck, or lack thereof.
I would not attempt to seat the plug by using the sensor to wrench on. Definitely agree this is a wrong approach.
The plug has not yet been removed and the reason I am asking about it first, and trying to learn beforehand. I will remove it this weekend and inspect the copper seat area and if there is enough room to mill a hex on the external of the OEM plug. Probably will have the McMaster-Carr adaptor on standby just in case. But again, it is 1/4 NPT which will have to be bushed down to 1/8 NPT for my sensor and moves it away from the block.
Just a little bit about myself and how I like to work, and that I am no expert, and am still learning and brainstorming to maybe come up with a better solution, or not.
For those of you that have actually done this before and have posted your experience and reasons for doing it that way, thanks again, your advice greatly appreciated!

DocB · **Posted:** Fri Mar 30, 2018 1:02 am

Plumbing Possibilities: (not screwed together tight yet and sensor is 1/8" NPTF)
1/4" Pipe

1/8" Pipe

Oil Pressure Sensor

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