DIY: Oil temp and pressure sender install with modified banjo bolts
 

This is a very straightforward install. Please note that this does not cover any wiring of the senders, just the installation of the bolts. Also, I am in no way responsible for someone messing up their car. Your oil system is crucial, if your not competent then don't do this!!

Tools:
23mm open end spanner (wrench)
19mm socket and ratchet
Phillips head screw driver
oil drain pan
ramps (prefered) or jack stands
WHEEL CHOCKS

Materials:
2 modified banjo bolts
4 NEW crush washers
Teflon tape
2 quarts oil

If you want the information on were I got the bolts PM me, they have more made and ready to ship. I can say he was very helpful with the install, answering several questions I had.. In the rx8, there is little space available next to the firewall, making accessing the oil filter a pain. Adding an oil filter sandwich adapter makes this even more of an issue. With these modified banjo bolts the spacer is not needed. One replaces the banjo bolt attaching the oil cooler line to the front cover, and the other replaces the bolt securing the line to the cooler.

DIY:

First the oil temperature sender
1: put car on ramps and place wheel chocks behind rear wheels. I found ramps to work well; since I did not drain the oil I only lost 1/2 a quart since the front of the car was higher than the oil pan.

2: remove or pull back the underside of the drivers side splash guard to access the underside of the oil cooler. I just pulled mine back, there is not a need to remove the whole thing.

3: here you will need the 23mm spanner. The bolt closest to the drivers side goes to the next oil cooler, the one passenger side is coming from the front cover. My picture shows the one on the drivers side removed; you want to OTHER one, the passenger side. We want to measure the temps of the oil before it is cooled, as it comes out of the engine. The bolt is on there tight, but with enough force it will come off.

4:The shop already had my senders attached to the bolts; if yours are not now is the time to do it. Make sure you seal the threads on the senders with teflon tape or they will leak

5: DO NOT REUSE THE OLD CRUSH WASHERS!! Buy new ones. It will save you a huge headache and possible ruined day/week. they are $0.99 each at Napa, a cheap insurance.

6: put one new crush washer onto the bolt, slide it through the oil line, put another crush washer on, and bolt it to the oil cooler. The torque spec is 24 ftlbs. NOTE: do not use any sealant/tape here, thats what the crush washers are for. using these could result in a clogged oil line!!
Mod Edit: The factory service manual indicates that the torque spec is 39.4 to 50.5 ftlbs.
Thanks Pamion!

7: wipe off any remaining oil, but do not re-secure the splash guard.

Oil Pressure sender

1:this bolt is located directly under the A/c compressor. There is only one banjo bolt there, so there is no mistaking it. It is EITHER a 23mm or 19mm. I have seen it as either size, depending on the car. regardless of the head size, the shaft and threading of the new bolts fit perfect.

2: with a 19mm socket remove the old banjo bolt.

3: attach oil pressure sender to the new banjo bolt, being sure to apply teflon tape to the sender threading

4: put a new crush washer onto the new bolt, slide it through the oil line, place another new crush washer onto the bolt and bolt it to the front cover. the torque is 24 ftlbs. NOTE: do not use any sealant/tape here, thats what the crush washers are for. using these could result in a clogged oil line!!

5: check oil to ensure proper levels.

6: start car, check for leaks. if you have under/over tightened the bolts you could have leaks. If they are under tightened tighten them. If you over did it, replace the crush washers and try again.

7: Now you can reattach the splash guard your done!

interesting idea. The oil temp is very handy for us S2 owners that do not want to replace their pan drain plug with the temp sensor.

Nice write up. I had thought of doing this but using an oil filter adapter plate is just easier all around. But if you want more than one temp/pressure position then this is a great idea.

Once I had everything I needed this took me 30 minutes. I tried the oil filter adapter first, but I had a hard time getting it to not leak so said screw it and tossed it, lol

Weird, I have never had leaking issues with my cheapy Pro-sport adapter and it has been off an on at least a dozen times. You must work fast if you took your bumper off and replaced those bolt in 30 minutes :)

It has been said that i work fast :) there is no need to take off the bumper, just pull back the splash guard on that side. I don't have fog lights though, they may get in the way

That's not always a good thing depending on who said it :bootyshak

:lol:

I disagree completely

My RB filter plate is coming off soon to be replaced by the banjo bolts. It makes more sense on every level; ease of access to the sensors, more access around the oil filter due to it not being raised up, etc.. I don't have any leaking issue or anything like that, but it costs a lot more than the bolts if that matters.

this mod is a win all around, wish I had thought of it.


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Im surprised you didn't :) I did this about 5 years ago. Took then out when I went to the braided AN lines and connectors. They worked well. .. only thing you have to watch is that the sensors don't decrease the flow

I think he is really just PO'd that the best price I've seen so far is from his favorite vendor ;)

I figure while I'm updating to the AiM dash display I might as well straighten out some of the related stuff, had no real reason to mess with it otherwise, but will put it up FS with the the soon to be deleted RB ashtray gauge display. I know that my sensors won't protrude into the banjo bolt entrance/exit hole area.


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I agree now. Corksport sells a product for this very purpose (for the RX7 but it works on the 8) and it makes things nice and tidy. Shady got this product a couple of weeks back and it is a bit expensive (a bit more than what the crook charges) but it's simple and effective.

http://www.corksport.com/corksport-r...anjo-bolt.html

sure, if you don't mind paying double ...

Oil Sensor Banjo Bolts by RX-8 Performance | RX8Performance.com

I don't mind, the Corksport piece is a really nice machined piece and I don't have to worry about whether I will receive it or not.

http://www.corksport.com/images/deta...-Bolt-Main.jpg

like I said, your favorite vendor ... I was just going to drill & tap my own, but the ones from RX8Performance are cheap enough for me to not bother making the effort. I think I can chance $25 rather than immediately throwing it away ...

Looks like Sephitrask got his from there too, fwiw


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Let me second this point. Lightly screw in the sensor you have and make sure it doesn't significantly cut into the flow path. An adapter may be required to space it out.

Also, with my AEM 0-5v oil pressure sensor banjoed into the oil cooler feed line at the block, I'm not getting stable readings. I suspect that it's picking up pulses from the oil pump that it didn't see when mounted under the oil filter. Anyone else have this problem?

Later on, I'll try switching the pressure and temp sender (located on the entrance to the LHS oil cooler) to see if that fixes the problem. The downside it that due to the bulk of the pressure sensor, it's very close the the fender liner and a blown tire or chunk of road debris just might break off the sender.

The mod is especially nice for those using Series II oil filters. The taller filter + adapter makes it very hard to fit and remove. It will also prevent lifting the engine high enough to get to the engine mounts without lifting the whole car when the filter jams against the firewall. (Don't ask me how I discovered this. Yes, you can lift the whole front of the car with the Mazda OEM filter ....)



And, btw, I got the bolts from the vendor-who-shall-not-be-named, just fine.

This modification is just drilling and tapping a 1/8bsp hole in the end isn't it ? Or is there more to it ?

both the vendors listed so far have the sensor connection spaced out from the bolt head, just using different methods.

I suspect otherwise the sensor could protrude too far in and block the flow path through the bolt

Yes, but one spacing doesn't fit all. Sensors from different sources can have different spacing from their threads to the tip.

That's why it is really important to check :)

I had to remake one when I changed the sensor....the different threads on the new sensor made it screw in a lot further and it was blocking the flow

I am preparing to do this modification. This will actually be the first thing I have done to this car since I've owned it. I was going to use the adapter plate, that seems pretty common, then came across this thread. I will be getting the banjo bolts to install the sending units. Is this a good place to install a sensor for pressure as well? If not please indicate the best place for a sender. I am sourcing material now and would like to have everything I need before I turn the first screw. In addition have any of you used the Maxtow series of gauges MaxTow Truck Gauge Series ? I am leaning this way, but would like some feedback as to quality and more importantly accuracy if anyone has any information on them. It indicates they are for trucks, however they are the standard 52mm.

Thanks

Sephitrask: Thanks for posting this DIY, the idea of modified banjo bolts intrigued me to the point where I actually did do this. Thanks to these vendors

ProSport...Guages
RX8 Performance.com...Banjo Bolts
Racing Beat.com.com...Water temp sensor housing

I received all the parts two days after my order, with the exception of RX8 performance. Seems I ordered his last one so he had two make another production run to fill my order of 2. One quick call to Scott and he explained what had happened and all was well. They shipped when he said they would.

I would just like to add a note on the crush washers. Napa had them, but they were not labeled, just in a large bin of washers. Not feeling to good about this I went ahead and purchased them, but went to Mazda for the washers. Turns out they had them, and they were cheaper than NAPA? If you decide to do this mod the Mazda part number for the crush washers is 995621800 I just returned the NAPA ones. However they would have worked, I just prefer OE parts when I can source them and especially when they are cheaper.

The gauges are great, I chose the HALO series as they go black when not in use. It was tossup up between the Maxtow, but the color was not really working for me. If they change color they should emphasize that, otherwise I would have gone that route. After many years of ownership of this car, this is my first mod. I love being able to monitor these critical items. Thanks again to the OP for an awesome idea for the bolts.

Seems putting the Temp sensor on the oil filter Banjo Bolt would make more sense, as you would read the temp right out of the engine. instead of reading it after one of the coolers.

Has any one used a fitting to allow both pressure and temp to be attached to the oil cooler banjo bolt that is located on the motor?
i.e

You can use one on the front bolt...and one on the rear

Just make sure they don't block off flow..that wouldn't be good :(

Just did this today. Easy peasy and gets temps far quicker than when i had it reading from the pan drain hole.

Nice write up, now only if I can get motivated to put my banjo bolts on.

I am not sure why the S1 would have a different spec than the S2, but according to my shop manual you are off by at least 20ft/lbs here.

I did 24ftlbs as you stated here and had some leaking. Went back to the shop docs and saw that it is actually recommending between 40-50ftlbs.

Reference from S1 Workship Manual

Last week i did the banjo bolt mod for my prosport stepper motor pressure gauge and sensor. While i was racing my car over the weekend i noticed the needle was erratic. Even dropping to 0 and often going off the clock. Even on the strate. I assume this is not accurate as the back light flushed occasionally and other random stuff like that. Also the dummy pressure gauge in the cluster doesn't move . Has any one else seen erratic pressures when on track with the sensor on the front case banjo bolt? any idea if it is a dodgy sensor?


Posted from Rx8club.com App for Android

Make sure it's grounded well.....

I wouldn't think with normal oil level...on the straight that you will get pressure dropout

At 1.6G on race slicks in a long L corner....all bets are off :( (Cost me a front stat gear bearing)

Did you get the dry hump yet? :p:

Working on it :)

Did you use teflon tape? If so, you used too much. Senders ground through the threads as well as the ground lead (black wire). If your ground lead (black wire) has a resistive connection, and the threads aren't making good contact to the banjo bolt, it will cause your gauges to go bananas.

Haven't checked this thread in a long time, good to see other people doing it too!

Thanks for the correction. It has been so long since I made this that I don't remember were I got my number from, but I thought it was the FSM... guess not

It could be a bad ground, or the gauge may be toast. Makes me lean toward bad wiring if the light on the gauge is going on and off

thanks all. ill go over all the wiring and check everything


Posted from Rx8club.com App for Android

more than double. the Corksport only comes with one, not a pair.

just as an update, I ordered some of these from RX8 Performance on November 11 and still no banjo bolts. Sent an email to them and will follow up with a call.

That's been quite awhile,I had mine within a week of ordering

try calling him. I have been ordering these from him for almost a year now for my customers. I love them and most of his products. I know there was bad blood around in the past but nothing a quick call doesn't fix.

I torqued my bolts to 30lbs. and ALWAYS replace the crush washers with new ones and save yourself the headache later on.

I talked to him over the phone. He said something happened at the post office and they were lost. He is sending me another set but haven't gotten those yet. Hopefully i will finally have them this coming week.

Is there any preference on where to install the temp sensor and where to install the pressure? like is the temp going up at the cooler and pressure at the block?

I used the in line to the oil cooler for temps and the service port just above the rear plugs for the
pressure.

Paimon has a great DIY , check it out.


What i would like to know is, what are other series 2 owners using prosport gauges
getting for oil pressure #'s at idle when warm.

Checked the mail yesterday. Must have been delivered yesterday. Never got the one he sent before.

Hey guys,

First time poster on the US forum, pretty active on the aus forum down here. :wavey:

Been working out how to get these banjo bolts sorted and haven't found much info regarding the temp sensor for my defi gauges.

The temp sensor will be within the return line from the oil cooler.

The temp sensor sits quite deep within the oil line and was wondering if this is a bad thing and i should use a small nut on the thread and bring it out a bit?

Thanks:)

You will need to space it. What I have done is used a 1/4"NPT adapter and bored out the banjo bolt on the lathe and re tapped it. The sensor now sits away from the oil feed hole

Ahh ok, i ended up using 3 washers to bring it out of the feed hole.
Only slightly visible so hopefully it isn't impacting too much, car has been running fine since.
However I'm now paranoid watching temps haha

Hi Guys
Today I replaced my prosport oil pressure gauge with a 0-150 PSI Auto Meter mechanical gauge that takes the pressure form the front cover.
When I start the motor the pressure goes up to 150PSI and over a couple of min irt drops down to around 25-30 PSI.
But then when I free rev it, it will go from 30PSI up to 150PSI as the revs increase.
Any idea on why it does this?
Oil still cold and too thick?
Thermostats still closed on the coolers?

Cold oil = high pressure
Higher RPM = higher pressure

Shouldn't be 150 psi though...the relief should open before 95. Where do you have it plumbed?

It is plumbed into the banjo bolt on the front cover. so just after the pump. As the relief valve is on the other end of the oil system maybe when everything is cold it just backs up the pressure?
The car was just warming up in the garage so I could move it in the drive way so never had a chance to get hot but the water temp go up to the normal running temp.

my prosport gauge showed the same thing on start up. thought it may have been faulty.