The other threads on this seem to be all over the map and things aren't getting clarified all that well.

So here's my end-all thread on installing an oil pressure gauge on a 2.4L LD9.

First off, here's what I've found so far. Please correct or add to any of this. Eventually we should have something for the FAQ here.

The best location for the pressure line or sender is behind the block, near the bottom just behind the timing chain cover. The second pic here has it labeled. You should not remove your stock sender since the ECU needs it and may throw a code if it's not working properly.





[quote=97cavie24ls(JDM cav sedan™)]all you have to do is plug the existing plug out , and use the adaptor in the kit with the pressure gauge

Does anyone know what thread size this hole is? Some people may not have the proper adapter so this would be useful to know.

What I want to know now is what happens when you pull that plug out? Will oil come pouring out? Do you need a pan under the car while doing this? Do you have to get the new plug in as soon as possible? If using a mechanical gauge, should the other end already be hooked up to the gauge?

When using a mechanical gauge, do you need to bleed air out of the line? Is there some method of doing this? Will it throw the readings off if you don't?

Finally, running wires or lines through the firewall is easiest if you go through the giant white/grey grommet on the driver's side just above where the pedals are. Get your head down in there and you can't miss it. I believe you can just poke small holes in it to run them through. Is there anything further people need to know about that? Is it easily torn or destroyed or anything?

That's all I've got for now. Any tips, answers, or suggestions?

Attachments

oilwater.jpg (59k)

Kevin,
From what I knwo there are 2 easy spots.

Intake side cam tower and a plug ABOVE the water pump NOT next to it...

One will give you head pressure while the other one is block pressure.

the standard oil fitting in the auto meter (and most other companies) will screw right into the location

ive never had to bleed the line on a mechanical gauge , once you shut the motor off the oil sucks back into the oil passage , not all of it does


the 1 you have circled in the 2nd pic i believe is a oil passage also


you can see the copper colored block heater in the water pump housing , most do not have that , so you could use it for a coolant temp sensor

or you can make up some kinda T-fitting in the stock housing , but keep in mind its a plastic and has no ground if your electric gauge needs a ground

Karo (Car Customs) wrote:Kevin,
From what I knwo there are 2 easy spots.

Intake side cam tower and a plug ABOVE the water pump NOT next to it...

One will give you head pressure while the other one is block pressure.

Eric said in another thread not to plug it into the cam tower. Is there a reason for this?

Has anyone got a pic of this plug above the water pump? Is it somehow different from the one Eric used, shown in the pic above? Functionally different or easier to get to?

The one marked WATER ? is a water jacket. The one BEHIND the water pump is an oil passage BUT you will have to take the pipe off the thermostat housing to access it and get the fittings and line in the block. The one marked OIL is where the timing chain tensioner fits into the block and is easier to get to. It might have a little oil in the hole but not much.





"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"

kevin , you can use the 1 in the head , but requires more parts because you have to keep the stock oil pressure sender

the 1 in the block is alot closer to the mains , and will see the pressure drop , a few mila-seconds before the cam tower 1 would , and with the way the 2.4 are know to eat rod bearings , the sooner you can catch it the better


are you sure gary ? the circle is over what looks like the oil passage

the arrow is actually on the coolant line


im going off memory here , but i belive its the oil passage and the water passage is above it , if you look where the water pump housing goes into the block it is above the hump for that passage

I used the same location as the stock sender. I did min year ago Doug Messick help me. If you get some of those copper fittings with the correct size like i did you can make a T from the OEM sending location and have your OEM and Aftermarket in the same location. I can try and take a picture of what i am talking about and post it tonight, no codes had it that way for about 5 years now..


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"You can please some of the people some of the time but you can't please all the people'
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The one circled above the steel water pump line is definetly a water jacket. There is another pipe plug down and to the right of that one (right behind the Black pipe going down from the thermostat housing) that is an oil passage. That is the one I used for my gauge because I had the motor out of the car and it was easy to get to at that point. Now if I have a leak in the line to the gauge I'll have to drain the coolant and pull the water line loose to to get to the fittings.





"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"

To do it on the block is more accurate. Yes. Harder to do. Everyone I have seen on a 2.4 was on the head. I have mine on the head, WITHOUT the stock sender in there. It WILL NOT throw a code. Been this way since I have had the car. My 97 Z24 same way. So for the purpose of this FAQ putting it on the head without the stock sender in there will work just fine. It would all depend on what the person doing it wants to do. Personally I think it is pointless to have the stock sender on there with a T. Do not like the way it looks. I will try and get a picture for you guys of mine as well.

found my picture I was looking for. This is without a stock sender in place.

john317 wrote:The one marked OIL is where the timing chain tensioner fits into the block and is easier to get to. It might have a little oil in the hole but not much.

Ok, so taking that plug out in my garage isn't going to make a big mess then? Does it only fill with oil when it's pressurized?

John Higgins wrote:Personally I think it is pointless to have the stock sender on there with a T. Do not like the way it looks. I will try and get a picture for you guys of mine as well.

What does the ECM actually do with the info it gets from the stock sender? If it senses a drop in pressure, does it go into limp mode or anything? Does it just turn on the CEL and let the engine go ahead and destroy itself?

Doesn't it interpret the lack of a reading from the stock sensor as a complete loss of pressure?

it should only dribble out oil , oil is only under pressure when running


from what i remember the pcm is susposed to shut the fuel pump off with loss of oil pressure , to shut the motor off , example a roll over


gary ill have to check the block ive got at home , i coulda sworn that 1 was for oil , but could be wrong

Wild Weasel wrote:

john317 wrote:The one marked OIL is where the timing chain tensioner fits into the block and is easier to get to. It might have a little oil in the hole but not much.

Ok, so taking that plug out in my garage isn't going to make a big mess then? Does it only fill with oil when it's pressurized?

John Higgins wrote:Personally I think it is pointless to have the stock sender on there with a T. Do not like the way it looks. I will try and get a picture for you guys of mine as well.

What does the ECM actually do with the info it gets from the stock sender? If it senses a drop in pressure, does it go into limp mode or anything? Does it just turn on the CEL and let the engine go ahead and destroy itself?

Doesn't it interpret the lack of a reading from the stock sensor as a complete loss of pressure?

No it does not. Once on my 97 z24 I was losing oil (never found out why) and got down to 2qts. My manual gauge was all over the place so I took it easy and go over to check my oil. Car still ran normal. It will allow it to detroy it's self. You know how they call them idiot lights. The sender is just for the light. If you go in with a scanner there is no info for oil pressure in the computer.

Guys,

I don't know what the big fuss is about the stock oil pressure sensor location. Out of two cars (my 96 Z and 2000 Z), I have not had any codes what-so-ever (yes, I scan my cars and don't just rely on my CEL).

The only car I know of that actually has a problem with the sensor being disconnected is the 1995 Js. OBD1 needs the sensor to start the car.

Give a shot Kevin. Disconnect the sensor to see what happens.


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ive used the tech 2 scanner , and it only shows wether it has pressure or not

if gm changed the sensor to not shut the motor off , they messed up if you ask me

You shouldn't make any bigger mess than Lenko changing his oil in the parking lot of the Super 8...





"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"

Here are the directions I followed when I made my adapter.

Autometer Oil Pressure A-Pillar Gauge Installation

(This installation is for the 2.4L LD9 engine)
(My installation was performed on a '96 Cavalier Z24)


Parts Required

Brass Adapters

1 1/8" male to 1/4" male
1 1/4" male to 1/8" male
1 45 degree angle w/ 1/8" fittings
1 1/8" T-fitting w/ 1 male and 2 female ends
1 bottle of lock tite
1 Autometer Oil Pressure Sensor
10 ft each: 18 gauge wire, or close to it. Red, Black, and Blue or Purple
Electrical crimp fittings for electrical connections
Electrical tape, solder, splices, where needed (personal preference on this one)



Electrical Setup

The gauge requires 3 wires to be run before the gauge is functional.

Run the black wire down the A-pillar to a good ground. If you can't find a good ground, then screw a machine screw into the body behind the plastic sill plate cover, and attach the wire to that screw.

Run the red wire from the gauge with the black wire, and splice the red wire into the ignition wire. This wire might be hard to find, but it is purple, and I recommend that you make sure that it is a ignition wire by testing it w/ a voltmeter, or test light. It should have almost no voltage when the car is off, and it should read 12 volts when the car is on.

Run the signal wire from the back of the gauge, which is purple, along w/ the other 2 wires down the A-pillar. Push the wire through the large rubber grommet in the driver side foot well, which is located above and to the left of the clutch pedal, or brake pedal.

Pull this wire through from the engine bay, and make sure that you have about 3-4 feet of wire hanging out.

The 2 short wires on the back of the gauge are for the light inside the gauge. Attach the black one to the ground terminal on the gauge, and the other wire to the ignition wire terminal on the gauge.

The gauge should light up when the car is turned on, or when the key is in the accessory position, but it shouldn't read anything just yet.

The electrical setup is now finished.


Mechanical Setup


You will need a few adapters in order to install the Autometer Oil Pressure Sending Unit, and still keep your factory sensor. That means that your oil pressure warning light on your dash is still functional.

The adapters you want to use are going to be Brass, and most auto stores (Pepboys, Auto Zone, Advanced Auto Parts...) have a box of different kinds behind the counter. You don't have to use the exact same fittings as I used to get the job done, but here is the list of Brass adapters I used for the oil pressure sensor:

Brass Adapters

1 1/8" male to 1/4" male
1 1/4" male to 1/8" male
1 45 degree angle w/ 1/8" fittings
1 1/8" T-fitting w/ 1 male and 2 female ends

Female
|
|
T-Fitting: Male----------Female


You also want to use lock tite to seal the fittings. Use the lock tite on all connections, but only cover 2-3 threads of each fitting. You want it to seal the joint, but you don't want to use too much, because you may want to remove it someday.

The OEM oil pressure sensor is located on the driver side of the front cam housing. It is screwed in slanted, between the two cams. You should be able to locate it easily by locating the connector to the IDI cover, and looking almost directly under that, and between the cams.

Disconnect the IDI cover's wire harness, and the connector to the OEM oil pressure sensor.

Place a few paper towels under and around the OEM oil pressure sensor. A little oil may leak out, but this shouldn't be a problem.

Remove the factory sensor by using Channel Locks. It shouldn't be too tight.

Install the 1/8" male to 1/4" male fitting into the hole where the OEM sensor was.

Screw the T fitting into the adapter, which is now on the cam housing, and tighten it. Make sure that the middle female end of the T fitting faces directly up, and that it is tight.

Screw the 1/4" male to 1/8" male adapter onto the OEM sensor.

Screw the sensor, with adapter, into the side fitting of the T adapter, the one that faces the driver side fender, and tighten.

Screw the 45 degree angle fitting onto the middle, or top, opening on the T fitting. Make sure the opening of the 45 degree adapter makes a 90 degree angle to the driver side fender.

Screw the Autometer oil pressure sensor into the opening on the 45 degree angle adapter.

Run the sensor wire from the grommet over to the Autometer oil pressure sensor, and attach it to the terminal on the sensor.

Here is how the setup should look:

Assembled Fittings:


Autometer Oil sensor
/---/
/ /
| |
|---|
|---|
Cam ---||- |----| |-| ---||-
Housing || | | || Original Oil
--- ||- |--------|-----||- sensor



Installation is now complete


Check the sensor

The sensor should light up when the ignition is on, and it should make a reading as soon as the engine starts.

Make sure that none of the fittings are leaking. This should be checked somewhat often, until you are sure that it isn't leaking. You should also check this periodically.

The oil pressure should read somewhere between 75-100 psi when the engine is still cold. This is because the cold oil is thick.

The oil pressure should be around 25 psi at a warm idle.

The oil pressure should be around 25-60 psi under war conditions, and when the rpms are high, 2-3000+ rpms.

You should be able to see the oil pressure rise as the rpms rise.


Now, go play with your new gauge. Your done.





Jason
99 Z24
#25 to register on JBO!!
Racers Edge
Johnny Mack Turbo Systems
Engineered Performance

Are there any arguments AGAINST using the plugged, unused port that Eric recommends? That seems to be both the best and most convenient solution, assuming you can get to it. How tough it is to get to when the engine is still in the car?

i like my spot


and i copied it from karo

I don't see any problems on getting the pressure from there. I will have to check my spare block to see what size hole that is

Another option is when you do the secret cam swap, put in an 2.3 exhaust tower. The 2.3's have the oil sending unit on the exhaust cam, not the intake cam like the 2.4's




Jason
99 Z24
#25 to register on JBO!!
Racers Edge
Johnny Mack Turbo Systems
Engineered Performance

Wild Weasel wrote:Are there any arguments AGAINST using the plugged, unused port that Eric recommends? That seems to be both the best and most convenient solution, assuming you can get to it. How tough it is to get to when the engine is still in the car?

Nothing wrong with using that spot. I just think since it is for a FAQ you should list all usable spots. truely unless I had my motor out I would not do the one on the back. The cam tower is easy to get to, and reads the same. Why not list both allow people to pick what way they won't. If you do not they will still post because people are going to tell them oh you can do it there. I bet if there was a poll more people do it on the cam tower. Like some people like to say if it is good enough for GM should be good enough for us.

Right, and really, it's by far the easier spot to connect to so people should definitely be aware of it.

On my 2.4 motor there is a sensor right above my oil filter.. Could that be used for the oil pressur gauge? Im assuming because thats where my sensor is on my 2.2L that I used for my gauge.









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WHITECAVY wrote:On my 2.4 motor there is a sensor right above my oil filter.. Could that be used for the oil pressur gauge? Im assuming because thats where my sensor is on my 2.2L that I used for my gauge.

Not sure what sensor you are talking about above the oil filter. i will have to look tomorrow. The places you want to use for a oil pressure gauge are the ones talked about in this thread.

Kelly Jones wrote:

WHITECAVY wrote:On my 2.4 motor there is a sensor right above my oil filter.. Could that be used for the oil pressur gauge? Im assuming because thats where my sensor is on my 2.2L that I used for my gauge.

Not sure what sensor you are talking about above the oil filter. i will have to look tomorrow. The places you want to use for a oil pressure gauge are the ones talked about in this thread.

yea pull that one out....... its your crank position sensor......

I've got mine in the cam tower......... and my stock one in the HO exhaust tower......

The stock sensor is just for the OIL light on the dash...... it grounds out when you loose oil pressure, and it triggers the light....... thats it. (unless OBD-1 like said above) if you unplug it, nothing happens






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