sidewayzgt

Hi All,

I am having a major conflict that I am having a heck of a time figuring out. I have a 2004 GTO LS1 that I am trying to install an oil pressure gauge in.

I have been reading in multiple forums that it is possible to tap into the oil sending unit in the back of the motor and use an adapter that Auto Meter makes (PN# 2268 LS Series Oil Pressure Sender Adapter) to make the threads compatible.

I have also been reading that the computer does not require the oil sending unit at all and will not throw a check engine light?

I do not want to drill and tap above the oil filter because it is to much work and I am not a mechanic lol.

Anyway, is this possible? If so, do I need to use a mechanical or electric gauge or will either one work? Your help is much appreciated!

Thank you

Mercier

iTrader: (15)

The computer does not care about the oil pressure in my LS1 application so I think you are safe there. BUT if you add that adapter and go with an aftermarket gauge(and correct; Autometer does sell the right adapter to get to 1/8" NPT like almost all aftermarket gauges), your factory gauge in the dash will be dead. Seems inconsequential but trust me--it will bother the crap out of you eventually!

I suggest you replace your oil cooler block-off plate with one that already has the 1/8" hole tapped in it. Two bolts and you can have both gauges working..leave the factory piece alone. IMO, the side of the motor right above the oil filter is far easier to get to than the factory location anyway.

On electric vs. mechanical, both will work. The mechanical takes any electrical funny-business out of the equation..but the electric also doesn't have a plastic or copper line with hot engine oil running all the way into the car. Pick your poison but properly installed, either will work just fine. Electric does have a larger footprint at the motor as there is a sending unit and the mechanical will just have a fitting to screw the pressure line on/in.

See this link for an example..two bolts and you have the fitting you need for the gauge:

http://wap.ebay.com/Pages/ViewItemPi...nbcol=0%7Cnull

From the factory you should have a block-off plate there with the two bolts but no hole in it. No drilling, tapping, or customizing. Bolt on and go. I think this is the better and easier option for you but it's not my car.

Good luck!

sidewayzgt

Thanks for the reply Mercier.

On my 2004 GTO there is no oil gauge that I can see? All that is shown on the bezel is fuel and water temperature. All that I have is an oil light that will come on if there is a problem. Very bad thinking for such a high performance car lol. Anyway, I would rather drill into the firewall then the tranny. I am also thinking electrical as well.

Are you sure that unplugging the factory oil sending unit will not throw a check engine light on this car? I am not sure if all LS1 motors and PCM's and ECM's are the same?

Thanks

MuhThugga

Keep the stock sending unit. At the minimum, the car will always give you a warning about low oil pressure at start-up.

There is a t-fitting you can buy to maintain the stock oil pressure sensor while having a secondary sending unit for an oil pressure gauge. Speedhut's Revolution gauge line, while more expensive, is more accurate and comes with a smaller sending unit that is about the size of the stock oil pressure sensor.

I would opt for the electric gauge so you don't have to worry about oil leaking in your cabin. That can get messy rather quickly.

sidewayzgt

Thanks for the reply MuhThugga,

I appreciate the suggestion and looked at the website you suggested but did not see that fitting.
If I tap the oil cooler block off plate will I lose any oil? I just changed it and it is expensive lol.
Is there enough room to T the pressure sender on the back of the block? If so, have you seen anybody make a T for them?

I think that I am going to go electric rather then mechanical.

Thanks!

Mercier

iTrader: (15)

If there is a warning light, I would still keep the factory sensor. The computer shouldn't flip out but the dash at least will have something ugly there. Aftermarket gauges can fail too, so the backup of the idiot light is good to have. Teeing off is definitely an option. To be clear, what I suggested is replacing a $15 part; taking the block off plate that is already there on all LS1 motors and replacing with one that already has the proper threads tapped into it. Look right above your oil filter. No drilling in the transmission..not quite sure where you got that idea. The wire would still run through the firewall. The block off plate is above the level of the oil pan so as long as you let the oil in the motor settle after running it(well, let it all cool down too so you don't burn yourself), a negligible amount of oil should come out..gravity takes almost all of it into the pan.

Good luck.

Mercier

iTrader: (15)

And easiest way to know if it will throw a code? Unplug the factory sensor and see what happens. That is free. Anyone with 3 teeth and a scan tool can clear the code for you, including Autozone or O'Reilly for free as well.

sidewayzgt

Thanks for clearing that up Mercier, you can probably tell by now that I am not a mechanic lol.. Anyway, it has to get done one way or another. Thank you very much for your help!

MuhThugga

The fitting itself isn't on the Speedhut website, but the Revolution series has a much more compact sender and a much more accurate gauge than the gauges that are offered in the kits that some vendors sell. Here is a link to give you some ideas on what to do to make for a much, much cleaner installation: http://www.ls2.com/forums/showthread...r-on-LS-Series

You will lose a little bit of oil removing the adapter plate to drill and tap. You won't lose all of it; just a fraction of a quart. Again, my preference would be to install a T-fitting at the sender location behind the intake. There is enough room to do it, it is a much cleaner look, and you don't have to worry about routing wires around headers.