Printable Version of Topic

Posted by: McMark Jul 29 2009, 01:50 PM

I had to do some research on the oil temp sender setup as well as researching how to integrate an aftermarket VDO setup. I found that our info here was sorely lacking. So I decided to put everything I found in one place.

Stock System:

Sender
Markings on the hex portion of the sender itself.
1. VDO - manufacturer
2. 6-24v - operating voltage
3. 200*C - upper temp limit, this sender feeds a gauge that peaks at 400*
4. 801/7/2 - ?????
5. Made in Germany - location of production
6. 12.72 - date of production (changes, Dec 1972 in this case)

Threads are 14mm x 1.5. This has been improperly quoted in the past. I just measured it myself.

These senders operate in a range of 3000 to 1000 ohms (pretty sure on this, my sample measures 2500 at room temp).


Mount Plate
The stock oil temp sensor mount is commonly referred to as the Taco Plate. This name originated from its tendency to bend in the middle when overtightened, like a taco. The stock system includes a sender cover plate which protects the components, and (IMHO) is mainly there to protect the wire from being unplugged accidentally. The mount plate itself uses a large red o-ring to seal to the engine case. The sender cover uses a circular paper gasket.

The plate/cover mounting bolts at 6mm x 1.0 and are 10mm long. The bolts are sealed by using two copper crush gaskets.


Connecting Wire
Wire is 18g Green jacket with a black stripe. 40" overall length, female spade connectors on both ends. Green wire is available at most auto parts stores and a Sharpie can be used to make the black stripe. The wire is routed through a rubber grommet in the sender cover plate

The wire is attached to the motor at three points by sheet metal brackets which are crimped onto the wire.
1. The first connector is attached to the sender cover plate. From here the wire routes above the motor mounts to #2.
2. The second connector attaches to the lower mount bolt for the oil filter console.
3. The third connector attaches to the lower oil cooler to fan housing bolt.

#--3"---|-------------11"--------------|-------8"--------|---------------15"----------#



Gauge
The stock center console gauge came in two setups. They do not have any numeric indication of oil temperature, but rather have a red section at the top of the range which indicates when the motor oil is getting too hot. The red section on the 'early' gauges is larger than on the 'later' gauges. AFAIK, the readout of both gauges is exactly the same, and Porsche redesigned the gauge because owners were nervous/cautious/concerned about the normal operating temperature was 'too close' to the red on the early gauges. These gauges have a 60mm mounting diameter.

An uncommon third gauge replaced the blinking brake warning light in the left hand combo gauge. This sender came in 'silver button' early type and the late 'blank' style. On these gauges the large red warning light was moved to a small red light in the center of the gauge.

VDO Components

Gauge
Upgrading to a VDO oil temp gauge is beneficial because of the numeric representation of oil temp. There are quite a few options for these gauges, but most commonly used are the Cockpit versions which look quite similar to the stock center console gauges. When using these gauges in a stock center console, some modification has to be made to account for the smaller OD of the VDO gauge, since these gauges feature a 52mm mounting diameter. I forget what size, but a section of black ABS pipe can be used to take up the difference perfectly.


Sender
VDO senders use a 150*C/300*F standard peak temp and are therefore not interchangeable with stock senders. VDO senders operate in a range of 10 - 180 ohms. VDO makes a sender that is compatible with the stock mounting plate, part number: 323-055D.



There is more information out there, but that's all I have at this time. If you've got info to add, please do.

Posted by: Vacca Rabite Jul 29 2009, 02:20 PM

The VDO 2 1/16 oil temp gages sold now come with a different sender, with a short prong to measure temp. The threads are the same, and they will screw into the taco plate sender. I am not sure if using the smaller (2 1/16inch) gage with a long sender or using the stock gage with with the shorter sender will give you false readings.

Using the short sender allows bus owners (or folks that make an engine with a bus case) to mount the sender on the taco plate without machining the case for the longer sender.

Zach

Posted by: McMark Jul 29 2009, 02:33 PM

The new sender is 'stubby'. I added a picture of it to the original post, as well as a picture of the Cockpit gauge.

The stock gauge should not be used with the aftermarket sender.
The stock sender should not be used with the aftermarket gauge.

Posted by: marks914 Jul 29 2009, 02:45 PM

Yes, all of this is correct. You must use a matching sender for the gauge module. The new senders will not work. We can't even get the old styles form VDO anymore.

You need one of these to get your factory gauge to work again, correctly:
http://rides.webshots.com/photo/2117910870057582025hQwmLr

Posted by: Mark Henry Jul 29 2009, 02:51 PM

Excellent Info! Thanks Mark! and Zack too! Classic thread for sure.

Already paid off to one member...me!
I have a universel case and no cut out for temp sender. I was going to hog that puppy out, now looks like I don't have to. I'll order a sender very soon.

Should show how you have to notch the plug seat (shoulder) to get a CHT sender in. (edit) Sorry I guess that would be OT.

Posted by: markb Jul 29 2009, 05:20 PM

QUOTE(marks914 @ Jul 29 2009, 12:45 PM)

Posted by: orange914 Jul 29 2009, 06:49 PM

QUOTE(Mark Henry @ Jul 29 2009, 12:51 PM)

Posted by: marks914 Jul 29 2009, 06:53 PM

QUOTE(markb @ Jul 29 2009, 07:20 PM)

QUOTE(marks914 @ Jul 29 2009, 12:45 PM)

Yes, all of this is correct. You must use a matching sender for the gauge module. The new senders will not work. We can't even get the old styles form VDO anymore.

You need one of these to get your factory gauge to work again, correctly:
http://rides.webshots.com/photo/2117910870057582025hQwmLr

Hey Mark, what is the module part number, I can see the sender number & want to match it properly.

Posted by: markb Jul 29 2009, 11:20 PM

D@mn. One more thing to buy........

Posted by: orange914 Aug 10 2009, 10:17 PM

QUOTE(McMark @ Jul 29 2009, 12:50 PM)

Posted by: iamchappy Aug 10 2009, 10:30 PM

Anyone know where i can get an oil pressure module- scale-0-140. I sort of shorted mine out last weekend dinking around with my fuel gauge needle.

Posted by: zx-niner Aug 10 2009, 11:19 PM

Aw, great. After spending all weekend getting my Amco center console all wired up for the extra gauges and installed, now you tell me there is a better oil temperature gauge. Yep, one more thing to spend money on and spend another weekend re-doing.

Posted by: McMark Feb 27 2011, 11:29 PM

Picked up the latest issue of http://www.volksworld.com/magazine/3013/volksworld-magazine-february-2011.html (Feb 2011) and they did a side-by-side comparison of a few different oil temp gauge & senders. You can order the mag for all the details, but the conclusion is that nothing was less accurate than the VDO. Best accuracy was from a http://www.summitracing.com/parts/SGG-ST3310/.

IIRC, the margin of error on the VDO was 20+ degrees.

Posted by: Vacca Rabite Feb 28 2011, 09:40 AM

I use a Manley dipstick gauge as well as the modern VDO 2 1/16 gauge. The VDO always reads 10 degrees cooler then the dipstick thermometer (I usually check the two right after I take a hard drive, as soon as I shut down the car.)

Zach

Posted by: smveril Jan 20 2014, 03:59 PM

Since I installed the rebuilt motor after removing it 3 years ago, this is very helpful for the temp sender wiring routing and other details.

One thing I don't see is where the wire from the temperature sender is connected to the wiring harness. I see a single wire connector coming from the harness under the battery tray. Is this where it gets connected?

Posted by: Dave_Darling Jan 20 2014, 04:31 PM

Yes. Especially if the wire in that connector is green with a black stripe.

--DD

Posted by: jeffb Oct 27 2014, 03:13 PM

Does anyone have a photo or picture showing where T sensor 2 is located on a stock engine? I'm trying to install a Redline ECU and haven't been able to find it. I know what the Redline supplied sensor looks like.

Thanks

Posted by: Dave_Darling Oct 27 2014, 03:20 PM

"Temp Sensor II" is only used for the fuel injection system; not for any stock gauges. It sounds like this is the one that you want, though, since you're talking about aftermarket injection.

Look for your #3 spark plug wire. Near it, partly under the intake runner pipe for #3 cylinder, you'll find a hole with a single wire coming out of it. That wire comes from the Temp Sensor II (AKA the Cylinder Head Temp sensor), and plugs into a box connector on the fuel injection wiring harness.

The #3 cylinder is the one toward the right-rear of the car.

--DD