I decided to add these gauges, in order to have better monitoring of my engine after chipping.

I see these instruments as an insurance, and they can be the difference between going or not to the dealership and getting embarrassed: “… I blew up the turbo. I’m sure it was due to lack of oil lubrication, either I have coke oil in the lines or it didn’t have enough pressure. By the way, this baby is chipped. Do you have any problem with that?…” I hope that you see my point.

This text describes how I did my install, it might require either different parts or procedures based on your own situation. Also, I do not have any training or certification related to this install, so you are doing at your own risk.

I would like to explain a couple of things before we start.

All 1.8 Turbo B5's use a warning sensor that sends current after 1500 rpm requiring a specific pressure range (1.1 - 1.7 Bar). If the control system does not detect this pressure above the set rpm, the alarm goes off. Therefore, I could not use the <7 PSI warning contact on the dual pressure sensor to replace the original. As a matter of fact, I did use the warning contact to switch on/off a led, so now I do have a low-pressure sensor. The only other oil sensor in this engine is a low level one in the oil pan.

I installed the oil temperature sender on the oil filter casing that has an extra accessing point, used by the A4 stock oil temperature sensor. I also believe that this temperature reading is more accurate than the oil pan, since the oil is coming from the engine, just before the oil-water cooling system. There are other options, and I am describing them too.

I also chose VDO because the font matches with the Passat’s panel.

Parts:

. VDO Vision Oil Pressure Gauge, 150 PSI (VDO part # 350 108).

            You can use an 80 PSI (part # 350 104) or 100 PSI (part # 350 106) gauge instead. The pressure in my chipped 1.8T never goes beyond 72 PSI. A lower pressure gauge will give you a better reading. Just keep in mind that if you decide to race your B5, you might need a better oil pump, and your gauge/sensor combo will not be the correct one.

.VDO Oil Dual Pressure Sender, 150 PSI and warning light below 7 PSI, M10X1 (part # 360 023).

           This  can be tricky. There are several options of senders. You can have it single at 150 PSI, or dual with different warning light settings. I got this one by mistake. I thought that I could replace the stock warning light with the sender’s contact. Check  www.vdona.com for other options.

.VDO Vision Oil Temperature Gauge, 300F (part # 310 106)

          This one will do it nicely. I never saw my temperature going beyond 212F.

.VDO Oil Temperature  Sender, 300F, M10X1 (part # 323 423)

           This also requires a decision. The one I used is located on the oil filter casing. The other option is either drill a hole in your oil pan and screw in the sensor or replace the oil plug with one that has the sensor in it. I personally do not like these options. The first one can introduce a point of leakage, and for a clean job, it will require draining the oil pan, drill the hole, then put everything back. Otherwise metal pieces can go inside the pan when you are drilling the hole. The second puts the burden of  reinstalling at every oil change. Do you trust the technician changing the oil? The wire can break; the contact can get dirty, or else.

.VDO T-Adapter, M10X1 (part # 240 850)

          I only could find it at Rapid Parts (www.rapidparts.com). There are other options, but unless you like nightmares you definitely need to use this one.

. Piggyback Fuse unit

. One 15 Amp fuse

. A supply of 16 Gauge wires, preferable with different colors. I used:  “+” red, “-“ blue, pressure sender  green, temperature sender black, warning light blue.

. A supply of female spade connectors (11 units used),  ring connectors (3 units), splitters (5 units) for 16 gauge wire.

Optional parts:

. Red Led and 1K Ohm resistor. If you bought a dual pressure sensor.

. Fuel line hose (4’ long) to use as conduit.

. Passat DIN radio trim (part # 1HO857231A01C). I have an MY2000 B5, so thanks to another fellow B5’er suggestion, I removed the storage box under the radio, then moved the radio down. I bought this piece ($3), and drilled 2” holes. It snaps perfectly  in the radio spot and it matches the dashboard trim 100%. I only suggest you doing a template using  a piece of wood first. Drilling the holes in the plastic can be very tricky, and you do not want another trip to the dealership to order the same part. Another option is to add a-column pods from Autometer (www.autometer.com). They have for B5, I called them to check. I use it first, but it looks too “ricey”, if you know what I mean, no offense here. You can also use dash pods from VDO, the problem is how to get the wires to the pod without either drilling the dashboard or  using a conduit that will certainly clutter the dashboard. The last option is using mounting cups from VDO. It presents the same problems of the dash pods. Good Luck!!!

Tools:

. Drill. drill bits, and a 2” hole drill bit(optional).

. Phillips Screw driver

. 30T torx screw driver

. Ratchet

. 8 mm socket (for the panel screws)

. 24mm wrench (to remove the stock pressure sensor)

. 24mm socket (to install the stock pressure sensor)

. Pliers

. Wire striper

. Piercing tool or a big nail.

Step 1 Decisions

First decide which model of gauges and appropriate sensors you want, and the location. Then buy the parts that you need.

I am assuming from now on that you will do exactly the way I did it.

Step 2 Under the hood

I suggest that you set aside at least 2 hours to do the install, as long as you are mechanically inclined and have all the parts. Adjust the time to your own level. I am sure a professional can do it in less than 2 hours. I could not.

It is also advisable that you do this work when the engine is cold.

2.1 Open the hood (if you have a problem with this step, stop here!).

2.2 Remove the screws that hold the coolant expansions tank, then unplug the coolant level sensor. You are now able to twist the tank towards the engine. This will give you a better access to where you will be installing the sensors.

2.3 Locate the stock pressure sensor. It is behind the engine, 2/3 towards the top, above to the left the oil filter casing. Then disconnect the plug.

2.4 Use the 22mm wrench to remove this sensor. You should do it carefully, not to break the plastic connector or it will be a $15 dollar trip to the dealership. Then clean the area with a paper towel, you will later be checking for leakage.

2.5 Place the “T” in the stock pressure sensor hole, screw it carefully not to damage the thread. I used a pair of pliers for the final twist. Also make sure the lateral inlet of the “T” is pointing to the opposite side (180 degrees)

2.6 Coming from the top of the engine, screw in the stock sensor. First by hand as much as you can then tight it with the 22 socket. This is the fun part. I had to literally lay down on top of the engine, put he socket first, than the ratchet. The ratchet could do only one click, so it took me 30 minutes to tight it properly. You might find a better way, and I will gladly add it to these instructions. Then plug the stock sensor socket back on.

2.7 Remove the nuts from the VDO pressure sender and screw it in the back of the “T”.  I used my hand, and a pair of pliers for the last turn. Make sure you know which terminal is the warning, and which is the pressure sensor.

2.8 Get 2 sections of 16 gauge wires (5’ long each), preferable different colors, and crimp a ring connector on each one. Then put them in the sensor contacts, and screw in the nuts. Do not over tight, it already has a pressure washer, and you can break it by putting too much torque.

2.9 On the oil filter casing, you will find a torx screw facing the front. This is the place a stock oil temperature sensor is placed (A4 ‘s have it).  Replace the screw with the oil temperature sensor. I had mine so tight that I use a pipe as extension (my torx set is socket type). Then get another section of wire, crimp a female spade connector on it, and plug in the sensor. The round head of the sensor is the actual spade, so you have to use an open female spade connector (non-insulated) and keep the open part of the connector downward.

2.10 Get the wires to the ECU box, through the engine compartment. You have to use caution to avoid that the wires touch any hot part inside the engine. I used a black fuel hose as conduit, and passed the wires inside it.

2.11 Open the ECU box (you can find good instructions at http://www.audiworld.com/faq/faq_engine/faq66.shtml) At the  front part of the ECU box there is a nipple, pierce it for each wire to pass very tight. I used a nail, then push each wire through with a very small Phillips screwdriver. You will be able to see the pedals from inside the box. If you have a problem seeing them, put a source of light next to the pedals. Pass the wires through the ECU box.

Attention, the ECU is a computer board, always ground yourself, touch a big metal piece for example, before getting close to it.

3. Inside work

3.1 Remove the fuse box cover, unscrew the black screws (8 mm) that hold the left lower part of the panel (where the light switch is), and the ones close to the pedal. Then pry out very carefully the panel towards the driver seat.

3.2 Next to the headlight switch there is a rheostat that dims the panel lights, hook a split and section of wire up to the light blue wire. This is the source of  “+” current for the gauges lights. Use an appropriate color (I used red). Make sure that the headlights are switched off, before the hook up. You do not want surprises, like a melting panel, do you?

3.2 Use the Piggyback fuse unit to replace the fuse of the rear wiper fuse (#27 ). This is your “+” source  for the instruments. Then crimp a section of wire (I used red) to the butt connector that comes with the piggyback unit. Again, make sure that you removed the key. It actually feeds current only when you turn the key, but precaution is warranted.

3.3 Crimp a ring terminal to a section of wire (blue). Remove one of the screws that bolt on the metal plate next to the fuse box. Place the ring terminal and put the bolt back on. This is your source of “-“ current for lighting and instrumentation.

3.4 At this point you should have all the sources ready. Sensors (pressure, warning, temperature) coming from the engine compartment (3 wires), “+” current for lighting and instruments (2 wires), and the “-” source. Pass these wires to the place where you want to install. In my case, I tied them up, and pass them inside the dashboard up to the center console. I had to pry open the right part of the lower panel after removing some more 8mm screws.

3.5 Cut the sensor wires to its final length and crimp female spade connectors to the sensor wires.

3.6 The warning light wire will be soldered to the 1K Ohm resistor, and then to the one of the led terminals.

3.7 Use splitters to multiply the “+” and “-“ sources, and crimp female spade terminals to the end of the wires.

4. Finishing

4.1 If you decide to do what I have done, then now is time to cut the DIN radio trim to fit the gauges. I bought a thin piece of wood, cut it to the length of the trim piece, and drilled 2” holes at proportional distances. It is a lot easier to mark and cut the wood. The best way to cut, is mark the central points, drill a  small leading hole, then use the 2” drill. Once the template is ready, measure it again to make sure the holes are in the right place.

4.2 Put the template on top of the trim piece, and clamp them together. You must be careful not to break the wood template. Do not drill all the way  with the 2” drill all the way, just put it in place, and make a quick run. The center should be marked now by the center drill of the 2” hole drill bit. Then use a small drill bit to go through the plastic. After that use the 2” drill bit, be gentle, there is not much room between the edges of the hole and the trim edge.

4.3 Drill a hole next to the pressure gauge to fit the led. Make sure you use a drill bit a little smaller that the led, so it will snap in, otherwise you will have to glue it in place.

4.4 Pass the appropriate wire through the rings that screw in the gauges, then through the holes,  and attach the connectors to the right male spade terminals, and solder a  “-“ wire end to the other led terminal.

4.5 Screw carefully the rings to the gauges and pop in the led.

5. The moment of truth.

5.1 Switch the lights on. The lights in the gauges should be on and if you dim the panel, it should work for them too. I used red replacement bulbs to match the panel, but the red diffuser that come with the gauge work well too.

5.2 Turn your key to the accessories stage. At this point the instruments should come to the 0 mark, and the led should be on (less than 7 PSI in the system). The coolant sensor bell will go off, since it is disconnected at this time.  You probably are use to the gas and windshield washer alarms, so you are safe.

5.3 If you have not set your car on fire, then turn the engine on. At this point the led should turn it off, the oil pressure should be around 70 PSI (it happens when the engine is cold). The temperature will climb very slowly, so give a few minutes before you can see it.

5.4 Check the “T” area and the oil casing for any leaking. Oil is really good on finding a spot to leak. If you spot a leaking you can tight the connection a little bit more or use Teflon tape. I do not like to use the tape because it can act as an insulator, influencing the measurements.

5.5 If everything is working fine, pop in the trim piece, put the panel back together, close the ECU box, put the coolant sensor back, screw in the coolant tank, and have fun.

6. The next day

6.1 Check couple of times for leaking. Remember, you have a plastic panel under the engine, so a small leaking can take days before the oil hit the ground. I am a little meticulous, so I cleaned with a paper towel before and after installing the “T” and the temperature sensor. Then I use a cotton swab to check for leaking.

6.2 These are my readings for pressure:

       6.2.1 When the engine is cold, the pressure goes to around 70 PSI for a while, then after few minutes it goes to 30 PSI, finally when the engine reaches the working temperature it seats around 10 PSI.

       6.2.2 When driving and the engine already reached the working temperature, it responds to your left foot. The more you use the throttle the more pressure in the system, around 30 PSI cruising at 70 mph.

6.3 Temperature readings are simpler. It takes some time to see a movement on  the needle, then at working temperature it goes to just below 210 F. If you play with your left foot, then the needle goes to just above 210 F. I never saw it different, but I have not pushed the engine for more than couple of minutes (no Autobahns where I live).

I hope that your install turns out good, and if you still have questions post at the forum or email me at passat_ts@hotmail .com.  I will gladly answer them.