DIY install a 4-in-1 meter

Oil Press, Oil Temp, Water Temp & Voltage

Monitoring the health of your car be it modified or stock is always a good thing. Most standard meter clusters from modern cars don't show whether your engine is having a problem until it's already reaching the extremities - too hot which usually means it's already overheating or the voltage goes too low (current) and you end up stranded in the middle of nowhere because the battery was unexpectedly drained, or too low oil levels, etc.

My car being modified and having had an overheating problem in the past, I thought it'd be best to have meters installed to monitor the health of the engine. Not wanting to have a entire row of meters, I opted for a 4-in-1 Depo meter. Choosing a meter is relatively important as there are a lot of meters out in the market. Some, replicas of famous brands which probably don't have a very long lifespan and some, their own brand with their own technology and ideas. Depo was one of the first few Taiwanese brands to come up with an all-in-one meter, which intrigued me as it met my criteria of not having a long row of meters on my dashboard, and it came with pretty decent quality sensors.

The kit was pretty straight forward. Wires, brackets, connectors, sensors and the meter itself were part of the kit. I bought my own water temperature sensor adaptor and oil filter sensor sandwich plate/adaptor, with that my kit was complete.

My car was due for a fluid change so I took this opportunity to install the meter with the fluids drained - specifically the engine oil and coolant.

Top tip : It's a good idea to have a spare water hose before you decide to chop up your existing one, just in case you mis-calculate and cut off too much of the water hose.

I opted to install the water temperature sensor on my top water hose connected to the radiator since the water exited from the block into the radiator through that hose. Just a note, before you buy the water temperature adaptor, find out the thickness of the hose. Not all hoses are the same diameter and get the one that's roughly the same diameter or ever-so-slightly smaller. Cut off the water hose, fit the adaptor and clamp it down with good clamps. The sensor is screwed into the adaptor with Locktite or PTFE tape (in my photo the sensor hasn't been connected yet. A bolt is in its place).

Adjust the adaptors position with consideration for the direction of the wiring.

Jack up your car and remove your oil filter. Just a note #2, most reputable brand oil sensor sandwich plates / adaptors have different center bolt threads which are easily interchangeable. Again, not all oil filter thread sizes are the same so find one that fits yours. Screw on the sandwich plate and install the sensor to one of the adaptors holes using Locktite or PTFE tape. Normally these adaptors/sandwich plates have more than 1 hole to allow for one than one sensor to be connected, do not remove the other sealed bolt unless you intend on installing another sensor there. When installing the sandwich plate, ensure the side that has the protruding rubber gasket is facing the oil sump, this will ensure an airtight seal to the oil sump/engine block. The smooth shiney 'face' (see picture 2) will then be facing outwards. Normally oil filters will have a rubber gasket surrounding the base so when you screw it on to the sandwich plate the gasket ensures an airtight seal.

In your engine bay - locate a suitable grommet on your firewall that can fit the wiring and gently slice the grommet so you can force the wiring through it.

Pull the wiring into the cabin and wire up the water temp and oil temp/pressure sensors. Be careful when routing the wiring, don't let it go anywhere near the extractor or any moving part of the engine.

If you don't have a choice, cable tie it carefully so the wires don't move and inadvertently cross paths with moving parts of the engine.

Find a suitable mounting spot for your meter and if necessary, get extra wires to extend the length of the wire if needed. Tap power from a suitable power source, in my case I tapped the cigarette lighter since I don't use that socket. Once everything is all wired up, turn on the ignition (no need to fire up the engine) and test whether the meter works or not!

Difficulty level : Medium
Time needed : A lot of hours. Add another 2 hours if you're a newbie
Satisfaction level : Priceless

- Izso