Testing M103 Oil pressure with a mechanical oil pressure gauge

In my last update, I had ruled out the sender unit when it came to the low oil pressure readings on my 300SE. My intention had been to take the car to a mechanic to test it on a mechanical oil pressure gauge. Two things changed that. Firstly, my area of Sydney went into lock down. Secondly, most mechanics are on holidays until after the new year. I therefore purchased my own mechanical oil pressure gauge off eBay.

I hooked up the gauge and sadly the results were much the same as the dashboard gauge. The mechanical oil pressure gauge […]

December 2020 Night Drive – Eastern Suburbs

The December night drive was the last official night drive of the year took us through the eastern suburbs. Yet again, the late night drive proved popular, as we had 25 registrations and a lot of cars show up on the day. The meeting point, at Bradfield Park (near Luna Park), under the Sydney Harbour bridge probably helped.

The meeting point also provided the opportunity for some nice photos with the bridge in the background. I took my 250SE which is nice to drive on warm summer nights with the top down.

There was a good range of cars from […]

M103 Oil pressure sender

A few weeks ago my 300SE started to show low oil pressure on the gauge. It happened all of a sudden while on a drive. At the time, I surmised that I had a dead M103 Oil pressure sender. They are apparently a common fault. I ordered a new one and fitted it today.

The M103 oil pressure sender can be found on the side of the oil filter housing at the back of the engine. Most of the threads you’ll find on the various forums are referred to the W124. Apparently on the W124 space is tight and it […]

My 560SEL’s selling dealer

My 560SEL was sold new by West Orange Motors, in Orange NSW. The original owner lived in Western Sydney, but had business in Orange and Dubbo. While it was sold new in Orange, it was serviced at Marshalls in Parramatta until 230,000km. Presumably, the car made a fair few trips up to Orange, Dubbo and the surrounding area over its life. The original stamp from West Orange motors is still in the service book. I can’t imagine that many 560SELs were sold outside the main dealers in Sydney, Sydney Eastern Suburbs, Melbourne City and suburbs like Toorak. The original owner […]

Sydney scenic drives

Most of the articles on Sydney Scenic drives list the same old drives everyone knows. I’ve had a free day once a week for the last couple of months. Its given me the opportunity to explore different roads a day trip away from Sydney. I don’t normally get the chance to go long drives, to it was also a good opportunity to give all the cars a good run. The idea was to leave about 7:30AM, and return by 6PM, leaving time for a few breaks.

The idea was to find some good roads for the classic car driver who […]

December 2020 W126 Price Guide – Australia

When I wrote my W126 buyers guide earlier in the year, I did not include price information. Pricing is very specific to each location and changes frequently. This W126 price guide covers my observations about the prices of W126s in Australia. Its likely to be valid for the next year or so.

There are a few factors that impact the price of a W126. Some models, years and options are worth more than others. This is particularly the case for the W126 which had different body styles, engines and even two distinct series. As an example, the V8 models are […]

M117 Auxiliary fan cut-in modification

Under normal operation, the auxiliary fan on the M117 engine cuts in at 105C. It can also be triggered by A/C system pressure. These settings work fine to keep the engine at the correct temperature. The challenge is that most of these cars have been converted to R134A refrigerant. R134A is far less efficient than R12. The A/C system in the W126 was designed for R12 so is now under specified. Add in the hot Australian climate and stop/go Sydney traffic and you end up with a hot engine and poor A/C performance.

I’ve noticed that once the coolant temperature […]

W126 auxiliary fan replacement

Now we have hit summer here in Sydney, it was apparent that the auxiliary fan was not working. The fan is triggered either by high coolant temperature, or refrigerant pressure. High coolant temperature causes the fan to run at full speed. Refrigerant temperature can trigger a slower fan speed based on a resistor. Before I just jumped into W126 auxiliary fan replacement, I tested the existing fan.

The first test is to jump the wires at the coolant temperature probe. This should trigger high speed running. The next is the sensor on the A/C receiver/drier which should trigger low speed […]