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...
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...
Today’s job was EHA replacement (Electro-Hydraulic Actuator) on my 1987 560SEL. The EHA is part of the KE Jetronic fuel injection system and makes minute adjustments to the air/fuel mixture. One of the sources for these adjustment is the oxygen sensor, if present. The EHA can leak either because the o-rings between the EHA and the fuel distributor have gone hard, or because of...
The monthly late night drives are really starting to gain momentum. This month was a bit different. It started out as a Night drive to Bilpin. As well as a drive, we had late night dessert and coffee. Summer in Sydney is a great time for night drives. The weather is pleasant and its a great time for convertibles or sunroofs to be open....
The W126 battery tray serves a dual purpose. The first and most obvious is to keep the battery in place. The other is to protect the body work. Over time car batteries can leak acid and the removable tray catches all that. It is worth checking the condition of the battery tray each time the battery is replaced. If the battery tray becomes...
Today I took my 300SE on a Mercedes Club Pop up drive. The Pop up drives are short notice mid-week drives. I normally take the other cars to club events, but the 300SE had not been on a decent run for a while and the weather was terrible. The drive was down through the Royal National park to Mt Kembla, Mt Kiera and then...
The Mercedes Benz club NSW ran an event today to commemorate the cars of Bruno Sacco. Sacco was head of design at Mercedes-Benz from 1975-1999. The event was called Youngtimer Sacco day and I understand the intention is to make it an annual event. Given the success of today’s event, I can easily see why. The event started out at Tynan’s Mercedes-Benz dealership...
After all the recent work done on my 250SE, I wanted to take it for an extended test drive. Its had motor and transmission mounts, front crank seal, re-sealed power steering pump, injectors, distributor cap and rotor, points, condenser, coil, plugs, alternator, voltage regulator and more done. The spark had been quite weak and the engine was carboned up. The Mercedes-Benz club have...
On the way back from the September night drive my 250SE stopped charging properly. I was able to make it back home about an hour on the battery. Even using the headlights the 250SE does not use a lot of power. As it happened, a friend of mine had a rebuilt alternator that was correct for my car. He drives a 280SE 3.5 W108...
Over the last couple of months I’ve had issues with the M129 rough running in my 250SE. The car was hesitating, idling poorly and just not running very well. I’ve done a few things over the last few months to improve this situation. One of the first things I did was change the injectors. The stutter when accelerating and hard starting when hot felt...
I recently changed the fuel pump and rear fuel hoses on my Jaguar E-Type. In doing this change I learned a few things. Firstly, the old pump had not been delivering enough fuel, as the car was significantly more responsive. Secondly, fuel had obviously been leaking for a while as the paint had been eaten away in the spare tyre well. For both these...
Today I went on a drive with the MBCNSW to visit some historic dams to the South of Sydney. The idea was to supposed to be to go to each dam and check it out and then have a picnic lunch at one of them. Unfortunately the Sydney weather did not play ball and it was a rather wet and wild day. I brought...
Over the last couple of months I have been doing a monthly night drive with a few friends in the Mercedes Club. This month was the first time it was an official event. When they were unofficial we did drives such as the Old Pacific Highway, the Old Northern Road and down to Bulli. This time we did a night drive to Palm Beach. ...
An obvious issue on my 560SEL was how the rear seat was mounted. There was an obvious gap between the parcel shelf and the rear seat. The 560SEL came standard with a W126 power rear seat. This either standard or optional on other W126 LWB models. It seemed clear that when the self-leveling rear suspension was removed, the trim was not put back correctly....
The other day I was driving my 560SEL on a fairly hot (30C) day in heavy traffic. The engine temperature got quite warm when sitting in traffic. It was well over 100C in traffic, which would eventually cool down when I got moving. The car didn’t overheat, but I did hear coolant boiling in the radiator hose after I finished the drive. While the...
I have now completed the installation of the Movovalve elimination kit on my 560SEC. So far so good. Most importantly, I don’t have heat when I don’t want it, but it is available when needed. In the last installment, I completed the routing of the cooling hoses. From there I installed the radiator and ensured the cooling system didn’t have any leaks. The...
More Posts
