W123 鈥?Fuel Pressure Relief Valve

W123 鈥?Fuel Pressure Relief Valve

The Fuel Pressure Relief Valve. It's simple, quick and just might make all the difference in the world. It's hard to believe just how much bad information gets on the web. What's worse is how gullible we often are to buy into it without question or further research. On occasion I scour the web to see what bad information I can find on ways people suggest fixing particular automotive problems. After just a few minutes of reading or watching a Youtube video, it becomes evident most people never read the workshop manual. For 99% of any problem that will arise on your car, there is a corresponding fix from the manufacturer. No guessing required what so ever. Unfortunately so many great older cars are being butchered from bad advice, laziness, or the assumption the manufacturer had no clue what they were doing from the start. Indeed there are manufacturers who built very unreliable products that should have never been put on a car, but as it pertains to Mercedes, there are few components that were engineered that did not perform near flawlessly.

With that in mind, if your diesel is still running rough with all the previously mentioned items checked or replaced, there is one last component to getting your W123 diesel to run like it did from day one. The Fuel Pressure Relief Valve. Locate Fuel Pressure Relief Valve highlighted in green. Remove valve. Fuel will run out so have a rag under the valve and/or a drip pan under the car. Note from photo wish bolt to loosen. Once the valve has been removed, it will need to be separated and checked. To separate, either hold with two wrenches or carefully place in a vice and loosen the top "bolt" cap. Separate valve by hand and over a pan or rag. A spring and ball bearing are inside. Once separated, the is what you will see. Make sure everything is thoroughly cleaned after taking this apart. It should already be very clean since fuel is constantly flowing through this valve. It can however attract sludge depending on how the car has been maintained. Once clean, measure the spring using a micrometer. When I measured the spring that was removed from my valve, it measured 19.76mm. According to the Mercedes-Benz worship manual it can measure up to 27mm max. Based on the max of 27mm, I gently stretched the spring to 25mm exactly, and reinstalled. This simple procedure made the most drastic difference of anything I could have done.

Why bother with a two-door car? They鈥檙e far less practical than their four-door counterparts, rear-seat access generally requires the flexibility of a gymnast, and their long doors are a pain in tight parking lots. It used to be that a two-door was cheaper than the equivalent four-door, but now they often cost more. They may be fractionally lighter, but that鈥檚 not guaranteed. The only real reason to choose a coupe is for looks. In previous generations of the Mercedes-Benz C-class, however, the model labeled a coupe was more of a staid two-door sedan. The new one makes a more dramatic break from the four-door model: Its roofline is 1.5 inches lower and tapers quickly to the rounded tail. The taillamps are horizontal rather than vertical, just as they are on the S-class coupe, and the license plate moves down to the bumper, leaving a cleaner trunklid. On the sedan, the body-side crease dips as it travels front to rear, while it remains straight on the coupe, and the whole car sits lower on its wheels.

Turning up the style wattage out front is a larger, lower grille that鈥檚 a constellation of floating chrome stars, another design element borrowed from the range-topping two-door. The visual drama continues inside. The dash is the same as that of the C-class sedan鈥攊n fact, much of the interior design is shared. And, really, why shouldn鈥檛 it be? 60,000. Here, too, exquisite materials and liberally applied brightwork make this cabin a visual and tactile delight. 4500 Premium 2 Package). At least an oversize sunroof is standard鈥攁s it is (coincidentally?) in the BMW 4-series鈥攖he better to illuminate the cozy cabin. And it is cozy. The inviting front thrones with integral headrests are as comfortable as they look, but the seating position is lower than in the sedan. Behind are two rear seats, but it鈥檚 a feat getting back there, and their unfortunate occupants quickly come to understand the sacrifices made for that sloping, tapered roofline.