PeachParts Mercedes-Benz Forum - View Single Post

jay_bob · #10 10-08-2014, 07:53 AM

I have done this job it is not too bad.

First disconnect the battery, the + terminal on the starter is close to the sensor and you don't want to cause a short.

When I looked at it, I first thought about going up from the bottom but the starter is in the way.

I ended up going at it from above. You'll need to remove the intake manifold. So pick up a new intake manifold and cross over pipe gasket as well.

I would also check the condition of the injection line clips while you are removing the manifold. If any are loose or missing I would replace them all. The plastic gets brittle with age. If you don't secure the injection lines properly they will vibrate and then leak.

And of course you will find the manifold is plugged up with EGR deposits. That's another squirrel to chase.

Drain about a gallon of the coolant into a clean container (use the red drain plug under the radiator).

Disconnect the fuel preheater at the left rear corner of the block and move it out of the way. No need to disconnect the fuel lines but you will need to remove the heater hose connection. Get a new o-ring for this as well. It just pulls out of the block after you have removed the clip holding it on. Stuff a clean rubber glove into the port in the block to keep coolant from dripping and keep contaminants out of the hole.

Now you have clear access to the oil pressure sensor. It is a little silver can at the base of the oil filter. When you remove it you will lose maybe a teaspoon of oil so no need to drain the engine oil first. The electrical wire just pulls straight off the pin connection and the sensor unscrews from the oil filter base.

When you go to put the coolant back in, use a funnel with a coffee filter in it. Remove the upper radiator hose from the radiator and pour as much of the coolant as you can directly into the block, much faster than trying to put it back in through the tank. This also helps the trapped air pocket escape from the head.