I was looking at my 84 300D engine and realized that the air cleaner really puts a lot of twists and turns in the flow path for the air coming in. I was thinking about streamlining this flow with an aftermarket air cleaner/intake piping. Has anyone else done this, or can recommend this for increased fuel mileage and/or power from their engine?
Additionally, the engine has 263k miles on it, does that make a difference?
MB filter housing is the best... I would not change it for anything. Alot of time, these aftermarket filters makes things worse... especially for gas engine.... like those conical one that requires you to eliminate your factory airbox... those are just dumb as it is sucking hot engine air rather than colder denser air via air duct.
The turbo boosts the intake pressure to as much as 11 psi at full throttle. That's about the limit for the engine, especially after 26K miles. Forget it.
Thats my point though. The factory airbox has a lot of restrictions and turns to get to the turbo intake. Additionally, the "cold" air intake for the factory air duct is only about a 1"x6" slot mounted above the passenger headlight with a 2" plastic hose leading to the filter housing. Not nearly as large as an aftermarket pipe would be pulling in air directly from below the car (i.e. away from the engine). Whether it is 50F hotter air or not doesn't make a difference if there is 4x the volume getting to the turbo (or 4x less depending on your POV). Another concern is to get the housing off of the top of the turbo and exhaust. That is the hottest part of the engine, and it basically turns the housing into an oven. My thought was to provide a K&N filter housing that would draw air from a cooler part of the car (not the hood) lower in the engine compartment, with a much larger pipe to get the most air into the turbo, while also moving the filter from atop the turbo and exhaust manifold. I should mention that since this car is my daily driver at the moment, I won't actually be performing any of this work yet. I just want to do a little research and thought that I would bounce some ideas off of this newsgroup.
Secondly, has anyone noticed any adverse effects when removing the PCV tube that goes to the air filter? I don't mind recycling those blow-by gases, but it sure does get the air filter nasty.
On Aug 2, 7:58 pm, "-->> T.G. Lambach
With turbo, it doesn't matter... because the turbo takes care of the restrictions like any compressor would. It is trivial... or othertwise MB wouldn't design it that way.
Drawing cool air from bottom of engine compartment will lead to suction of water in rainy day from splashes and will destroy the turbo and engine. You can't compress water
On 95 E300D, MB actually made snorkel fins on the passenger side fender for cold air intake. On your car, I think it is from behind headlight area.
Turbo will heat up the air... and it doesn't matter if you could get 4x more air... turbo will only pushes as much as it can... 11 PSI... and drawing hot air at that pressure will lead to even hotter air and less O2 than the factory air duct routing.
There is much easier way to get 5 extra MPG... just put in Marvel Mystery Oil into your fuel... 4 to 6 oz per 10 gallons of fuel. It is cheap enough and no messing with air filter.
Routine Diesel Purge will make sure you injectors are clean... this is much more important than anything else.
The turbo boost specification is 10.2 - 11.6 psi at 4,000 engine rpm, under load in L or S gear.
The safety switch on the intake manifold opens at 16 psi to prevent a runaway engine.
These engines were "efficient" in their time - about 40 HP / L. That's what gas engine were making at that time too.
The way to have an efficient engine is to regularly change its oil and filter, keep its valves adjusted, replace the injectors with Bosch remanufactured ones (to improve the spray pattern) and keep the paper air filter clean. Then leave it alone to do its job.
I've driven a '80 300SD since new and do those things and it runs like it did when it was new.
On Aug 3, 9:38 pm, "-->> T.G. Lambach
Most popular is the Chevron Delo... followed by the Mobil Delvac followed by Shell Rotella. All three are excellent oil and all can be bought at Walmart... (I am not sure about Delvac)
15W40 is the standard oil for diesel engine.5W40 is the standard for diesel synthetic oil.... Shell Rotella Synthetic oil is the best deal at $4 a quart when bought in gallon size. Better oils are Mobil 1 and Amsoil... but they are much pricier... 50% more.
For my 1980 300SD, the manual lists 15-40 as acceptable for temps above 23F. Below that, it's 10-40. So, I use the Rotella in most months, and a diesel rated 10-40, think it is Valvoline in winter.
Chevron Delo 400 15 - 40 CI - 4Plus and an OEM filter (Mahle-Knecht) that I buy from
If you have no leak or excessive oil lost, then it should be fine. I switched to synthetic when engine are at like 205,000 miles or 196,000 miles... two different cars. Another one at like 115,000 miles. no problem with any of them.
That's what I used.... the Shell Rotell Synthetic. It is great in winter.
What kind of oil change interval do you follow with the synthetic?
JD
For the diesel, it would be extra nice to just change the oil filter at 5000 miles and change both at 10,000 miles.
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