Importance of Fuel Filters - PeachParts Mercedes-Benz Forum

FE240D · #1 10-27-2015, 10:44 PM

Familiar with gassers but not diesels, just purchased an '82 auto 240d and drove it home 3 hrs through very hilly terrain in SW Wisc. and into NE Iowa. Rust-free and excellent condition, 140k mileage were pluses, literally an older ladies car who left it to a friend a year+ 1/2 ago. Nonetheless, I began to have some serious buyers remorse that sank in as I hit the "hills" around DuBuque and up and along the Mississippi.. I knew the car was underpowered but as everyone zipped by, I lost serious speed 25% into a hill and slowed to 20mph near the top of the hill. The car was winding high revs but alas no power. It also felt like the trans was slipping. Everyone else zipped by me as I struggled up in the right lane.
Today, I quickly got my hands on a new filter set, installed them and now love the car! i went back to the last 'killer' hill near home that I struggled up at 20mph yesterday (with a parade of cars behind) and it took the hill at 50-55 mph today. What a difference and thank God for these forums with such abundant info! Question is, what do you think I should change next- trans flush/filter, oil change, air filter, valve adjust, anything I missed? Thx

vstech · #2 10-28-2015, 08:45 AM

if you have zero maintenance history, the best bet is to change all the fluids, and install fresh filters.

do you still have the clear fuel filter? look in it for crunchies... if it's full of clear slime, your tank may have bad fuel in it. diesel gathers critters that will break down the fuel and form asphalt that will clog your tank filters. that's a priority.

next, I'd pull the oil, transmission fluid *(and that includes draining the torque converter), brake fluid, and power steering fluid (this also has a filter in the reservoir). get all those changed, and you will be more cofident with your car.
air filter, and valve adjust is also important for a smooth running car.
the fuel pressure is known to cause problems with the 240, that results in a bad $1 cylinder, so get that checked as well.
lastly getting the accelerator linkage well adjusted is wise.

leathermang · #3 10-28-2015, 09:38 AM

Adjust the valves FIRST.....
this is not a hard choice because if the valves get too tight then you can BURN a valve... this is a huge expense to fix...

Diesel911 · #4 10-28-2015, 10:24 AM

Quote:

Originally Posted by FE240D

Familiar with gassers but not diesels, just purchased an '82 auto 240d and drove it home 3 hrs through very hilly terrain in SW Wisc. and into NE Iowa. Rust-free and excellent condition, 140k mileage were pluses, literally an older ladies car who left it to a friend a year+ 1/2 ago. Nonetheless, I began to have some serious buyers remorse that sank in as I hit the "hills" around DuBuque and up and along the Mississippi.. I knew the car was underpowered but as everyone zipped by, I lost serious speed 25% into a hill and slowed to 20mph near the top of the hill. The car was winding high revs but alas no power. It also felt like the trans was slipping. Everyone else zipped by me as I struggled up in the right lane.
Today, I quickly got my hands on a new filter set, installed them and now love the car! i went back to the last 'killer' hill near home that I struggled up at 20mph yesterday (with a parade of cars behind) and it took the hill at 50-55 mph today. What a difference and thank God for these forums with such abundant info! Question is, what do you think I should change next- trans flush/filter, oil change, air filter, valve adjust, anything I missed? Thx

Did you see anything inside of the Plastic/Primary Fuel Fuel Filter?

Diesel Fuel has more stuff in it then Gasoline does that needs to be filter out even when it is clean.

You can get contaminated diesel fuel right from the Pump that can actually stop yo somewhere on ther Road (keep a set of filters and O-rings in the trunk).

Then there is that fact that stuff can grow in the Fuel Tank and that stuff can easily plug up Filters.

If you bought the Car and that Car sat a long time not being used there is an increased chance that something is growing inside of the Fuel Tank.

vince77 · #5 10-28-2015, 10:46 AM

Congrats on your find. I'm a few months into rescuing a 240D as well... biggest change, hands down was the valve adjustment. I made a list and have been ticking off a few items every other weekend or so. The big ones for me were oil and coolant because I just didn't like the look of either...

vstech is right though, all the filters eventually, and belts as well since they're cheap too. Heck of a list over here.

I've seen a couple transmissions die over the years immediately after a fluid flush, so I'm going to start with a partial trans fluid change (leave the torque converter filled) along with a new filter/gasket. Feels safer that way rather than shocking it with a full dose of fresh cleaning/lubricating agents. Probably overly cautious, but I'll sleep better.

Mine was shifting terribly when I got it, but it's so dependent on vacuum and throttle linkages, you can't assume the problem in the trans. Every tweak has improved it, even the valve adjustment oddly enough.

leathermang · #6 10-28-2015, 10:51 AM

Quote:

Originally Posted by vince77

......I've seen a couple transmissions die over the years immediately after a fluid flush, so I'm going to start with a partial trans fluid change (leave the torque converter filled) along with a new filter/gasket. Feels safer that way rather than shocking it with a full dose of fresh cleaning/lubricating agents. Probably overly cautious, but I'll sleep better.

Totally Faulty ' Logic '..... this has been discussed in threads before.. they are in the archives....
' Shocking ' is something that happens to animals... like Wind Chill... not machines...
Change all the fluid and filters.. just like the FSM says to do....

vince77 · #7 10-28-2015, 11:09 AM

Makes sense. And the transmissions that died we're likely already a breath away from deaths door anyway, but again, I'll sleep better at least thinking I played it safe.

By the way, what page of the FSM talks about transmission service for potentially 30 year old fluid?

vstech · #8 10-28-2015, 11:17 AM

Quote:

Originally Posted by leathermang

Totally Faulty ' Logic '..... this has been discussed in threads before.. they are in the archives....
' Shocking ' is something that happens to animals... like Wind Chill... not machines...
Change all the fluid and filters.. just like the FSM says to do....

no, I disagree here...
while the wording "shocking" may not be right for the transmission, I understand that heavily shrunken seals is exposed to massive softeners all at once can lead to them overly expanding, and falling out.

a good practice on a leaking system would be to drain out portions of the fluid and slowly introducing the chemicals.

I'd drain like 2 quarts, and replace with 2, then 4 quarts and replace with 4 and so on, until the entire quantity of fluid was changed.

FE240D · #9 10-28-2015, 11:25 AM

Quote:

Originally Posted by Diesel911

Did you see anything inside of the Plastic/Primary Fuel Fuel Filter?

Diesel Fuel has more stuff in it then Gasoline does that needs to be filter out even when it is clean.

You can get contaminated diesel fuel right from the Pump that can actually stop yo somewhere on ther Road (keep a set of filters and O-rings in the trunk).

Then there is that fact that stuff can grow in the Fuel Tank and that stuff can easily plug up Filters.

If you bought the Car and that Car sat a long time not being used there is an increased chance that something is growing inside of the Fuel Tank.

Thanks for all the pointers and priority, I have the valve adjust set up for next week along with an oil change and today I got the plastic pre filter so will replace/examine that old one for crud. My hunch is that it was maintained but in the last year not so much and because it was not hardly driven so lining up what needs to be done to get a baseline.

Just a new filter made the tranny run smoother and after pushing the carpet away from the kickdown switch I no longer have to manually downshift. What a harrowing 3 hr trip that was home...

What a surprisingly well built car though and not a pain to work on. Being an endless tinkerer and perfectionist always ready to get the hands dirty, I think I will be a good owner for "Gretel" as I now call her.. Since it is rust free I was going to have the wax sprayed in the panels but the manual alluded to the fact they surprisingly did this at the factory? Dont see that any more..

leathermang · #10 10-28-2015, 11:56 AM

Quote:

Originally Posted by vstech

if you have zero maintenance history, the best bet is to change all the fluids, and install fresh filters......
next, I'd pull the oil, transmission fluid *(and that includes draining the torque converter), brake fluid, and power steering fluid (this also has a filter in the reservoir). get all those changed, and you will be more cofident with your car..
.

You had it right the first time...
there is no evidence of ' massively shrunken seals' or' massive softeners' .. only good new trans fluid replacing really old trans fluid....

Mxfrank · #11 10-28-2015, 11:57 AM

I've heard enough tales of transmissions failing after a fluid change to believe there's something there. I don't agree with any of the armchair analysis, and I don't know of any serious post-mortem, but it certainly seems to happen.

My 190D doesn't have a torque converter drain plug for some reason. So what I do is suction the transmission pan out every time I change engine oil...about two quarts comes out. That's what I put back in. Change the filters once every great while. The original transmission made it to 320K miles with this routine, I don't see a lot of them lasting longer than that.

leathermang · #12 10-28-2015, 12:02 PM

Quote:

Originally Posted by Mxfrank

I've heard enough tales of transmissions failing after a fluid change to believe there's something there. I don't agree with any of the armchair analysis, and I don't know of any serious post-mortem, but it certainly seems to happen....

It is common for human beings to equate things which have a Temporal relationship.... happens ' close ' in time....
to a Causal Relationship.....
that is why double blind studies and control groups are used when testing all sorts of things.

Mxfrank · #13 10-28-2015, 12:24 PM

Agreed. Just as there's never been a double blind study to prove that jamba juice can fix a transmission by dissolving "varnish".

BayouFlyFisher · #14 10-28-2015, 12:25 PM

My Dad used to say, just because lunch comes after breakfast does not mean that lunch is caused by breakfast.

babymog · #15 10-28-2015, 12:25 PM

Transmission fluid changes don't kill transmissions, but a flush can.

Do it the right way, drain and drop the pan, drain the TC, change the filter and fluid (and if it isn't shifting well this is a good time to change whatever cheap and easy valve-body or piston parts are sooo accessible at that point).

A flush can overfill/underfill while the car is running and is a transmission rebuilder's best friend as they are known by these same people to be great business-builders.