Your story, what happens when your secondary filter is plugged. - PeachParts Mercedes-Benz Forum

whunter · #1 12-27-2005, 06:02 PM

Your story, what happens when your secondary filter is plugged.

If you have a thread, please paste the link here.

P.E.Haiges · #2 12-27-2005, 07:37 PM

whunter,

When one of my fuel filter starts to plug up, the engine power is reduced. This is most noticeable on an upgrade. When the tractor trailers start passing me and I have the accelerator to the floor, I know one of the fuel filters needs to be replaced.

First I check the primary filter by taking it off and blowing into the intake. If the fuel doesn't squirt out the outlet, the filter is plugged and is replaced. If I blow thru it and the fuel squirts out easily, I reinstall the primary filter and R&R the secondary fuel filter.

That has always fixed the problem for me except the one time the fuel tank strainer was plugged by fungus. I have never seen a situation where both primary and secondary filters were plugged at the same time.

P E H

boneheaddoctor · #3 12-27-2005, 07:49 PM

I've plugged or at least came close to plugging a couple primary filters....but never a secondary...I change those once a year on principle...and the primary when I see a large accumulation of crud.

Palangi · #4 12-27-2005, 08:01 PM

When my 240D was having water/fungus/rust problems, it was generally OK on the highway. After pulling off the hwy and going to idle, for example at a stop sign, it would fall flat shortly after take off. For example it might get up to 10 mph and would not accellerate beyond that speed. Usually just letting the krud out of the prefilter would fix it. I was surprised to find that the prefilter does, in fact, separate some water. Not sure how that happens physics-wise, but it does.

Hatterasguy · #5 12-27-2005, 08:05 PM

Ah yes the SD has given me good practice in this!

When the car has no power and isn't running well I will inspect the clear filter. If the screen is black I'll change that and see if it fixes anything. If power is still down I'll put spin on a new canister.

Once the fungus is dead I'll revert to the usual once a year schedual.

mac2 · #6 12-27-2005, 08:23 PM

Using WVO I know all about plugged filters. When one of the inlines gets clogged it starts revving up and down at high speed (above 60 mph) and reduced power and shaky takeoffs from a stop.

And if I really messed up and got bad oil in the tank It'll get up to speed and then spontaneously die.

Always carry extra filters......

P.E.Haiges · #7 12-27-2005, 11:33 PM

Geeze, what a waste of money, changing filters every year.

When mine plug up, I clean them out and use them again.

P E H

sailor15015 · #8 12-28-2005, 12:05 AM

I run my WVO in a separated, heated system and I've never had an infestation in my tank so I just replace them both every other oil change on principal. They're not that expensive.

pawoSD · #9 12-28-2005, 12:10 AM

I haven't changed my spin on filter in nearly two years, and it seems to be running great still....I may replace it this summer just to see how much stuff is accumulated in it (and I will be doing some very very long trips, so why not). I changed my primary about 4 months ago because it looked dark, turned out it was just coated on the outside in gook, not much of anything on the inside on further inspection!! Current one is still clear with only a few flecks caught on the screen.....filters last me forever. We've never replaced the spin on one on the 83, only the primary about a year ago because it had some gunk in it. Its been idling rougher (when it last ran) and slower on acceleration, so I'll probably change the spin on once its back on the road again....we have two laying around so why not.

#10 12-28-2005, 02:16 AM

If I can't light up a tire when dropping into second gear when driving around...

...I know something is wrong.

Going to change the filter this weekend. Ordered one and it is on its way..along with a bunch of other parts. Most noticeable my low speed takeoff is very poor...the slight restriction from the fuel filter really kicks in there. I can still do triple digits but the bottom end suffers the most...most likely due to the slow and realitivly low power pulses coming from the lift pump. That little restriction makes all the difference.

But then again I can notice the difference between 3/4 tank and 1/4 tank and its effect on my engines performance (not just the weight difference...my car is actually currently faster with 3/4 tank since the filter is not super clean)

pawoSD · #11 12-28-2005, 02:25 AM

I have actually felt that my car does feel more sluggish lately, and its also been taking a couple extra cranks to get it going (cold) at any temp below 35 or so....I suspect my spin on filter, its old....since we have some I might just replace it tomorrow and see what it does....might as well (plus I will dremel it open and take some pix for you all!!

)....my bottom end acceleration has also become a lot worse recently, not nearly the relentless roar that it used to be. I too can notice the increase in acceleration with the car empty and low on fuel...then I fill it up and have a couple people riding with me and it really hurts acceleration....I want stop and say...get out!

Glow plugs are all working, so the delay on startup is probably fuel related....we'll see. I have a brand new Hengst and Bosch filter in a box in the garage somewhere......

Diesel Giant · #12 12-28-2005, 11:11 AM

Clogged filter = no fuel flow= no foward movement.

Padraig · #13 12-28-2005, 12:59 PM

Quote:

Originally Posted by Palangi

When my 240D was having water/fungus/rust problems, it was generally OK on the highway. After pulling off the hwy and going to idle, for example at a stop sign, it would fall flat shortly after take off. For example it might get up to 10 mph and would not accellerate beyond that speed. Usually just letting the krud out of the prefilter would fix it. I was surprised to find that the prefilter does, in fact, separate some water. Not sure how that happens physics-wise, but it does.

Palangi, you are the one exception to properly name the fuel filter that serves the I.P., as the "Pre-Filter". I have always been confused with others referring to it as the Primary filter. "Primary", afterall, means first and therefore it is the first filter from the fuel tank. That would make the 'Pre-filter' the seconadary one - wouldn't it?

Palangi · #14 12-28-2005, 01:08 PM

Yea, I know. The naming of the filters can be confusing. As far as I am concerned, the plastic filter is the prefilter, and the spin-on filter is the main filter, but that naming convention may get you slapped down around here, so, simply to avoid confusion, I just say prefilter and spin-on filter.

Rich300TDMBZ · #15 12-28-2005, 05:15 PM

I got a couple of prefilters from the dealer and they are different from the ones I normally get.
The ones from the dealer have the Mercedes symbol and the #0014776601 on them (made in Germany).
They are made of white plastic, a bit longer, and are NOT clear or transparent.
How can you tell using these Mercedes prefilters that they are dirty or blocked?
Do you just changed them at a predetermined interval?
Have any of you used them before?[/