M.L.X.

according to the discussion on that link Bosch parted ways with Champion...
and Bosch/Mann purchased Purolator?

they seem to like the oil filter...

humm... not sure if I want to use it or not if it's not good like Glyn said...

sknight

Case by case, like I said. In the case of Audi/VW, even the high end aftermarkets had bypass valves which were set too low, for instance. In some cases, piece of mind might outweigh the costs. In my case, I have the luxury of being able to buy the exact part aftermarket, right from any shop, but for a savings. They might like it on that forum, but that is not real data. I love the filters that have cases that balloon under pressure. That's always good for a laugh. The bypass resulting in unfiltered oil flowing for longer is an issue, I would think, but I'm looking for filtering. In my case, like last Sunday, I was running at 4000+ rpm for well over an hour on a trip home. Don't want blowouts of the media and definitely want to ensure the fuel filter is working right.

M.L.X.

oem MAHLE-KNECHT fuel filter isn't that much.

$41.66 from rmeuropean.

funny thing is the oem filter is cheaper then the Bosch from rmeuropean.

ended up with the Bosch one because I wanted to get some power steering fluid and in order to qualify for the free shipping from AutohaustAZ, order needed to be of certain amount.
at the time didn't need anything else but I knew fuel filter change was coming up so ended up picking up the Bosch since they don't carry the Mahle-Knecht.

maybe it wasn't a smart move...

C230 Sport Coup

Aye, keep yer panties on...my eyes aint that bad,
I can still read, with glasses.
No need to get testes.

Going forward I'll definitely use the Kneckt.
Wasn't aware of all these quality issues at Bosch.
Well, of course there is the old joke, why do the germans drink warm beer;
Bosch refrigerators.
Now I'm wondering if I shouldn't pull the bosch.

I used a Bosch oil filter last time around, an add-on to get the free shipping.
Wow, rockauto has Mann oil filters for the M111 for $4.24

ba114

woke up this morning to find my 2001 C180 would no longer turn over. Cranks continuously but never starts.

Pressed the fuel rail pressure valve and nothing came out. Will be testing with a pressure tester tonight, and most likely have to get a replacement filter (hasnt been done in a LONG time).

Hopefully thats all it is.... FYI - i got quoted $99 for a replacement here in Australia

Glyn M Ruck

Filter, or maybe pump - hold thumbs! Sort out fuel supply first - Then look at CPS if no success.

rabney72

I have a similar problem. I replaced my fuel filter about 3 months ago with a MANN Part #WK720. The car has been running fine ever since until last monday when I last filled up the tank. About 20-30 miles after fill up the car started acting like it had no power would buck on gear shifts. Then it would barely start the next few start ups (after cranking 5 times it would blip on barely, then I'd give it gas and it would finally start). Now it wont start at all, it turns over and over, but no fire.... and NO CEL which is a shocker.

So I guess I'll check the fuel pressure and spark, but if that's good then what?

- bad gas? I can pull the fuel line off the filter and prime it out
- Clean the maf? Ive searched and read mixed opinions on this?
- clean throttle body? I mean come on, this couldn't keep it from starting could it?
- Compressor is seized (is there a clutch on this thing) ? It sure didn't feel like it was making power during the short period where the car ran but like crap. What about a boost pressure relief valve being stuck open?
- Vacuum leak?
- some kind of crank position sensor or camshaft position sensor? (besides fuel and spark, this is about the only think to keep this thing from running)

BTW car has recent (within past 6 months) motor and tranny oil and filter change, and yes I used the 15$ a quart tranny fluid.

Thanks all

Rob

efzauner

My Hayes manual suggests removing the fuel filter fuse and turning over the engine to relieve the pressure. I have a 2005 C240 v6 of course. Comments?

Glyn M Ruck

You can do that or just relieve pressure at the valve on the fuel injector rail.

rabney72

So I just put the fuel pressure guage on the car, no pressure with car off. Turn key to ignition, fuel pump primes but no pressure. Turn key to start (full on) car turns over but won't fire, but fuel pressure slowly builds. Car only cycles a few times and the fuel pressure immediately drops once it stops turning over. So I immediatey cycle ignition and then fuel pressure builds enough so car will start (continuing from where it fell builds enough pressure. It holds 40psi at idle, but drops rapidly as I rev the engine.

What is the culprit?

Seems like pump is weak and the check valve is not working properly?? Maybe the filter is causing both these problems??

Thanks guys

rabney72

Anybody ever done a fuel pump job?

rabney72

Anybody have an experience with Mann fuel filters? Good or bad? I guess since there is a regulator in the filter it's more important than your usual filter. What about a check valve?

Glyn M Ruck

Fuel pressure should come up to spec immediately. You might have a clogged filter or the pressure regulator might be damaged inside the filter. It sounds like fuel pump to me.

Install university has a complete pump replacement method. It's easy.

Here

rabney72

I agree Glyn, gonna do a quick filter change and if that doesn't work, go fuel pump route.

Glyn M Ruck

See R&R - I edited my post.

rabney72

I just checked again, it has absolutely zero pressure now, gotta be the pump.

Glyn M Ruck

Sounds like it. Injectors need full pressure to atomise properly.

rabney72

Glyn nailed it on one of his old posts about the regulator being in the filter. The regulator was stuck open and it was just dumping fuel back in the tank (basically just making a loop so no pressure would build. A very poor mechanical design methodology on Mercedes part to put the regulator in the filter IMO. For one it means an unnecessary regulator swap everytime you do a fuel filter, two it drives up the cost of the filter, and three the design sucks and is unreliable (probably somewhat due to the higher ethanol content in fuel these days). Its the first time in my life that a fuel pressure regulator went bad on me. Anyway , car runs like a champ now ... So much for preventative maintenance , if i would of left the factory filter on there at 70k this probably wouldn't of happened...

Thanks
Rob

Glyn M Ruck

Damn, another filter giving trouble. Last one was d1no. OK in future default recommendation will be do filter even if new before pump.

Great!

hanknum

Hey Guys,

I replaced my filter on my C320 a few months ago and all was fine. A few weeks ago my wife said there was a loud humming noise. It sounds like it is coming from the fuel pump. I replaced the filter with an OEM from the dealer. Do you think I got a defective filter? Any thioughts?

W203E35

It might be a fuel filter again. Try to replace the fuel filter first and see if it goes away. If so then great if not then it maybe the fuel pump.

hanknum

Hey Karo,

Today I actually stopped by the dealer and bumped into a tech in the parking lot. I asked him about the humming noise...he asked if it was coming from the pump or the filter. Has anyone heard of this noise coming from the filter? I have not gone under the car, but assumed that it was from the pump. The tech said that he has seen some defective filters. Of course, it was not making the noise when I was there.

W203E35

The pump does make the sound and the filter does too. Sometimes when it's a bad filter or an old filter and something is clogged it'll make the humming sound. A clogged filter will put more stress on the pump.

If you change the filter again will you be able to tell if that was the remedy right away? Or is the sound intermittent?

Sorry to go into too much detail but to answer your question yes filters would make the humming noise if it's defective or if something is clogged.

Since the filter is a cheap fix change that first and go from there. The pump is a real PITA (from what I hear).

Can you return your defective filter?

rabney72

IMO, the pump is more likely to humm than the filter. It could be both but likely the pump is humming from a clogged filter.

Well lets backtrack a little bit, how is the car running? If it runs great with no loss in power at high rpm, its likely not the filter but a pump going bad. Or something else.

I doubt your filter is already clogged...but then again, I didn't think anybody was stupid enough to put a regulator inside a fuel filter.

Glyn M Ruck

The filter can't make a noise. Only the pump. Filter might not be clogged but the pressure regulator could be faulty. I think likely pump trouble. Change filter first.