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2000 ML430 SOLD, 2007 BMW 328i Coupe, 2014 BMW i3
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2,982 Posts
Discussion Starter #1
Are the fuel injector pumps on diesels known for poor reliability? I am writing on behalf a 1998 E300 turbodiesel owner who just had their second replacement fuel injector pump replaced within a year or so.

The car has 80,000 miles and was originally displaying symptoms of rough idle and power loss when the first pump was installed. The rough idle remained after the first pump was replaced. Next, the car experienced power loss and the CEL light came on. The car just had the MAF replaced and another fuel injector pump installed. (Don't know if symptoms went away as I have not seen the car yet.)

My questions are, is this a common problem with these cars? And, if anyone else has had this pump replaced, roughly what was the cost of the part?

Thanks in advance.
 

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E320/E250 Bluetec Ford F350 6.7l
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36,312 Posts
Those diesel injector pumps are famous for outlasting the engines, while engines are like 700,000 miles rated.
On the other hand US mechanics are famous to push the owners into replacing, or rebuilding pumps instead of replacing few old O-rings.
Try to think about it. O-ring cost cents, pump thousand of dollars. What will bring better commission for the mechanic?
 

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1959 220S cabriolet, 1983 240D original owner, 1999 E300 turbo diesel, 1988 560SL, 2003 SLK320
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3,513 Posts
What Kajtek said. The injectors pumps almost never have to be replaced, but these things are known leakers, more so now it seems with ULSD fuel. Many including me are going to viton O rings - we'll see if that's the solution. Rough idle and power loss are the classic symptoms of air getting in the system from leaking O rings.

Len
 

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2000 ML430 SOLD, 2007 BMW 328i Coupe, 2014 BMW i3
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Discussion Starter #5
Thanks for the replies. I think your theories make perfect sense. It'll be interesting to see if this happens again.
 

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1998 E300 TD
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4 Posts
Injection pump rebuild

Ok, so you guys are saying to replace the O rings, however that's not the issue I personally have. Fuel is leaking out of the cover plate under the elctrohydraulic shut off, from the base of the fuel pump and from the bottom of the pump :( Has anyone else experienced this? I'm also getting air bubling up from the fuel pump line. I've replaced almost all of the plastic fuel lines, however some I cannot find. Does anyone know where I can find the gaskets for an inection pump? I really don't want to buy a new one, but without finding the gaskets, I have now choice :(:(:(
 

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1959 220S cabriolet, 1983 240D original owner, 1999 E300 turbo diesel, 1988 560SL, 2003 SLK320
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3,513 Posts
Ok, so you guys are saying to replace the O rings, however that's not the issue I personally have. Fuel is leaking out of the cover plate under the elctrohydraulic shut off, from the base of the fuel pump and from the bottom of the pump :( Has anyone else experienced this? I'm also getting air bubling up from the fuel pump line. I've replaced almost all of the plastic fuel lines, however some I cannot find. Does anyone know where I can find the gaskets for an inection pump? I really don't want to buy a new one, but without finding the gaskets, I have now choice :(:(:(
I think there is no way that you need to replace, rebuild or reseal your pump. If you haven't found all of your fuel hoses and O rings, then find them and replace them. That's almost 100% likely to be your problem. There's an O ring on the fuel hose going to the back of the fuel pump that can make it look like the fuel leak is on the bottom. There's also an O ring on the fuel shut off unit on the pump. I don't think I've ever heard of someone having to reseal the gaskets on the pump itself.

Len
 

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2005 E320 CDI 230k
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18 Posts
I have three E300 diesels (97,99,99) and never had a problem with an injector pump yet. I burn B99 biodiesel in my 99 and it runs like a dream and smells like McDonalds! Once you replace all the o-rings and all the clear fuel lines and delivery valve washers and seals with Viton seals on the 606 engines you will usually never have a fuel concern again. All the lines and washers are available at the MB dealership. You can get everthing else online.

Just remember, DIESELS RULE - GAS DRUELS !

Ringer
 

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1998 E300 TD
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4 Posts
I think there is no way that you need to replace, rebuild or reseal your pump. If you haven't found all of your fuel hoses and O rings, then find them and replace them. That's almost 100% likely to be your problem. There's an O ring on the fuel hose going to the back of the fuel pump that can make it look like the fuel leak is on the bottom. There's also an O ring on the fuel shut off unit on the pump. I don't think I've ever heard of someone having to reseal the gaskets on the pump itself.

Len
Wow, that's awesome that you think there's no way, but guess what...way. I've replaced all the dumb O-rings, all of the lines and the lifter pump (on side of injection pump) since the spring had worn down on that as well. all of this at 120k mi. wait..there's more...the INJECTOR PUMP IS LEAKING!! Despite so many people's optimism that replacing o-rings fixes every problem anyone has with these vehicles, it's not true. The pump is leaking at the retainer bolts where the injector line goes into the top of injector pump. Has anyone fixed this? I'm sure I'm not the only one who's had this go bad.
 

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1959 220S cabriolet, 1983 240D original owner, 1999 E300 turbo diesel, 1988 560SL, 2003 SLK320
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3,513 Posts
Yep, delivery valve seals. Cheap and not too bad to DIY. I still stand by my statement that the injector pumps are not unreliable, but they can leak. Fix it for ten bucks rather than replace it for a couple of thousand. What is there to lose?

Len
 

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1998 E300 TD
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4 Posts
Yes, that is what are leaking for sure :) I have the "all data DIY" subscription, however it does not list parts, nor instructions on how to fix. Recomendations?
 

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1997 E300D
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71 Posts
I have a 97E300. My pump is leaking oil from the cover that oring 152 is supose to seal.
I cleaned everything off the entire engine with simple green. THe oil leak is coming from this seal. I then discovered the torx screw is missing in the upper Left. I went to MB and they don't carry the torx bolt. Where can a get this bolt? I bought the seal from MB for $21. I may just try to install the bolt and torq all of them down. Anyone know the torq spec? I also have a oil leak out of the oil level sensor. It's not leaking out of the 0-ring seal, its passing through where the sensor conductor plastic piece comes through the metal
 

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01 VW Golf TDI/ 97 E300
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6 Posts
Do yall know of anyone or anywhere that I could buy a used or re-manufactured pump from? The idiots at the local Mercedes dealership over-torqued mine and cracked the housing, proceeding to patch it with an epoxy of some sort and neglecting to tell me about any of it.
Please help
 

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E320/E250 Bluetec Ford F350 6.7l
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36,312 Posts
Welcome to the forum tusc and sorry for the circumstances.
MB dealers sell remanufactured parts and that is where I would start. Duval is a dealer that offers Internet prices much lower than over the counter prices.
I am afraid that with those pumps outlasting the engines there is not much market for the rebuilders. Would you consider one from junk yard? I wouldn't. Too much work involved not knowing the condition of the pump.
 

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1959 220S cabriolet, 1983 240D original owner, 1999 E300 turbo diesel, 1988 560SL, 2003 SLK320
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01 VW Golf TDI/ 97 E300
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6 Posts
Than if the dealer broke the pump, why you have to worry about it?
Hit the manager or MB hotline.
they refuse to take responsibility for it, although up to that point it had never been serviced anywhere else. but I made the mistake of taking it to an ignorant hillbilly mechanic, being dissatisfied with the dealer's service, and when he reinstalled the pump, after I got it back from being rebuilt, the crack that the dealer had patched (part of the flange that mates to the block) re-cracked and now it leaks oil.

Before I even took it to the hillbilly mechanic I did take the issue to the manager, but like I said she said they didn't do it. But I gave up on going that route, as they are one of those service departments, and she one of those managers, that you have to "tip" quite heavily to receive anything close to what most would consider acceptable service.

I'm assuming that by having someone else work on the car when it "re-broke" I screwed any chance of the dealership being held responsible.

Any suggestions?
 

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E320/E250 Bluetec Ford F350 6.7l
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You can always take the stealership to small claim court what cost less than $50.
Having records of service and the hillbilly written statement that the pump was patched when he started the job makes good claim.
If the hillbilly has no business license that can be harder.
But pump replacement goes fast into 4 digits.
What was the stealer performing on the pump when they broke it?
 
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