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.
__________________ 2000 ML430
Chrome grille, tailgate latch, logo on rims, instrument cluster rings - K&N air filter - Ate brakes - projector style lights w/xenon bulbs - white LED lights on licence plate - handpainted pinstripe - designo Java Shift Surround - brushed aluminum roof rails
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?
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.
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
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.
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
Last edited by DIESELRINGER : 03-08-2008 at 02:01 PM.
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.
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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