I have a W140 with M104 engine.

I have a, what I suspect, a injector leak as the #5 injector have black oil all around the outside (just by looking) while all others are just dust.

I will properly get a mechanics to replace the injectors as its a 1992 car. However I read that there are other plastic, housing, hose, vacum that should be replaced as well.

Can someone explain what I need to tell the mechanic to replace?

Any idea of cost?

Thanks

Don't take this the wrong way, but shouldn't you take your car to a mechanic who doesn't need to be told?

Sixto
91 300SE
87 300SDL
83 300SD

h_shek,

If an injector was leaking, you would have clean oil around it. Black oil sounds like engine lubrication oil and would be leaking from someplace else.

To replace the injectors just because the car is a 1992 is a poor idea. Does the engine run OK? If so, the injectors are OK. If you are really worried about the injectors, have them tested at a Diesel injection shop.

If you didn't find the oil leak, would you even think about replacing the injectors? You sound like you don't know much about MB engines so maybe you should let your mechanic do the diagnosis.

I have '79 and '80 MB Diesel cars and I wouldn't think of replacing the injectors on a whim or an oil leak. IF IT AIN'T BROKE, DON'T FIX IT.

Investigate the oil leak. It may be just a leak in the valve cover gasket.

P E H

a '92 300SE, I believe. Gas engine, etc.

Why did you post in "Diesel Discussion"?? Wouldn't a post in the "Tech Help" section been better?

Please describe the car's symptoms, if any? To replace the injectors because of "black oil" is not recommended.

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

Hagies thanks for your reply. Truely value your help in this regards.

Jim, thanks for your note. Yes without you pointing the point out, I didn't realise I posted in the wrong board. Mine is a "Petrol" engine and thanks for correcting me in this regards. Still running very HAPPY with your excellent cool harness.

What Hagies point out is true, I properly should't replace things because of its a 1992 car. In fact I don't seem to have any of the "Bad Injectors" symptom as discussed in detail in this web site. My idle speed is around 600 rpm and I don't get any vibration nor any hestitation. (I think these are the symptom)

In fact I found this "so called" leak from visual inspection rather than idle hestitation or poor start problems.

Out here where I am, the mechanics will always say "replace the lot" I wanted to get some opinions from expert here in regards to what really should be replaced. I hate to replace something that does not need replacing at all. Worst still, the mechanics will charge $$ labor with no value add!!

OK my problems?? just a visual leak, I think. One of the injector, #5, has black oil all around it and in areas near-by including the harness connection. I am worried that this may lead to bigger problems and thus want to get a mechanic to fix it ASAP. Should I not worry? How involve is this? Should I post a picture?

All help are greatly appreciated. Thanks to all of you!

get some BRAKE cleaner rather than CARB cleaner, and spray everything around your injectors.

Give your car a good 'cleaning' and remove the accumalated grease/oil. Then let it dry and see what happens.

CARB cleaner has negative effects on rubber parts so that's why I suggested BRAKE cleaner.

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

Jim:

Thanks for your reply.

I am sure the grease/oil is rather new so i am sure its some kind of leak from somewhere. I look at my engine every-now-and-than, and its very obvious to have a huge wet/grease spot. Even obvious if the all other injectors looks the same while this one is all wet.

While I agree cleaning it and see if further leaking will happen, I really think something is not right there. In anycase, I have booked a time with my mechanic tomorrow to have it looked at. I guess the deal is, DO NOT REPLACE INJECTORS. Thank you for letting me know that and properly saved me 200 bucks..

I will get some break cleaner and spray on it... Jim I remeber your site recommend tyre cleaner for the engine compartment. Since I am going to spray things on the engine, should I use break cleaner all over the engine or just that injector area? Should I still use tyre cleaner?

Thanks

that you can 'watch' the area in question to see what it is and where it's coming from.

Usually injectors leak internally and can cause rough running, etc. But if your car is idleing and running ok, I wouldn't change anything until you know it's bad.

As far a applying some tire cleaner, I wouldn't do that until the 'leak' is resolved.

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

Ok..

Took my car to the mechanics and here is the initial assessment.

He told me that under the fuel injector there are plastic housing that attach to it. (Sorry I cannot be specific because I live in a country where english is not the native language and I am trying to translate what he explained to me).

The problem is, that plastic is crack and leaking oil. The mechanics said the stuff I am seeing is not grease but rather petrol. He said there is a safety concern that the engine may catch a fire.

Now is he lieing? I don't think so since he suggest me not to fix it as in order to fix it, its very involved. He said he needs to open the engine, exposing the interior cylinders and have it replaced. Worst still, with the age of my car, he said there is a risk that when he remove injectors (appreantly, all 6 must be removed at once) plastics attached to other 5 will also crack as a result. This will lead to me replacing all 6 rather than just 1. It will cost me around 1200 USD to replace all 6 including labour.

He said leave it and watch if it get any worst since I am not getting any hestitation problems. However he warn that there is a risk of fire as those are petrol coming out and he said to me be very careful.

My view, have it changed. I do not want to risk a fire in my car. Although the 140 dosen't worth much nowadays, (over 10 years old!!) I still don't think risking a fire is wise compare to USD 1200 investment.

Any comments folks?? Anything else I should be caution while the engine is open? or should i really drive and risk a fire?

H_shek,

You are talking about a gasoline engine (petro). How bad is the leak? Gasoline will evaporate from a hot engine immediately, so there should not much of a build up that would cause a big fire.

It sounds like a scare tactic (fire) to try to get you to spend a lot of money on your car which may not be needed. Can you carry a fire extinguisher with you. They are a lot less that $1200.

I don't know as much about gasoline injectors as I do Diesel, but I can't understand why one injector can't be removed individually without affecting the others. Maybe you should get a second opinion.

P E H

well the mechanic said if I get lucky, when they remove the injection valve, (that metal rod), if none of the plastic housing on all other injectors broke off, I will only have to replace that one.

But if others broke off, than I will have to replace each and everyone of them.

He said at max, I will be charged at 1200 USD. At lowest it will be 400. Lets see how my luck goes...

If each injector cost USD 133 as listed on fastline, its about right, parts along is 800 bucks...

As for fire, thanks for giving me some assurance. I guess I am too worried at times.

cheers

Jim:

Thanks again for your help.

Yes thats what my tech said. The O ring can be replaced as a seperate item. But he is worried that the harness connector on the injectors will break off when he unplug each and everyone of them in order to remove the fuel rod.

As I say earlier, if I get lucky, he will break nothing and only have to replace that 1 injector. Otherwise... going to be a costly excerise for me...

I am praying...

cheers

BTW I mis-understood him. He said onlt the fuel rod needs to be removed, not the engine exposing cylinders as I have said earlier

and here is a pic of the exact injector. as u can see, the horizontal, metal must be removed and he said the plastic will break off due to the age of my car!

Attached Thumbnails

 

a dual rubber o-ring seal on each injector. I've never changed one but recall seeing it on my All-Data CD-ROM.

Don't think there is any 'plastic' except for the "electric plug" that carries the signal to turn the injectors on, from LH-SFI module.

Also they are mounted on a fuel rail that goes around the engine, so it may have to be removed accounting for the 'all-must-be removed' statement from your tech.

I'll check with my tech and let you know what he says.

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page