87 300SDL Leak at Injection Pump. Replace seal or whole pump? - PeachParts Mercedes-Benz Forum

jparisen · #1 10-18-2006, 10:52 PM

I have had problems starting my car when it is parked overnight on a hill (nose up) and it seems like the fuel leaks out of the engine. If it is rolled back onto a flat surface it will start. I had it troubleshooted at MB Manhattan and they discovered a fuel leak at the injection pump and recommend replacing it with a remanufactured one (the only ones available I gather). The estimate: $2600

I am not positive if the pump itself is leaking or if it is one or more of the seals. If the pump is in good working order is it possible to replace the seals and not the entire pump?

Hatterasguy · #2 10-18-2006, 11:15 PM

Firstly never, never, never, never, take a 20 year old car to a dealer for such a thing, of course they come up with $2,600.

Now a rebuilt IP should cost about $700-$900, and a few hours on top of that to install. Its not a bad idea if you have the money.

Depending on where its leaking then yes they can be fixed. For example delivery valve seals are quite commen and they cost about $5 to fix if you do it yourself.

jparisen · #3 10-19-2006, 02:53 PM

Thanks for the reply. I know about Mercedes $$$; the facility is so nice though I think I went temporarily insane

. Unfortunately for my wallet I live in NYC with no tools or space so almost all work is done by someone else. I took the car to a friends foreign car mechanic on Long Island and should find out shortly what he thinks. I will probably opt to replace the IP since it is 20 years old at this point and also have the vacuum pump replaced which appears to be original. Is the installation of a "new" IP something that is very complicated and should be done by someone specific or is a decent foreign car mechanic fine? What can potentially get screwed up?

Hatterasguy · #4 10-19-2006, 06:54 PM

If the vac pump is original it is an extremly good idea to replace it! That is money very well spent!

The IP should be installed by someone who knows 603's well, you need an RIV light to time it ect. Not any mechanic can do this, although some get lucky and don't screw it up.

sixto · #5 10-19-2006, 10:41 PM

There are hills in NYC?

Are there visible external leaks? Are they fuel or engine oil leaks from the IP? Check the integrity of the fuel thermostat, that 1.5" x 5" cylinder sitting on the engine mount behind the IP, and the fuel lines that lead around the fuel filter to the cylinder head.

Sixto
93 300SD

Hit Man X · #6 10-19-2006, 11:13 PM

There are about five seals that like to leak... ask me how I know. lol

I think I spent about $11 for them.

ottothegreat · #7 10-21-2006, 12:42 PM

Stop -don't take it to the dealer!! First spend the $50 for the tool and rings (available at the mb parts counter)Then spend about an hour installing new rings,and retorquing to specs.(don't overtighten)Shazzam purring like a kitten once again(may smoke a little at first)It might take a bit of cranking to start it up so dont push the starter to hard or to hot!I'm afraid the dealer mechanics will just remove and clean("remanufacture") then reinstall ip and check for leaks.Shazzam $2500

jparisen · #8 10-21-2006, 03:23 PM

I spoke to the mechanic on LI who looked the car over and asked him about the cause of the leak and the prognosis for the ip. He said that the ip itself did not appear to be leaking but the seals at the fittings (the delivery valve seals you mentioned I gather) are leaking which I did notice were leaking when I looked at it last. The fuel thermostat seems to be fine and the "cigar line" may need to get changed but otherwise the fuel lines seemed ok. Interestingly he mentioned that they found small metal shavings in the pump - could this be general wear or the start of something hideous? I opted to get a remanufactured pump and ordered one from Fastlane for $850 (with core return) and the mechanic will only charge me labor (he thinks 4-5 hours). If anything goes wrong with the installation I guess we could end up in a "it was your pump - not my installation" scenario but I am willing to take the risk. Even with addional expense of the new vacuum pump I should still be ahead of the dealers price for the ip. Just hope it all works out!

sixto · #9 10-21-2006, 03:44 PM

Where did he find metal shavings? The delivery valve opening is really small. Metal shavings would have to be about microscopic to get through.

Sixto
93 300SD

sixto · #10 10-21-2006, 03:45 PM

How did he find shavings in the pump without having the pump off the engine?

Sixto
93 300SD

Hatterasguy · #11 10-21-2006, 06:16 PM

There is no "cigar hose" on the 603. Ask him does he have an RIV light? If so I bet you the timing is off when he installs the new pump.

jparisen · #12 10-31-2006, 09:28 PM

The pump arrived and they put it in on Monday. There are no leaks but I am told the car is smoking heavily (except idle) and power is not great. This is disheartening because it was just about perfect when I dropped it off, no smoking and great power. Does this sound like the timing is off? He does not have an RIV light. I am having a hard time understanding how timing works: is the RIV light method the only way to get the timing correct on these pumps or are there other ways which are OK too? Or could it be something else?

Hit Man X · #13 10-31-2006, 09:29 PM

RIV/AB light is most accurate.

sixto · #14 11-01-2006, 01:48 PM

You can eyeball IP timing and get good results.

There is a static IP timing light that puts a precision around the eyeball method, and a dynamic IP timing light that works kind of like a spark plug timing light.

Since it's all the rage, remove (not just disconnect, physically remove and leave at home) the ALDA temporarily and see if that improves performance.

Sixto
93 300SD