E300TD diesel collected in injector wells - PeachParts Mercedes-Benz Forum

m1tch · #1 04-17-2015, 01:11 PM

Hi all,

I have just picked up my E300TD, just going through it and there seems to be some diesel in the injector wells of 4 of the 6 cylinders, the diesel is darker yellow and the well at the back is black - this makes me think that its an old problem.

Would it be a case of the hardpipes needing to be torqued down a bit more or are there copper gaskets under the injectors that might need replacing?

I have removed the diesel that had pooled and will check again once I do a few more miles in it, I would say there was about an inch in there, perhaps its just leaked over time if its been sat at some point?

Is this a common issue with the hard pipes or injector seats? The car idles fine though and has power.

vstech · #2 04-17-2015, 01:15 PM

we'll need a bit more information...

what year is the vehicle?

what exactly do the rear badges say?

I'm unfamiliar with an E300TD... is this a wagon? I'm guessing a W210 98 sedan... but it's just my guess.

m1tch · #3 04-17-2015, 01:17 PM

Uk spec W210 turbo OM606 estate (wagon), sorry for the lack of initial info - Its a '97/'98 E300 turbodiesel.

tjts1 · #4 04-17-2015, 01:19 PM

Quote:

Originally Posted by m1tch

Hi all,

I have just picked up my E300TD, just going through it and there seems to be some diesel in the injector wells of 4 of the 6 cylinders, the diesel is darker yellow and the well at the back is black - this makes me think that its an old problem.

Would it be a case of the hardpipes needing to be torqued down a bit more or are there copper gaskets under the injectors that might need replacing?

I have removed the diesel that had pooled and will check again once I do a few more miles in it, I would say there was about an inch in there, perhaps its just leaked over time if its been sat at some point?

Is this a common issue with the hard pipes or injector seats? The car idles fine though and has power.

Since you have a 97 E300 Turbo Diesel estate in the UK (an engine/body/year combo never sold in the new world) you should add your location and model to your signature to avoid further confusion.

I would soak up all the existing fuel in the wells and then replace the thin rubber return hoses in between the 6 injectors. If it still leaks after that, then you'll have to rebuild the injectors.

m1tch · #5 04-17-2015, 01:20 PM

Quote:

Originally Posted by tjts1

Since you have a 97 E300 Turbo Diesel estate in the UK (an engine/body/year combo never sold in the new world) you should really add your location and model to your signature to avoid further confusion.

I would soak up all the existing fuel in the wells and then replace the thin rubber return hoses in between the 6 injectors.

Will do - I wasn't aware until yesterday that most of the US guys only had the slow E300 N/A!

Do you think its simply a case of those return hoses leaking slightly and nothing else?

Thanks for your quick comment - its put my mind to rest a bit, was worried I needed to start pulling injectors!

tjts1 · #6 04-17-2015, 01:26 PM

Quote:

Originally Posted by m1tch

Will do - I wasn't aware until yesterday that most of the US guys only had the slow E300 N/A!

Do you think its simply a case of those return hoses leaking slightly and nothing else?

Thanks for your quick comment - its put my mind to rest a bit, was worried I needed to start pulling injectors!

Yes, its very likely. Like all rubber components, those hoses degreade with age. You can buy new fuel return hose by the foot for very cheap, cut to length and replace it ALL of it at the same time. Be sure to get hose that has the same pleated outer layer. Identical hose was used on numerous other cars with mechanical injectors, not just MBs. VWs, Peugeot etc come to mind. Any auto parts store over there should have it in stock.

Theres a slight chance that the hoses are not the probem. Instead fuel could be leaking from in between the lower and upper halves of the injector in which case you would have to rebuld that injector. Thers also a chance it could leak from the hard line connection at the top of the injector but again, its less likely than the hoses. With a 14mm wrench loosen then retighten the connection. Don't over do it.

good luck

m1tch · #7 04-17-2015, 01:35 PM

Quote:

Originally Posted by tjts1

Yes, its very likely. Like all rubber components, those hoses degreade with age. You can buy new fuel return hose by the foot for very cheap, cut to length and replace it ALL of it at the same time. Be sure to get hose that has the same pleated outer layer. Identical hose was used on numerous other cars with mechanical injectors, not just MBs. VWs, Peugeot etc come to mind. Any auto parts store over there should have it in stock.

Theres a slight chance that the hoses are not the probem. Instead fuel could be leaking from in between the lower and upper halves of the injector in which case you would have to rebuld that injector. Thers also a chance it could leak from the hard line connection at the top of the injector but again, its less likely than the hoses. With a 14mm wrench loosen then retighten the connection. Don't over do it.

good luck

Many thanks, I am just in the process of going through the car anyway as I know at this age there will be some degrading of rubber parts. The car has been keep to a very high standard, I guess these return lines are rather hidden under the plastic cover so can easily be missed.

It might be a case of the injectors needing to be rebuilt, the car is on fairly high mileage, not really an issue though as its probably quicker to recondition them than it is to try and clean then whilst still installed!

Maxbumpo · #8 04-17-2015, 01:52 PM

Quote:

Originally Posted by m1tch

It might be a case of the injectors needing to be rebuilt, the car is on fairly high mileage,

Doubtful, either the injectors leak immediately after a rebuild, or they don't and probably never will.

There are really only two places to check, the aforementioned rubber/cloth return lines, and the hard steel lines. If the return lines are not the issue (and they almost always are), then you may have loose connections at the injector top hard steel line, or the steel line itself is cracked and leaking. If the steel line holders (plastic clips) are broken or missing, then sometimes steel lines rub together and wear holes. However, a problem with a steel line will almost always result in a poor running engine.

m1tch · #9 04-17-2015, 02:00 PM

Quote:

Originally Posted by Maxbumpo

Doubtful, either the injectors leak immediately after a rebuild, or they don't and probably never will.

There are really only two places to check, the aforementioned rubber/cloth return lines, and the hard steel lines. If the return lines are not the issue (and they almost always are), then you may have loose connections at the injector top hard steel line, or the steel line itself is cracked and leaking. If the steel line holders (plastic clips) are broken or missing, then sometimes steel lines rub together and wear holes. However, a problem with a steel line will almost always result in a poor running engine.

Sounds like its the return lines then, as its 4 out of 6 injectors I doubt that it would be hardlines on all of those.

I am guessing they are just a push fitment? Might even be the case that they have been replaced at some point but they didn't bother removing the diesel that did leak!

jay_bob · #10 04-17-2015, 02:06 PM

I had this problem

If its fuel, it's either the return lines (easy) or the pressure lines (worse due to availability and cost). If the pressure lines are not properly supported they can fracture and fail.

You could also have oil, this engine has 7 valve cover gaskets, 1 ring at each injector, and the big one around the perimeter.

See this thread: http://www.peachparts.com/shopforum/diesel-discussion/341600-attn-om606-inspect-under-engine-cover.html

andrewjtx · #11 04-17-2015, 02:08 PM

Yeah, my money is on return lines. I miss the simplicity of the OM617 in that regard. At least on the turbo OM606 you don't have the crossover pipe you have to remove to do just about everything...

jay_bob · #12 04-17-2015, 02:12 PM

Just saw your reply at 14:00, yes the return lines are push fit.

However, you do need to be gentle with the removal. It is possible to be too rough getting them off and crack the fitting. Or if you are tempted to score the hose to remove it, that can put a scratch on the fitting that creates a leak. Best to grip the hose with a pair of needle nose pliers (put some electrical tape on the jaws so that there is no chance of scratching the fitting) then grip the hose and twist back and forth to break the bond.

tjts1 · #13 04-17-2015, 02:34 PM

Quote:

Originally Posted by andrewjtx

Yeah, my money is on return lines. I miss the simplicity of the OM617 in that regard. At least on the turbo OM606 you don't have the crossover pipe you have to remove to do just about everything...

On the NA 606:
Cut the plastic injector cover in half right underneath the cross over pipe. That way you'll have easy access to 5 of 6 injectors and you can at least inspect the 6th without removing the cross over pipe

jay_bob · #14 04-17-2015, 02:51 PM

Quote:

Originally Posted by tjts1

Cut the plastic injector cover in half right underneath the cross over pipe. That way you'll have easy access to 5 of 6 injectors and you can at least inspect the 6th without removing the cross over pipe

That's only necessary on the N/A 606. Turbo 606s are intercooled so there is no cross over pipe. The entire cover comes off easily in one piece.