Another 119 oil tube question
 

The dreaded lifter noise on the 119 engines seems to be more common as these engines exceed 100,000 miles. I have not found definite answers to the following questions in all of the 119 engine oil tube discussions.

1. Are the metal oil tubes that apparently were installed originally in pre 1994 119 engines still available from Mercedes?

2. If available, can the metal oil tubes be used as a replacement for the plastic oil tubes used in later 119 engines?

It sounds like the metal tubes are superior if they can be used.

Thanks!

no, not available. don't know if the old metal will fit in place of the plastic.
i look closely at the plastic ones. some of the "crimps" to hold the little plastic cap are poor so i melt them a bit more to better hold the cap.
also check yer oil pressure. repeated problems point out a bad oil pressure
regulator.

george

kinda a ps to my note. these cars also like to spit out the little
caps that look like freeze plugs that are inserted in the front of the hollow cams so crank the engine over before you do anything if possible to make
sure no oil is poring out of the front of the cams.

george

George,

Thanks for the info.

When you talk about the caps being spit out, are these the ones in the end of the oil tube or is it on some other part?

Any idea on why Mercedes switched to plastic from metal for the oil tubes?

To second mbshop, I checked w/ my tech's part supplier and they are not available. I'm not a 'fan' of the plastic version, but as you have found, they do last about 100K miles. So if you replace them, you shouldn't have a problem for a long time.

On my page, there's a pictorial of how to do it; MENU#19. Also mbshop's idea of securing the ends should just about make them last forever.

I've not done this but a good technique would be to use an hot small tip soldering iron. Then position the tip so that it lays across the body and cap; then touch both simultaneously so that the body and cap start to melt and doing so, weld together. Do this every 120 degs and that should secure the cap nicely.

Good idea but may be overkill.

yes, the little caps at the end. take out the old bad one and its obvious.
yes, might be overkill with the melting bit but new ones are spitting them out also.
they swithed due to cost obviousely. and maybe a few oz of weight.

george

Of course any part can fail but I've personally not seen a replaced oil tube fail prematurely, ie right after it was put in. Maybe it's b/c I do check each part for a solid end cap before it use it. So far haven't found a bad one.

I think you'll find that the heat and oil pressure is the real cause of the cap failure. And further, the 'heat-fusing' idea is probably the best bet to eliminate all failures.

george and Jim F:

Thanks for the helpful responses. I now have one final question. Do you think Mercedes designed the oil tubes with the caps for a reason? It seems like they must have wanted them to serve some purpose, otherwise the tubes could be manufactured without the end cap. Could it have been intended as some sort of pressure relief valve? Whatever the reason for the design, the oil tubes have become a common problem on the 119 engines.

My understanding was that it was a pressure relief valve, made of plastic because the loose end caps would then not do harm inside the engine. True or not I suspect lower cost was a major factor. The 113 motor that followed apparently cost less than half as much to manufacture - so clearly they were thinking the 119 was too costly.

It certainly seems logical to assume that's why the end caps are there; to relieve excess pressure or as a cleanout but here's some interesting facts;
1) The METAL tubes didn't have any relief caps,
2) MB oil pressure is speced up to 6 bar, ie apx 90psi. The oil pressure gauge is ''pegged" at 3 bar but that very fact means that the pressure is higher.

So if the metal tubes did not have end caps, then why put them into the plastic versions? Certainly relieving oil pressure is not the answer.

I think I read that you could use the end caps feature as a clean-out but then would reguire you to replace it afterwards??

So I don't know why the palstic oil tubes have end caps? :confused:

I talked to an experienced Mercedes parts man about the oil tube history. He said they had problems with the metal tubes plugging up but he hasn't seen that happen with the plastic ones. It would seem that the oil change intervals would have to be seriously ignored to plug the tubes. Maybe the plastic is slicker inside.

deanyel: Any idea what damage high oil pressure would cause if it was necessary to design the end caps to blow out? I'm sure cost did play a role in this design since Mercedes was in a price reduction transition starting in 1994. For instance, the 400E/E420 dropped in base list price from $56,400 in 1993 to $51,000 in 1994 and the 1994 model had a number of improvements.