I will check them out.

The chain was rattling a good long time. It was doing it when we got it a few years ago, but we did not drive the car at all untill i got my licence in september. When we took a look at the oil filter to see if it was collapsed there were alluminum bits in it, as you would expect from the chain slaping. So the actual time that WE drove it while it was slapping (it only slaped during the startup because the old CT was the orig, that only had a spring in it, rather than the ratcheting new ones) was only about a month and a half. I have no idea how long the other guy drove it like that.

You only get slap for a second or two at start up, after that the oil pressure will push the plunger against the chain and tighten the chain, it was not bad enough to slap while we had oil pressure, if it gets to that point i think its time to change the chain as well.

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1985 190E 2.3-16v Euro
1980 300GD SWB

Benz,

My concern is that chain slap "usually" damages the chain guides. After about 100k, they are fairly brittle and don't take well to being slapped. The rattle/slapping usually breaks them into pieces that are noticed while draining the oil. The guide pins, steel pins that support the guides, have also been known to be sawed off by the loose chain. These pieces have been reported ingested by the oil pump and tend to get stuck in the screen that protects the pump. Benzmac or MBDoc lost a motor due to a piece working through the screen and into the pump.

I was told if a top chain guide breaks, one can count on the lower guides being broken. I don't know if you can examine your top guide and see if it was ever replaced? I can't recall if it possible to look down the front of the motor with a valve cover off to examine for possible damage? Dan can confirm, it is a total pain in the arse to get at the guides by removing the front cover.

With our car, I found pieces in the oil. The top guide and two lower guides were broken. and a guide pin was cut in half. If I recall this damage probably occured over a relatively short period.

I don't know if something caught in the oil screen would cause your symptoms, but it's something to consider.

Tinker

Ok, sorry i have not been posting here lately, but here is the latest.

I needed a way to get the standard mechanical gauge in the metric hole of the 16v, so i ripped apart the old oil pressure gauge and put some standard threads on the inside of it, so that i could thread that into the car and the oil pressure gauge into it. The hole at the end was to small to be practical (it took way to long to fill the hose with oil) so i drilled the hole out and did it again. The mechanical gauge is telling me the same thing as the electronic one. the oil pressure goes up to around 2bar and will stay there until you step on the gas, when you do that it will drop to about 1.5 bar and will continue to go lower, but i shut the car off at 1.5 bar.

With this information we are fairly confidant that it is a problem with the oil pump and i will probably need to replace it.

Anyone have any other suggestions?

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1985 190E 2.3-16v Euro
1980 300GD SWB

I can't imagine how the oil pump would go bad-i'd pull the pan before the front cover to make sure nothing is blocking the tube. I happen to have a spare "oil pump" from two months ago, you're welcome to it-I pulled it out because I had already bought one, but there was no wear and tear visible after I got the front cover off. The "pump" is actually just two gears (cool design!). Tinker and a few others have had to take their front cover off-all their reccomendations about replacing rails applies, you can also search under my name and find a writeup on removing the front cover.

Could check the blow-by valve before doing anything drastic.

Could even try a second oil filter.

Could try throwing holy water on it.

Dan <===still shakes at the sight of his AC bracket

My father and I were thinking that this may be being caused by a stuck check valve a while ago, and it does make sense... kind of. If its stuck open to a point it will never let the oil pressure go above 2bar, then why would it let the pressure drop farther when you step on the gas? Could it be opening more, and then getting stuck in a more open position? Because the pressure does not return to 2bar after stepping on the gas, and if you shut the car off, then start it up again it will not be at 2bar either, you have to let it sit for a bit...

What is involved with checking the check valve?

Thanks,
Jimmy

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1985 190E 2.3-16v Euro
1980 300GD SWB

Not sure how the check valve operates, so don't want to go out on a limb with a diagnosis, but I could imagine debris in the oil pan causing such a situation. If something is clogging the pipe so it only reads 2bar, with more small stuff that can get sucked into the screen when you rev the engine (thereby increasing sucktion at the intake, but blocking pressure after the pump), you could end up with a screen that blocks more and more oil as the revolutions of your engine increases.

The check valve is on the timing chain cover on the drivers side-low i think. If you don't have a manual-get one, or rather, get as many as you can, many times they overlap.

My 2-bits say you have pieces of guide-rail that broke off after getting *****-slapped by the chain for too many miles. Dropping the pan isn't terrible, and it will let you check for pieces. If you find pieces though, you might want to pull the engine and do the rail-replacement with it out of the car.





cheers,
dan

I replaced the oil pressure sender on my 87 300e this weekend. I found in the MB oem tool kit a short mercedes benz 17mm wrench that fit perfectly into the palm of my hand. All I had to do was push one of the throttle linkages out of the way to get my hand in there under the oil filter, the wrench fit easily onto the nut and it broke loose on the first try. I decided to only hand tighten the new part.

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87 300e (white/black; amg body kit)
88 300ce (red/cream; amg body kit)
93 300ce cabrio (white/blue/blue top)
93 300ce cabrio (black/grey/black top)
98 ml 320 (totaled @ 137,000 miles)
99 clk320 (black/grey/black top)

You must have small hands....

Anyway, Today i took the Pressure relief valve off, and it was a huge pain in the ass. I had to make yet another custom tool. The normal metric alan wrenches from sears (8mm is the size) have a "neck" (the short part) that is to long to get at the screw that holds the plunger and spring in, so i had to cut it down after i went to sears to look for a smaller one with no luck (they were all out of socket ones too). Even then you really don't have enough swing room, when you turn it as far as you can the screw does not turn far enough to line up the alan again. Taking it off i was able to break it loose and use the dirt and foulness on the outside of the screw as a way to unscrew it. But i cleaned it after i got it off, so putting it back in was a huge pain in the ass, BUT lucky for me, while i was at Sears i picked up an 8mm alan with a ball on the end of the long part. You can stick the long part up through a very small gap and use the ball to turn the screw back on, but to torque it down you need to use the real alan.

Now for what happened...

I took everything out screw spring and plunger and cleaned them all in gas. After i noticed that the plunger had a substantial amount of surface scratches on it, is this normal for a car with 133K on it?

But after i put it all back together, i used the mechanical gauge to check the oil pressure, and guess what... 3.5-4bar!!!!! Then i turned it off and on and let it run for a while and then it was down to 2bar. This is still normal and we wanted to change the oil so i took it out for a drive to warm it up, when i got back it was down to 1bar. ****. (before i went out for the drive i did put the electronic gauge back on so i could monitor the oil pressure while i was driving).

We have three theories about what may be going on:
1. Scratches in plunger let oil by
2. aluminum chips or gunk in the oil is now clogging the plunger again
3. Spring is dead (spring that pushes plunger down)

I think it is option 3 because while driving it it was dropping below 1 so i would turn the car off and coast for a bit, then turn it back on and the pressure was up to about 1.5. To me this indicates that the spring can no longer supply enough pressure to resist the pressure of the oil and gradually retracts with minimal oil pressure, which will result in a gradual drop of oil pressure, and when the car is turned off, there is no oil pressure so the spring will push the plunger back down because there is no more resistance.

My father thinks it is number 2, so we are changing the oil and we will attempt to flush it out by running oil through it.

what do you guys think?

(I will get some pictures up at some point of my two latest custom parts)

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1985 190E 2.3-16v Euro
1980 300GD SWB

Ok, here is the deal

I took the car to my Mercedes Mechanic (he does it personally at his house so you don't have to pay Mercedes to do it, if you know him). After about two weeks, he can only work on it on weekends, he called me back to tell me i could come and pick up the car.

Apparently the driver side upper chain guide, not the top one between the sprockets, broke off and fell in to the chain. the chain chewed it up real good before dropping it out the bottom into the oil pan. In the oil pan the chewed up chain guide would get stuck in the oil pump inlet and clog it, giving me my extremely screwed up oil pressure.

We will not be replacing the chain guide because it is somewhat superfluous and requires the head to be removed, which is more than i am willing to do for a chain rail, although next time i happen to pull the head, i will replace it, which i hope i will not have to do for a very very long time.

Jim

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1985 190E 2.3-16v Euro
1980 300GD SWB

I have to give you credit, you hit it right on, nice call.
Jim

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1985 190E 2.3-16v Euro
1980 300GD SWB

I don't get the gold star????????? I guess as much a month before Dan

I don't understand the comment about the head having to come off to replace a chain guide???? I replaced all of mine with the front cover off, but as Dan can confirm it's a TOTAL B*t*h.

Tinker

Well sorry Tinker, i just went from the last post up, i assumed that Dan would have read the rest of the thread and agreed with you...

Tinker wins.

But i will say that was found in the oil, were not pieces of chain guide, so they did not come out in the oil... not the i would know as we cheat and use the pump to change the oil... the chain guide was intact but half of it got mutilated by the chain and looked like it melted, it didn't break off in chunks. The half that melted was all floppy and crap(like a soggy chunk of cardboard), so that half, still attached to the other half, would get pulled into the screen.

Anyway, i just have no idea how to take the front cover off, we looked at the front cover on the 16v that we have the head off of and i didn't see how the hell the front cover came off. I think my father might have seen/ might know how, but it probably looked equally as painful as pulling the head. I will go look at the service manuals that we have kicking around and see how you do it, but it doesn't look appetizing...

Thanks for all the help

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1985 190E 2.3-16v Euro
1980 300GD SWB