I bought this '97 S500 a week ago. When I first drove it I looked at all the gauges while it was idling and everything was good, including the oil pressure at about 2. I test drove it for about an hour and it ran, idled and shifted perfectly. It wasn't until I was half an hour into my trip home that looked down and saw that the oil pressure gauge was at zero. I pulled over immediately but when the car settled down to an idle speed the gauge jumped back up to just under 2. Thinking it was probably a defective sending unit, I started to accellerate and as I did the gauge started increasing until it hit the top and it dropped back to zero. At that point I was sure it was the sending unit so I replaced it with a Mercedes OEM unit. It did not fix the problem.

I have an all data account for this car and found this tech bulletin:



Apparently I need to replace the circuit board. Is this something I can pull out of a salvaged cluster. Does anyone know how to open the cluster up to get at the board?

Baring that, can I install a salvaged cluster without the car's computer system having a bad reaction, like posting a warning on the cluster or refusing to work correctly?

My mechanic tested the oil pressure with a separate gauge and it's fine. I've also taken the car on a 600 mile trip and it ran perfectly, but it sure is scary to look down at the oil pressure gauge and seeing it at zero, plus if something did go wrong I wouldn't know about it until it was too late.

Thanks!

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2000 Mercedes S500
1990 Mercedes 560SEL
1970 Triumph Spitfire

Agree that is seems like the same fault, but have you checked that electric wire all the way up to the cluster? And, since it says that "Ensure replacement circuit board has a production code of 04/92 or higher", doesn't that mean that this tech bulletin is for cars earlier than 04/92?

br,
syljua

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1998 CL500 W140
1984 230E W123

Wow, that's a good point about the date. It just didn't register on me. Since I only have one car on my All Data account I just automatically assumed it only show me data related to it. My mechanic is out of town through the weekend, but I'll pull the cluster to see what I can see.

All the other gauges are fine. It's just the oil pressure gauge that's wacky.

Can I leave the battery connected when I pull the cluster? I'd like to wiggle the connections to see if it has any effect.

I'm also still wondering if I can swap the cluster with a salvaged without there being a problem. There's one close by that I can buy pretty cheap. Does anybody know?

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2000 Mercedes S500
1990 Mercedes 560SEL
1970 Triumph Spitfire

i essentially have the same problem with my 95 e320... one of these days i have to check the connection at he oil filter... i think that's where my issue is....

no issues with the engine, however

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1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


[/SIGPIC]

All the other gauges are fine. It's just the oil pressure gauge that's wacky.

Can I leave the battery connected when I pull the cluster? I'd like to wiggle the connections to see if it has any effect.

I'm also still wondering if I can swap the cluster with a salvaged without there being a problem. There's one close by that I can buy pretty cheap. Does anybody know?

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2000 Mercedes S500
1990 Mercedes 560SEL
1970 Triumph Spitfire

Have you looked at your lower harness? ..also called the positive cable? And you dont need to disconnect the battery to remove the instrument cluster..I might have a curcuit board for a cluster, would you happen to have the part number off of the cluster?

I have done it without a problem! Just make sure the replacement is for your model year. I also swapped out the speedo on the replacement cluster since the mileage on the odometer was about 100k higher than mine! LOL!

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1989 300E

2005 Acura TL

2011 Hyundai Elantra Limited

Swing hard! Take chances!

Unlike a typical oil pressure reading problem, this one really DOES sound like the gauge is the problem. MUCH better than what usually causes a low oil pressure indication. Sounds like maybe there is a flaky connection.

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

Are the other gauges like the tach and clock working OK?

When I had grounding issues with my cluster, the oil pressure gauge would read zero, the tach was a bit haywire and the clock was intermittent. Other gauges were OK.

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1989 300E

2005 Acura TL

2011 Hyundai Elantra Limited

Swing hard! Take chances!

agreed, I would check the connections and wire to the sender itself

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-diesel is not just a fuel, its a way of life-
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