Oil pressure & RPM gauge

[Cortez-Campos]

Yesterday my oilpressure gauge and my RPM gauge stop working suddenly, they have worked for the last 2 years with no problems, but yesterday they both went to zero, all other gauges work perfect.
I got very affraid so I checked the oil level, but there where plenty of oil, and the engine sounds great, no problems what so ever.

What are the link between those 2 gauges ?? do I need to be affraid? or is it something simple?


I X my fingers )

Christian Cortéz-Campos

280 SL 1969 anthracite 172, with red inteior.

[Tom]

Did the car continue to run?  This sounds pretty serious, as the mechanical tach (RPM) gauge pickup is linked to the oil pump drive shaft.  The oil pressure pickup comes from near the oil filter canister.  So for both not to work simultaneously (i.e.you are getting no oil pressure and no RPM), it is likely that your oil pump is not functioning and you should not start/drive the car as the engine will quickly seize.

Additional thought-it is also possible that connections behind the dash are loose (seems unlikely-is there oil dripping down from the dash?) or that something in the gauges at the dash prevent both from functioning.  However, what seems most likely is what I described in the first paragraph above.

1971 280sl Tunis Beige Metallic (restored & enhanced)
1971 280sl Tobacco Brown (low mileage stock)
1970 280sl Medium Metallic Blue Beige Interior (project car)

[Cortez-Campos]

yes the car continued to run. I had 2 miles home and I left it in the garage, today I started it up, and it sounds normal, I also went for a 3-4 miles drive, and there are no problems.

How can I check if the oilpump is functioning?? normal the oilgauge is at top, so I guess the oilpressure normal is OK.

280 SL 1969 anthracite 172, with red inteior.

[Naj ✝︎]

I have to agree with Tom

Investigate and be sure before you drive the car again.

Check on items in these topic and similar:

http://index.php?topic=443&whichpage=2

http://index.php?topic=3097,bush

naj

68 280SL

[ja17]

Hello Cortez,

Sounds like a worn "vertical timing gear" and or the "aluminum bronze bushing"  are allowing the oil pump to disengage. It is critical that you remove the tachometer cable at the engine and remove the aluminum and bronze bushing and the vertical timing gear to check them for wear.
Download Attachment: removal of verticle gear.JPG
60.1 KB
Search up the information on this site or ask for more information. This is very serious!!!  It seems that your problem is intermittent but it will not last. You may loose your engine if you  do not look into this. I would definately not drive it.

The oil gauge is mechanical and seldom fails.

Joe Alexander
Blacklick, Ohio

[Cortez-Campos]

I have allready placed it in the garage, and tomorrow I will get it to my mechanic.
Thanks for your advices, I will bring the photos and your advices to my mechanic







Christian Cortéz-Campos

280 SL 1969 anthracite 172, with red inteior.

[Cortez-Campos]

Here are my worn verticle gear, I have forgot who asked, but here you can see them, and they are very bad ( and very expensive )

Download Attachment: WORN GEAR.JPG
20.26 KB




Christian Cortez-Campos

280 SL 1969 anthracite 172, with red inteior.

[Raymond]

But much less expensive than a new engine.

Ray
'68 280SL 4-spd Coupe

[rwmastel]

That big thrust bushing can cost a few bucks, too.  I hope you don't have any significant engine wear from this.  While you're at it, have your mechanic make sure your oil filter housing has the thick top seal in it.  This seal is like a 3/4 inch section of garden hose and it should be stuck up in the filter housing.  Without it, you're not filtering oil.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[Cortez-Campos]

I am actual thinking of a full restoreration of my engine, last winter I did the paint, crome and the interior, so now I am only missing the engine, my plan was that I would wait a few years with the engine, but now this happen, so why wait???

It will be very very expensive, I have heard there are a someone in Norway and in Germany which does this work for around 10.000 Euros.

But I keep thinking that it is a great car, and I don't think it will be less worth, and this month it turn 37 years old, so let's look forward towards the next 37 years )

Christian Cortez-Campos


280 SL 1969 anthracite 172, with red inteior.