W123-TECH Oil Pressure Gauge - Leak

[koolfrog]

Oil is dripping from under the dash.....of course , I suspect the connection from the line to my gauge ( i would not have thought it was a mechanical gauge) !
Did that happened to anyone ? Did you have to replace the whole line ? any other possible fixes ?

[Gray Poupon]

To get to the oil gauge line take the panel out from under the dash by the steering column. You will want to remove this anyway to clean up the oil. Reach up and push the instrument cluster out. It's a tight spot to reach if you have large hands and arms. Once out you will have no problem finding the source of your leak. If you can't reach up there make a couple of small hooks out of some stiff wire to slip in between the instrument cluster and the padding of the dash to pull the cluster out. Be careful with the hooks though because you can easily tear the dash padding.

[Sokoloff]

COuld also be a vacuum line problem with oil being sucked into the vacuum line that terminates at the ignition switch.

Len

[VLayton]

I had this issue on one car once, have seen/heard of it a few-

I believe this issue usually arises from not using a backing wrench when removing the line fitting- e when removing the cluster, pulling on it too meanly can hurt the fitting on the gauge assembly as well, it can get very fragile with age-

on my car- (one I had never serviced this area on prior) leaked pretty, bad, I discovered one detail day- It was soaking th einside of the cluster assmebly- and got into the light designation cards- I removed the 3 instrument fixtures, cleaned them carefully, and replaced the gauge fixture. I could not get all the oil out of the nooks and cranny of the cluster housing, so I opted to switch it with a spare

No more problem

ALWAYS USE A BACKING WRENCH WHEN UNDOING YOUR OIL PRESSURE GAUGE LINE TO AVOID THIS-- those clusters are expensive!!

Good luck

[H-townbenzoboy]

Forgive my ignorance, but what is a backing wrench?

[Gray Poupon]

A wrench that holds the other end of a nut or bolt. In this case it's the other end of the fitting, the one nearest to the gauge. You can easily damage the gauge by tweeking it using only one wrench.

[H-townbenzoboy]

But you shouldn't need a backing wrench since the fitting closest to the gauge doesn't move, right?

[VLayton]

It's not supposed to move, that's the trouble. Relieving the torque of a sealed connection puts too much lateral force on the fitting mounted to gauge, twisting it if you will. They obviously don't consider the fitting strong enough to not break up the circuit board it's mounted in, that's why it's designed for you to use a second wrench to counter the force one needs to apply. This principle is also used for cooler lines and brake hoses and stuff.

[H-townbenzoboy]

Well, I've learned something tonight. That's good info to know.

[koolfrog]

Thanks for all these answers , so ...do you think I can just replace the tubing or do I have to get the OEM Mercedes line ?

[VLayton]

Are you sure it's the line at fault?

Life while repairing the car is always better with proper parts.

These rarely fail, so I'd get one from a donor car before I'd try to engineer something like that myself- good general MB rule anyway. Easier, more likely to work, etc, etc. Why not just get a nice new oe MB part? It's not like you'll ever need another one barring a freak accident

[koolfrog]

Not sure it's the line....just know it's leakink oil behind the gauge!!!
I am not trying to save a few bucks ...i just did not removed anything yet and am trying to figure out where the leak is EXACTLY coming from ...

[VLayton]

I gotcha, I always say stuff like that. Part of my reason for being is I was tired of seeing rigged repairs.

You'll have to pull it to find out for sure is my guess, I'd say 19 to 1 it's the gauge unit. Remember what I said about backing wrenches, in cause your guage isn't already this issue.

Regards :cool:

[koolfrog]

Where is the best place where to buy the oil pressure line /

[VLayton]

Don't know what supplier may stock it, even Performance Products has only 40% of the parts for the car. Dealer is usually a lock. Scrapyard?

[Maxbumpo]

The Bourdon tube in my oil pressure gauge has a large silver solder patch on it, and there is plenty of evidence of a leak; if it is the tube itself that's leaking, perhaps it can be brazed?

[redgaucho]

Hi, fellas!

Kaiser is a little bit sick again... While troubleshooting a lingering cruise control problem (narrowed down to the amplifier, thanks to tips here and from General Development Labs, http://fix.net/~gdl/testproc.html), I noticed some sooty oil under the dash, and to my dismay, I discovered it came from the oil pressure gauge. The line appears to be fine and it is tight enough. After cleaning up some of the mess (will I ever get it all?), I started the car and drove it a while, noticing that the needle seemed more jittery than I remember...Hmmm... After coming back to the house, I found a very small seep coming from the bottom of the gauge back side, bottom screw. The line and the fitting were dry.

I did some online shopping around for the right OEM part, and found that the folks I deal with have the instrument cluster (coolant temp, fuel qty, and oil press) for anywhere from $284.60 to $328.58, all VDO-Siemens. A used one can be had for $150 from my reliable source, with a 90 day warranty.

WDYT, should I go with a new OEM part, get a used one, or try to braze the bourdon tube of mine? Is the latter even possible? Can one just replace the oil pressure gauge/b-tube assy without messing with the rest of the cluster?

Either way I go with this, I feel some oil dripping on my face already...

Any help from you w123 veterans would be appreciated by this newbie.

Best regards,

[Maxbumpo]

Serge,

All though I've heard many say that it can't be done, on my car ('85 300TD) there appears to be a braze repair to the bourdon tube for oil pressure gauge, and plenty of evidence of a past leak. Find yourself a plumber friend who knows a thing or two about brazing, and give it a shot.

Else, watch on Ebay for a used cluster. $150 for a used gauge is ridiculous, for that price you should be able to get a complete cluster, or maybe even at a lower price.

[VLayton]

Remove the whole assembly, and remove all the gauges. With Q-tips you can clean out most of the oil, do not try to seperate the plexi-glass. Always counter the pressure of the 10 mm line fitting with a 13mm on the female fitting attached to cluster (supporting the fitting in place so as not to apply presure to it when removing and installing.)

Be sure you KNOW the guage you replace it with is for your model, the pin connector configuration varies.

Bummer, good luck. :o

[redgaucho]

Meade and Vince,

Thanks a lot for the replies. I know I can always count on solid advise here!

About the connector pin configuration, what are the differences?

Regards,

[redgaucho]

Meade and Vince,

Once again, you guys saved me some $$$$ with your tips and suggestions! I checked with my friendly indy in Tupelo. He suggested his used part supplier just down the road in Pontotoc, MS (no kidding, really)... The fella came over to the shop with four different 123 (?) instrument panels in different levels of condition... but none matched. He left again to go get the right one, now that he saw mine. While he was gone, Tom let me used his tools and equipment to remove my instrument panel, dissasemble it, clean it, renew all light bulbs, and clean some of the oily mess under the dash. By then, Frank was back with the right 123 instrument panel, and it looked lots better than the others he'd brought earlier, and with only 140k miles indicated. I extracted the needed cluster, cleaned it, swapped bubs, installed, ops ckd and voila, no more leak. I kept the rest of the panel for future use.

So, get this, the "new" instrument panel cost me... (drumroll please...) $38! A lot better than the $150 for just the used cluster that someone else wanted to charge me, or $284 for a new one. And Tom would not take any money for the use of his tools and advice. I already put 150 miles on Kaiser, and no repeats yet.

I would really like to put in a plug for Tom's shop, the Auto Medic, in Tupelo MS. A very professional MB and BMW technician, a good friend and all-around person. If ever near these parts, and need help, call him at (662) 844-9379.

Thanks to both of you guys for encouraging me to DIY and for all the tips (10mm and 13mm, etc) The leak in the bourdon tube was too inaccesible to even try a repair braze.

Thanks again,

[Maxbumpo]

Cool Beans! Glad to hear the happy ending. There is a different forum for recommending shops - you may want to post that information again over there.

$38 is a great price and much more realistic than $150 for just the oil/fuel/temp gauge. I congratulate you on finding such a deal...

[jilly]

I'm the happy new owner of a 1980 300TD purchased on eBay from a local seller and couldn't be happier with my purchase.

I have a question about the Oil Pressure Gauge. Should it move from around one when the car isn't moving all the way up to three (and staying there, steady) when I'm driving?

This is my first Mercdedes, my first diesel and my first "older" car so I don't have a lot of experience to draw from.

I have driving about 200 miles since bringing it home and it drives great, has had an oil change, the oil and fuel filters changed and had some brake work done and the mechanic (same one who's worked on it for years as well as the seller's other vehicles) told me that everything else looked good.

I was on the interstate the other day and noticed what the gauge was doing and wonder if it's normal.

Thank you in advance for any advice you can provide.

As a side note, I've enjoyed reading your forum very much -- in fact, the posts here convinced me I needed to drive something with "character".

[redgaucho]

Congratulations on your new purchase! I too am a first time diesel owner. I bought "Kaiser" in Nov05, and couldn't be happier (see my other posts).

Your oil pressure gauge is indicating a properly functioning oil pump and gauge, from what u say. It should read zero bar while the glow plugs warm up, it should peg up to 3 bar on a cold engine at idle, it should read 3 bar above idle, and once the engine is up to its normal operating temp (85c to 94c, approx) it should read about 1.7 bar at idle. It should always peg above idle.

If u can, post a photo and details of your new Benz. We'd love to hear your story.

Happy motoring!

[jilly]

Thank you for the information. I didn't want to bother the gentleman I bought the car from, although he probably would have gladly answered my question.

I bought "Olivia" (yes, I named her already!) on eBay about 2 weeks ago and she's taken me about 200 miles to date. The seller was selling her as a "parts" car, although she runs fine. He has a couple of other MBs and it seems it was time for Olivia to move on -- lucky for me!

I'll back up a bit --- I have a friend who is very dedicated to living a debt-free life --- as much as one can nowadays. Anyway she is a big fan of Dave Ramsey, who is a personal finance guru of sorts, similar to Suze Orman. To make a long story short, I'm trying to make some changes of my own to better my financial standing going forward and step one was to get rid of my SUV, its payment, thirsty gas tank, and full coverage insurance. So I started to look for a VW Golf, which somehow led me to looking for cars on eBay that were offered in my city. I'd never thought about owning an MB other than thinking that the old wagons were kind of cool-looking. I've heard some things about turning them into grease cars and that does interest me very much (down the road). So I was looking at cars in my area (near Pensacola, Florida) and I happened upon Olivia. I went to look at her the day before the auction ended and was very happy with how she drove, sounded and looked. I'm really not mechanically inclined but the gentleman I bought her from is, and he's maintained her since buying her in 2000. She's gone about 10K miles since 2000. I didn't get too much in the way of maintenance records --- again, the man I bought her from did most of the work himself, and he gave me the name of the mechanic he uses for his vehicles for jobs he doesn't want to do.

I took Olivia in to the shop to address the items the seller told me I should see to, which were an oil change, filters changed, the brakes and the A/C. I ended up needing some brake work on the rear brakes (calipers).

Everything seems to be fine. I have a few little quirks that bother me. For example, I can't lock all the doors. I don't have a radio. And, I can't let the gas drop below 1/4 of a tank.

I'm very happy with my purchase and feel VERY confident on the road, especially on the interstate doing about 60-70mph. Starting and stopping in the city is less exciting, but as I'm looking over at the cars in other lanes thinking about the hefty car payment many of their drivers have -- I'm smiling.

I haven't taken any photographs yet, but here's the link to the auction, which includes a few photos:

Item number: 4631488414
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1,1&item=4631488414&sspagename=STRK%3AMEWN%3AIT

Again, thank you for the information or should I say confirmation that all is well with the oil pressure gauge. I was comparing it to what my gauge does in my "gas" car and scratching my head.

[VLayton]

Welcome to the wonderful world of W123 cars, the greatest secret in automobile pleasure for the buck!

I advise you spend ample time getting to know and love your car before you embark on an often regrettable journey of "grease car conversion" it's not all as simple, easy and cheap as many would have you believe. I think you found a much more sensible automotive solution than any SUV made after 1985 with a gasoline motor, so try to enjoy the real world benfits the car inherinently offers before jumping on the "hippy-trend", (there, I said it!) which I believe will continue to fade and/or increase in regulation until all the "fun" is sqeezed out of it. Have you noticed how many e-bay cars have biodiesel and veggie oil sales pitches? It's a sales line and many of the cars end up back on E-bay in a couple months after reality sets in upon the not-completely-commited. If your MUST relieve an unecessarily guilty enviro-conscience, seek out stations that offer genuine commercial (true biodiesel) and use it only in responsible percentages, I'd say 20% MAXIMUM, but under 10% would be better. Remember, it was probably the societal trend of 10-12 years ago when everyone ran to the dealer for their SUV that got you into the SUV in the first place. Why is it just because the fuel market is screwed up that NOW everyone is supposedly so noble at "saving" the planet? This is a good reason not to jump on trends.

Anyways, sorry for the lecture, I wish you many thousands of happy miles, which we all know are possible if the car is treated right .

Cheers!

[jilly]

Welcome to the wonderful world of W123 cars, the greatest secret in automobile pleasure for the buck!

I advise you spend ample time getting to know and love your car before you embark on an often regrettable journey of "grease car conversion" it's not all as simple, easy and cheap as many would have you believe. I think you found a much more sensible automotive solution than any SUV made after 1985 with a gasoline motor, so try to enjoy the real world benfits the car inherinently offers before jumping on the "hippy-trend", (there, I said it!) which I believe will continue to fade and/or increase in regulation until all the "fun" is sqeezed out of it. Have you noticed how many e-bay cars have biodiesel and veggie oil sales pitches? It's a sales line and many of the cars end up back on E-bay in a couple months after reality sets in upon the not-completely-commited. If your MUST relieve an unecessarily guilty enviro-conscience, seek out stations that offer genuine commercial (true biodiesel) and use it only in responsible percentages, I'd say 20% MAXIMUM, but under 10% would be better. Remember, it was probably the societal trend of 10-12 years ago when everyone ran to the dealer for their SUV that got you into the SUV in the first place. Why is it just because the fuel market is screwed up that NOW everyone is supposedly so noble at "saving" the planet? This is a good reason not to jump on trends.

Anyways, sorry for the lecture, I wish you many thousands of happy miles, which we all know are possible if the car is treated right .

Cheers!

Thank you for the well wishes.
I'm not in any hurry to make any changes other than what's necessary or recommended to continue having a nice smooth worry-free ride. I've driven about 50 miles this weekend and I'm getting use to the differences.

I was driving this evening and my A/C stopped blowing, so that's my next challenge. I just had the the A/C checked out and charged, so I'm hoping it's not a major repair. When I turn press any of the buttons other than DEFROST nothing happens. The fan doesn't come on at all. But when I turn on the DEFROST it does blow and it blows cold if the A/C is on.

If anyone has any ideas for troubleshooting I'd love to hear them.

[Maxbumpo]

Jilly,

Regarding the 'don't let the tank go below 1/4' comment. If this is because the engine will become fuel starved and act like it has an empty tank, there could be several causes.

Most common is when the supply and return line rubber hose connections are reversed in the engine compartment.

Next would be clogged fuel strainer due to microbial growth (water + diesel fuel will allow stuff to grow in the fuel tank).

Another possible cause is faulty fuel gauge sending unit.

Hope this helps.

[Don350SDL]

When I turn press any of the buttons other than DEFROST nothing happens. The fan doesn't come on at all. But when I turn on the DEFROST it does blow and it blows cold if the A/C is on.
That's a classic symptom of a fuse blown, check them (remove them, don't just look!). Other possibilities include a bad ground, no power (wiring), or (unlikely) complete failure of the A/C controller.

Maybe time to buy a new set of fuses, they do age ungracefully.

Don

[jilly]

Jilly,

Regarding the 'don't let the tank go below 1/4' comment. If this is because the engine will become fuel starved and act like it has an empty tank, there could be several causes.

Most common is when the supply and return line rubber hose connections are reversed in the engine compartment.

Next would be clogged fuel strainer due to microbial growth (water + diesel fuel will allow stuff to grow in the fuel tank).

Another possible cause is faulty fuel gauge sending unit.

Hope this helps.

The man I bought the car from told me that a curb had been "backed over" (by another driver) or something to that effect resulting in the gas tank getting pushed "up". This messed up something inside the gas tank (sorry I can't be more specific -- I don't remember exactly the part he referred to). He said that he'd had the gas tank "lowered" (repaired?) and that the problem was still there. If the car goes below 1/4 of a tank it will stop. I am pretty sure it's something inside the gas tank. The mechanic who did my oil change and brake work did look at the gas tank and told me that they couldn't do anything with it with the amount of gas I had in the tank -- I told them that I'd adress the problem in the future and for now just make sure I keep over 1/4 of a tank.

Thanks for the help !

[jilly]

That's a classic symptom of a fuse blown, check them (remove them, don't just look!). Other possibilities include a bad ground, no power (wiring), or (unlikely) complete failure of the A/C controller.

Maybe time to buy a new set of fuses, they do age ungracefully.

Don

Great. I will check this out asap.
Thank you for the troubleshooting help.
I appreciate it.

[Pom Saeng]

I have to replace Oil Pressure gauge on my 1982 3 times.
2 used one and 1 brand new one is still leaking. What `s next ?

[MbZ300d]

i had the same prob on my benz....take and watch for an instrument cluster on ebay....one will come up i got mine for 26 bucks with shipping take a flat head screw driver put it right under the edge of the instrument cluster. push it out a little and the whole thing will slowly pop out disconnect everything and you will be able to take the single gauge out and replace it with the new one you got....most likely the problem is not with the live oil line that is running to the guage it is the actual inside movements of the gauge that are leaking no way to fix it....trust me this is the easiest.....for the time being i would suggest you drive with a small towel on your shins and drive with no shoes.....it ruined 2 pairs of my shoes not to mention stained the aftermarket matts on the floor!!

[brianr]

Meade and Vince,

So, get this, the "new" instrument panel cost me... (drumroll please...) $38! A lot better than the $150 for just the used cluster that someone else wanted to charge me, or $284 for a new one. And Tom would not take any money for the use of his tools and advice. I already put 150 miles on Kaiser, and no repeats yet.

I would really like to put in a plug for Tom's shop, the Auto Medic, in Tupelo MS. A very professional MB and BMW technician, a good friend and all-around person. If ever near these parts, and need help, call him at (662) 844-9379.
Thanks again,

I have a 1982 300CD that needs the gauge. My mechanic says $900 for a new cluster - that must mean all gauges.

1. Is $284 for just the oil gauge and it's mechanism?

2. My mechanic has had 3 delivered used, but all were not matches - is this a real pain? or maybe his source doesn't know what he's doing.

3. if I call your guy Tom, will he know what to send me the first time?

thank you!
Brian

[redgaucho]

Brian,

Ditto what MBz300d said, most likely the leak is from the OP gage's internal mechanism. It's an analog old fashion but usually reliable Bourdon tube coil mechanism, and after 20+ years they are tired...

To answer your q's,

1. The $284 I had found online was for the three gage cluster which includes the OP, fuel quantity and coolant temperature gages.

2. Though very similar, there were minor design differences in that cluster. You would need to specify what yours looks like when ordering. Read my post of 4/26/06, on this same thread.

3. Tom orders his parts like the rest of us, so I'd say it'd be better if you call and explain what you have. I order my parts from several sources. Randy Steele
800-334-2749 / 805-683-4020, www.autopartsguru.com, randy@epsparts.com, is a member here and really knows his stuff. Sometimes I also order from www.autohausaz.com.


HTH,

[VLayton]

All the new replacements for this gauge for all the USA models (except some 1982 and 1983 240D) are one superceeded part. It will not match the other original gauges for a 1982 in design cues, but will work with the system. You would need a good used 1982 300 series gauge to be an exact match. You could find a way to adhere the center silver cap of your original gauge to the new gauge if desired.