Hi guys, have a question.

My gauge is showing hot on my 77 450SEL, but the system seems fine. That means there's a good chance my gauge is wrong. Three mechanics have said they think the cooling system is fine.

So I figured the first place to start is with the water temperature sending unit.
The problem is finding the little sucker.

I have a pic w/ some of the little gadgets labeled. For those of you w/ access to the Haynes manual on the 350 and 450 cars, I am trying to take a pic of the same angle and parts as is shown on page 94.

Here's the pic:


If I am correct, then #1 is the cold starting valve, #2 is the idling speed adjusting screw, #3 is the supplementary air valve, and #4 is the water temp sending unit to the gauge.

On the down side, I am not able to locate the thermal time switch on my car (which could also be #4), and the unit I am identifying as the water temp sender (i.e. #4) is a 2 prong unit.

The MBz part number is 005 542 2617. When I went to the shopforum parts site, I got part P4036-12281, which shows a 1 pole terminal.

Before I order the part, I'd like to make sure that a) I am ordering the correct part for my car, and b) that I know where to screw the dang thing in when I get it.

I'm hoping that one of you guys has replaced the water temp gauge sending unit on a M117 engine and can tell me if I'm right in my location, or if I'm wrong, tell me where the sender actually is located.

__________________
Love driving my '77 450 SEL!
124,000 miles

http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=116033&M=117983&GA=722%2E001004&L=765%2E702&VIN=%2A&CT=M&cat=043&SID=01&SGR=065&SGN=07
must be it,the part n-r is the same.
Actually,type your VIN here:
http://www.detali.ru/cat/oem_mb.asp
,go to engine husing,then cylinder head/gasket,it`s n-r 77
the sender is used on many modes(gasoline,diesel) and @ 90cCelsius the sender should read 51+/-4 ohm resistance. You may want to check it with a multimeter first.Yes,it`s a one pole sender.
Look here:
VDO corresponding number:
323801020002D
http://www.inodetal.ru/cat.php?catid=VDO&page=1
and the VDO senders page:
http://www.kienzle.de/uploads/media/sensoren_instrumentierung.pdf
Good luck.Check it first and clean the contact points(cable shoes etc.).

On the M116 & M117 motors, the temp gauge sensor is at the back of the motor on the same side as the oil filter, but inboard of the V. It screws into the head. Resistance in the wiring is a possible source of the trouble.

If you had a spare guage cluster as well as a spare temp feeler, you could isolate out which of the three components is faulty.

-CTH

__________________
- cth350@gmail.com
http://www.111lakeside.com/

Do yourself a favor and throw that trash Haynes manual out. Buy the Mercedes CD, you'll never look back.

__________________
Question Authority before it Questions you.

Thanks for your assistance, guys. That Russian site is pretty darn awesome; I'll save it for future reference. Too bad that it's not in English (or that I don't read Russian!).

I'm about to head out of town for a couple of days, but I wanted to say "Thanks a bunch!" Your suggestions will help me pinpoint what's going on.

As for the Haynes manual, as incomplete as it is, I think it's actually more detailed than the Chiltons! I have a MBz cd, but there are plenty of times that it leaves something to be desired (for instance, I don't have a search function that would give me "index" capability). I also may not have the "best" cd, but I don't know if there's more than one out there.

I'd buy the shop manual for the M117, but so far I haven't seen it at anything even faintly resembling a reasonable price!

Appreciate the quick assist,
Mike

__________________
Love driving my '77 450 SEL!
124,000 miles

http://www.startekinfo.com/StarTek/outside/7239/images/Alpha.pdf
http://www.startekinfo.com/StarTek/outside/7239/images/Numerical.pdf
http://www.startekinfo.com/StarTek/outside/7881/?requestedDocId=7881
http://www.mbusa.com/heritage/index.do
on the last,go to "classic centre">"technical literature".It list service CD`s 19$,when were sold for 130$,The Early Model Years for example...I do not know which one of the price lists is valid ,but 19$ is a damn good deal(.pdf files of factory manuals,actually)..





Your search has returned the following results: 7 items

--------------------------------------------------------------------------------

Model Year 1977
Model 450SEL
Chassis 116.033
Engine unspecified


--------------------------------------------------------------------------------





Technical Data Books are intended for technicians familiar with the maintenance of Mercedes-Benz passenger cars. It contains excerpts of the most important data and adjustment values. Technical Data Books include information about capacities, operating materials, dimensions, weights, measures and tolerances, settings, performance curves and much more. Technical Data Books are approximately 400-600 pages in length.


Part Number Part Name Medium Unit Price Quantity
QL-6510-1270-02 Edition 1980: Passenger Cars ... print $54.99
QL-6510-1271-02 Edition 1981: Passenger cars ... print $29.99





Owner's Manuals cover a great deal of useful information that allows a driver to familiarize themselves with a vehicle. Specifically, they give information about the operation and service of a specific vehicle. It is imperative that every vehicle contains an Owner's Manual, because instructions and warnings that are included in these manuals provide for greater safety and longer service life of the vehicle. These manuals are approximately 25 to 125 pages in length.


Part Number Part Name Medium Unit Price Quantity
QL-6510-4951-02 280 SE / 450 SEL; 1977 (Repro... print $19.99
QL-6510-9089-02 280 S/SE/SEL - 350 SE/SEL - 4... print $43.99





Maintenance Booklets serve as the documentation and notation of maintenance performed on a vehicle. Use them to demonstrate your proper upkeep of a well maintained vehicle. These booklets are roughly 25 to 125 pages in length.


Part Number Part Name Medium Unit Price Quantity
QL-6510-9211-02 280 S/ SE/ SEL - 350 SE/ SEL ... print $19.99





Service Manuals act as a detailed guide to the vehicle. They contain descriptions of all important assembly, adjustment and inspections to be performed. Pertinent data, dimensions, and tolerances, as well as special tools for various individual operations are listed in separate tables. Service Manuals also give repair instructions in detailed steps assisted by drawings, photographs and charts. Service Manuals include information on both the engine and the chassis of a specified vehicle. They vary in size from approximately 400 to 1200 pages in length; however, Service Manual Supplements are generally less than 400 pages. Some Service Manuals may also be offered as a CD-ROM.


Part Number Part Name Medium Unit Price Quantity
QL-6516-5600-02 CD-Rom W116 Service Manual Li... CD-Rom $19.99





Wiring Diagrams include basic information about the wiring of a specified vehicle. They are one page schematic diagrams of the electrical wiring and component locations for a specific model.


Part Number Part Name Medium Unit Price Quantity
QL-6540-3504-02 450 SE/SEL; 1977 print $2.99

Thanks a lot. I found the gauge.

Here's a picture for all future gauge seekers.

http://img178.imageshack.us/img178/1382/img2630ahz8.jpg

Thanks also for the info on technical manuals et al, vox incognito. I appreciate it, and will start tracking down what I don't have.

__________________
Love driving my '77 450 SEL!
124,000 miles