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81 300TDT WAGON , 82 300DT SEDAN, 84 300TDT WAGON(retired),
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Discussion Starter #1 (Edited)
Thanks in advance.

I have two questions:
1, will w116 headlight assembly fit W123?
2, Today, I heard some big noise from dash under cluster area, like wa-wa..., it will start after about 1 or two minutes driving from standstill, it becomes louder when accelerating, once brake the car, it is gone.I suspect it is caused by the speedometer pickup connection? or a relay something, or ground issue?
Also when I opened the hood, I found the coolant overflow cap was laid on the top of the tank upside down, the outside of the tank is full of green coolant. I believe that I closed it tight about several months ago. Too much pressure or too hot caused the cap popping off?

Have a good weekend.
 

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2013 MINI Copper S Clubman, '84 300CD-weekend car
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10,152 Posts
The speedo is mechanical, you may want to lube it, or at least make sure it's tightly secured.

As for the coolant cap, I've never heard of that. Is it still operational?
 

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81 300TDT WAGON , 82 300DT SEDAN, 84 300TDT WAGON(retired),
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442 Posts
Discussion Starter #3
The speedo is mechanical, you may want to lube it, or at least make sure it's tightly secured.

As for the coolant cap, I've never heard of that. Is it still operational?
Seems the temperature is only reach about 60-70 degree after 30 minutes driving. Usually it should reach about 100.
 

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2013 MINI Copper S Clubman, '84 300CD-weekend car
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When my thermostat failed, it would not heat up much past 60, a new unit solved the problem.

Will your cap still work?
 

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81 300TDT WAGON , 82 300DT SEDAN, 84 300TDT WAGON(retired),
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Discussion Starter #5 (Edited)
When my thermostat failed, it would not heat up much past 60, a new unit solved the problem.

Will your cap still work?
thank you for response.

I removed lower panel and reached the cluster underneath and found connection of the harness to cluster is loose.
I replaced the cluster with a spare US version cluster(mile). And I drove it this morning and noise was not coming back, but I am still curious of the cause of the noise.

Checked the cap this morning, seems the cap is still tight. But the temperature only reach <60 degree. I am going to order one and replace it. Is it easy to do it? Any gasket or ring required?

by the way, what is the symptom of failure of the auxiliary heat pump? I heard "zzzzz...." when I turned switch to position 1(pre-heat), is this normal?
 

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1985 380SE
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The thermostat housing is made of aluminum and it can strip if you're not careful with it. Since you'll be replacing the thermostat now would be a good time to do a cooling system flush and belts since you'll have things taken apart down there. I like to remove the fan shroud, the fan, and the top rad hose to have some room to move around. You need a 10mm & 13mm socket, ratchet, pliers for the shroud clips, a couple screwdrivers, and a big catch pan since you'll end up spilling coolant no matter how you go about doing the job. When you're done it's a good idea to "burp" the system to get any air out of it. Put the front end up on ramps and run it for a few minutes with the rad cap off.

*If you decide to go ahead with a system flush be sure to turn on the heat so you can flush out the heater core as well.
 

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81 300TDT WAGON , 82 300DT SEDAN, 84 300TDT WAGON(retired),
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442 Posts
Discussion Starter #8
This thermostat: Your Parts Search Returned 1 Part(s) comes with the "O" ring you need.

Not sure on the aux pump. If you have the capability, apply power, briefly, to it, and listen.
The thermostat housing is made of aluminum and it can strip if you're not careful with it. Since you'll be replacing the thermostat now would be a good time to do a cooling system flush and belts since you'll have things taken apart down there. I like to remove the fan shroud, the fan, and the top rad hose to have some room to move around. You need a 10mm & 13mm socket, ratchet, pliers for the shroud clips, a couple screwdrivers, and a big catch pan since you'll end up spilling coolant no matter how you go about doing the job. When you're done it's a good idea to "burp" the system to get any air out of it. Put the front end up on ramps and run it for a few minutes with the rad cap off.

*If you decide to go ahead with a system flush be sure to turn on the heat so you can flush out the heater core as well.
Thank you!
 
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