1984 300td euro. I recently changed out the thermostat because I was overheating. Now the car stays a consistent 100C. Closer to 115C with air conditioning. I burped her. I'm wondering if it could be my temp sensor.

What does it look like? I attached a picture of what I believe it is. This little plug is on top of the glow plugs. Are these things serviceable?

I have an infrared gun. How accurate is it to use it?

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1984 300td euro turbo

Hmm.. I just looked at my engine. I believe I found it. Is this it?

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1984 300td euro turbo

that looks like it could be it, it should have a lead running directly to the cluster. the new part is cheaper than 10 dollars at the dealer. i think theyre the same in all gas/diesel models.

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95 E320 24k
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1977 240d 481k
2013 SL 600


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Do you have instruction for the non contact IR gun? it is very accurate on non shiny surface. Test it with a pan of boiling water to make sure it is correct then point it to the location of the temp sensor or cyl block. If the surface is shiny then tape a 'duct tape' on top and wait for while ( say 5 min ) and redo it again.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

The lead goes to the same line as the glow plug wires.

Starting to boil water now in a black pot and will check temp once boiling.

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1984 300td euro turbo

Is this the temp sensor I would need? Look like my local napa has it.

https://www.napaonline.com/Catalog/CatalogItemDetail.aspx?A=ATM0055421017_0257679580&An=599001+101984+50044+2044077

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1984 300td euro turbo

I think the temp sensor pic you posted is the one for the glow plugs, the temp gauge sensor is elsewhere.

-J

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

I'm sure that has to be it. I pulled it and my gauge rad nothing. Plugged it in and gave a reading.

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1984 300td euro turbo

Fair enough!

On an 84 the glow plug temp sensor is in the relay. Earlier models had it in the block.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

The temp sensor is in the head as you've found out

Here's what it should look like

http://catalog.peachparts.com/ShopByVehicle.epc?q=&yearid=1984%40%401984&makeid=63%40%40MERCEDES+BENZ%40%40X&modelid=6233%3AED|10000135%3AMBC|1518%40%40300TD&keyword=temperature&subcatid=P:240675@@Water%20Temp.%20Sensor&mode=PA

Don't forget to click on buy parts above even if it is to find nice pictures like this!

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

HA yes. I actually did look for it and couldn't find it.

Ok riddle me this smarty pants... What is the difference between what the manual calls "Temperature switch" and the Temperature sender/sensor? Both look quite similar...

Here's a pic of the temperature switch... My car doesn't have this on the thermostat. Wondering if this is the part I need. Maybe I've had it all along!

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1984 300td euro turbo

Temperature switch means it is either Normally Open or Normally Closed. It open or close at temperature. It is like digital devices with 2 states only.

Aux fan, clutch fan are switches.

Temperature sensor is analogue. It is continuous and give you different resistance readings at various temp. The temp gauge sensor is one.

I normally test the gauge this way. Remove wiring then the dash would read nothing. Short the wiring to ground then the dash temp would go thru the roof.

Good luck.

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

Thank you!

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1984 300td euro turbo

'You all set now?

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!