Hello I have a 214 c300 merc benz.
It seems to be heating up the temp jump between 100 and 120 c.
The heater seems to work sometimes when the car is at low temp.
When it starts acting up the fan kicks into high speed and stays on and the heater doesn't always work.
When it gets hot there is alot of pressure in the top radiator hose. When it's cooler there doesn't seem to be much pressure in the hose.
And when u hold tge hose tight u really can't feel water gushing thru the hose.
The temp seems to jump around between 100 and 120 c but like I said the fan stays on n it seems to cool off.

What would be a good starting point for a repair?
New thermostat n housing ?

Sure

What is the mileage?

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Jim

34000 miles .
No code or check engine lights r on

It is a 2014

Hi Jim, I replaced the thermostat. The problem actually seemed to get worse. The temp went between 100 and 130 the working light came on the car was overheating to shut it off. The heater was blowing cold. Any suggestins?

It is easy on many models to install t stat backwards. Are you sure you got it in the correct way?

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Make sure you got all the air out of it. Run it, get it up to temp and then shut it down and check/fill after it has cooled down.

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Jim

The thermostate was a housing/thermostat so yes it can only go on one way.
I'll check the levels again when I get home hopefully it's just low on coolant now

Hi Jim anti freeze was low added some and drove it it still acted up doing same thing I let it cool off and checked anti freeze it was full.
Do u think I should drain anti freeze n try to flush it?

Does temp go up while driving down hwy or sitting at a light. What are the ambient conditions?

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Jim

You pretty much figured out the problem or the most likely problem when you created this post. "The heater doesn't always work.
When it gets hot there is alot of pressure in the top radiator hose. When it's cooler there doesn't seem to be much pressure in the hose.
And when u hold tge hose tight u really can't feel water gushing thru the hose."
1.Heater doesn't work because there isn't any flow of coolant.
2.There is no pressure when cooler because engine isn't at temp.
3.There is a lot of built up pressure when hot in top hose because the temp, chances are the lower radiator hose isn't hot at all.
4. You can't feel the water flowing through the hose because the pump either isn't working or you have a major blockage.

Why don't you either test the water pump or take it to a mechanic. An overheating engine isn't something you want to mess around with if you aren't really sure of what's going on. A $200 -$400 cooling problem can quickly become a several thousand dollar head gasket job or complete engine rebuild.

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1990 190E 3.0L