[abush1984]

Hey all,

The other day my wife's car had a service coolant malfunction pop up and now the car sounds like it is preparing for take off? I was wondering is the sensor for the coolant good enough to know when the cars antifreeze is going bad? also the car has around 90,000 miles on it and is an 2004 c230 any info would be greatly appreciated.



Andrew

 

[schumicat]

the sensor just measures the level not the quality. the service booklet should say the recommended change but IIRC it is very long (like 10 years or 100k miles), it may even say lifetime fill (but I'd change it after 10 years).

 

[abush1984]

so its safe to say that I just need to change the coolant out and all should be good to go.

 

[300DFan]

so its safe to say that I just need to change the coolant out and all should be good to go.

No, I wouldn't assume that at all. It sounds like you have a cooling system issue, and I would be extremely surprised if just changing the coolant would address it. While changing the coolant according to the schedule is a good maintenance old coolant still cools the engine.

You could have a leak and the coolant is low, or a number of different things could be causing the engine to overheat. How hot did the engine get while the fan was running like a turbine?

 

[abush1984]

the car never overheated as soon ass the light came on I had here check the temp at least the temp that shows up on the cluster, and that said the car was running at about 80 degrees Celsius which is normal. the malfunction says "coolant visit workshop" and there are no visible leaks and the system is full so that is what made me think it was just a low alkalinity issue.

 

[abush1984]

also I think the fan maybe unbalanced cause one of the fins has weights on it and it looks like a weight may have come off.

 

[300DFan]

Interesting that the temperature in the cluster read normal while the fan went on full. Was that a one time occurance or does it still happen?

Either way I'd say it's time to get the car diagnosed with SDS. There's definitely something wrong with the cooling system and I don't believe just changing the coolant will address it.

 

[vr2whf]

How often you guys need to top up the coolant?

 

[Noobie23]

I been getting this malfunction check coolant level it happens once a week anyone know? Sometimes when i start the car I I don't get it? Do i need to put some more anti freeze in?

 

[schumicat]

if the level is good the sensor is bad. also on my car if the washer fluid is low it sometimes also erroneously says coolant is low, and filling washer reservoir makes both messages go away. so check that.

to the OP, at most you should have to add a small amount of coolant (pint or two) every couple of years. if you are losing coolant you have a leak or some other issue. check coolant for oil and vice versa (head gasket). better yet get oil analyzed or get a compression check.

I been getting this malfunction check coolant level it happens once a week anyone know? Sometimes when i start the car I I don't get it? Do i need to put some more anti freeze in?

 

[vr2whf]

You refer to cylinder compression test or coolant compression test?

if the level is good the sensor is bad. also on my car if the washer fluid is low it sometimes also erroneously says coolant is low, and filling washer reservoir makes both messages go away. so check that.

to the OP, at most you should have to add a small amount of coolant (pint or two) every couple of years. if you are losing coolant you have a leak or some other issue. check coolant for oil and vice versa (head gasket). better yet get oil analyzed or get a compression check.

 

[300DFan]

If you're losing fluid I'd start with a cooling system pressure test.

It's possible a head gasket problem could also cause fuel loss and show up in a cylinder compression test but that is extremely rare in an M112 engine. Even still, that type of leak may not show up in a compression test. There's a chemical test you can use to detect combustion gases in the coolant which I would use next, if you can't find a leak with a cooling system pressure test.

 

[Noobie23]

if the level is good the sensor is bad. also on my car if the washer fluid is low it sometimes also erroneously says coolant is low, and filling washer reservoir makes both messages go away. so check that.

to the OP, at most you should have to add a small amount of coolant (pint or two) every couple of years. if you are losing coolant you have a leak or some other issue. check coolant for oil and vice versa (head gasket). better yet get oil analyzed or get a compression check.

Yeah a couple days after i added windshield washer fluid i got the message of the check coolant level so i gotta see if I filled it up to top which caused the sensor to go off. I guess there is only 1 message for coolant level and windshield washer fluid. thanks

 

[rudeney]

The washer fluid and the coolant sensors are wired in series so they share a circuit. I believe the way it works is that if both are in proper range, the circuit gives feedback of "0". If the coolant is low, it gives a feedback of "1". When the washer is low, it gives a feedback value of "2". And if booth are low, they are added for a "3". So, if one goes bad, it can cause the other to give a false reading. The washer pump is also on this circuit. When my pump failed and I removed it to bench test it, and then left it of until I got a new one later that week. With it disconnected, I got both a coolant warning and low washer fluid warning until I put the new pump in place.