I've got a blue2L 1990 carburrettor 190, which went to an independent garage which I've used for years,to have a coolant leak fixed. Now the heater output is a lot lower than before. However, I don't know whether the car is operating more correctly than before or not. I just know that the heater doesn't have the same fantastic (hot!)output that it did before. Now, on max,it's just fairly warm on an average day and decidedly tepid and ineffectiveon a cold day. Previously,it was hot enough to beuncomfortable to keepmy hand in front of the vent, whichwas excellent for those cold British winters.


Car went in the first time and they replaced the radiator and a pipe. They recommended the thermostat be changed too, so I said yes. This is when the problem started.

Before repair, the temperature gauge previously would always stabilise well above the 80c mark, usually around the90c markwhile driving. The heater was hot and the car's performance felt more lively when fully warmed up. The Haynes manual states that the thermostat begins opening at 87c and is fully open at about 100c, so is consistent with this. The standard issuehandbook imparts no useful information, as one would expect...

Now, the temperaturegauge is always at 80c or a bit lower, the heater output is much lower and the car's performance seems more sedate, althoughtypicallyMercedessmooth.

I then had a ride in a 1990200TE andsaw that the temperature gauge in that was also under 80c when fully warmed up, so I now wonder ifmy car was simply running too hot before. Please note that ifmy car is left idling, the temperature gauge will eventually go some wayabove the 90c mark and the fan cut in, which seems correct. In this temperaturerange, the heater output is of course excellent again, so I know that the gauge and temperature sensor are showing a proper reading.

Anyway, the coolant leak had not been fixed. I replaced the radiator cap after realising that it was leaking - which the garage should have spotted in the first place. It was ok for a couple of days,but thenthe leak returned with a vengeance.

Booked it into the garage again, alsopointing out the low temperatureproblem.They replaced the water pump, which finally nailed the leak. Unfortunately, because they were running lateandI needed the car back in a hurry, I discussed it with the mechanic, butIdidn't push for the thermostat to be checked that it's the correct type, so I still have this pesky tepid heat problem.

So, in summary, heat outputis not that greatany more and I'm not quite sureif the car is operating correctly.As you can imagine,I'm finding this situation frustrating andwould reallyappreciate some advice on this.

 

An engine or indeed any device, either mechanical or electronic, is either operating correctly or not. However there is normally a parameter range over which a device is regarded as operating correctly: e.g. the temperature of an engine may be given as 100 degrees Celcius, a study of the manufacturers specification may well give a range of +/- a few degrees. Everything - even thee and me has a tolerance.

Grief and misery come when the spark plugs are worn out a bit, the fuel system is a bit out, the brakes bind slightly, the battery has reduced capacity, the charging system is not quite maintaining the right voltage range, the cooling system is not able to work as it should, and the driver/owner thinks maintenance is for nerds. The result is as Charles Dickens Mr micawber had it; is...... "misery".

The result of having the car set up 'correctly' is generally smooth comfortable travel, and much happiness.