FiveStarSAMz
New Member
Hello guys! I have a mind-boggling issue with my Mercedes Vito Minibus W447 2018.
So randomly I have been having the temperature fluctuation on the temperature gauge. I went on a long 15-hour drive this weekend and here’s what I found.
Temperature dropping: When going at a constant speed at 70mph or constant rpm, the temp gauge will stay at the usual 90deg. But when I try to put the heater on, it blows out cold air. As soon as I lift my foot off the throttle for a little while, or put it in neutral for downhill roads, the heater will become hot again, and the temp gauge will drop to just above 40deg and will keep fluctuating between 40-80 deg for like a minute or so. It'll be a quick fluctuation before staying around 80 degrees and then eventually 90 degrees when I’m driving normal again. The heater will still be hot for a little while (about 15 minutes, enough to keep me warm again.)
Temperature increasing: Again when going at a constant motorway speed (50-70mph), the temp gauge will be normal at 90deg, but as soon as I put a bit of power for let’s say when I want to overtake or I am going up a hill, the temp gauge will increase above 90 deg. I would hear the fan kick in. Depending on how much power I give or how steep the hill is and how long I give the power, will determine if it will go up to 120 degrees or more. But it’ll come down pretty quickly when I ease off the throttle.
When the temperature was up above 120deg on the motorway, I lost all feedback to the throttle, whatever I was doing to the throttle, nothing happened to the van, and I was slowing down. So I had to pull over on the hard shoulder for a few seconds and it was only when the temperature went towards 90deg, I regained throttle control.
So far, I got one thermostat changed but it did not make any difference.
I have a xentry and nothing really comes up as error codes. I’m not a mechanic so I don’t know what to look out for. Any help would be much appreciated.
So randomly I have been having the temperature fluctuation on the temperature gauge. I went on a long 15-hour drive this weekend and here’s what I found.
Temperature dropping: When going at a constant speed at 70mph or constant rpm, the temp gauge will stay at the usual 90deg. But when I try to put the heater on, it blows out cold air. As soon as I lift my foot off the throttle for a little while, or put it in neutral for downhill roads, the heater will become hot again, and the temp gauge will drop to just above 40deg and will keep fluctuating between 40-80 deg for like a minute or so. It'll be a quick fluctuation before staying around 80 degrees and then eventually 90 degrees when I’m driving normal again. The heater will still be hot for a little while (about 15 minutes, enough to keep me warm again.)
Temperature increasing: Again when going at a constant motorway speed (50-70mph), the temp gauge will be normal at 90deg, but as soon as I put a bit of power for let’s say when I want to overtake or I am going up a hill, the temp gauge will increase above 90 deg. I would hear the fan kick in. Depending on how much power I give or how steep the hill is and how long I give the power, will determine if it will go up to 120 degrees or more. But it’ll come down pretty quickly when I ease off the throttle.
When the temperature was up above 120deg on the motorway, I lost all feedback to the throttle, whatever I was doing to the throttle, nothing happened to the van, and I was slowing down. So I had to pull over on the hard shoulder for a few seconds and it was only when the temperature went towards 90deg, I regained throttle control.
So far, I got one thermostat changed but it did not make any difference.
I have a xentry and nothing really comes up as error codes. I’m not a mechanic so I don’t know what to look out for. Any help would be much appreciated.
