Emmet505
New member
Hi All,
Apologies if this is in the wrong section and / or I’m not following normal forum etiquette; this is my first post!
Just wondering has anyone ever had an issue with a Volvo Penta md2020 B not getting up to temperature? This is the first time I’ve had this issue. For clarity I’m attaching a diagram that shows the assembly of the thermostat, located inside the heat exchanger tank.
I took the heat exchanger tank off to re spray my engine and since I put it back in, with a new thermostat that I verified was working, it is not achieving normal operating temperature. The first tell tale sign of trouble is that heat exchanger tank gradually gets warm, rather than staying fairly cold until the thermostat opens. The maximum temperature I’m seeing on the gauge that I retrofitted is about 70 degrees, after plenty enough time for the engine to heat up. I even tried bringing the boat out of the marina to put the engine under a little bit of load.
I believe the issue is to do with the thermostat not seating tightly enough against the flange inside its housing, causing coolant to pass around it and prematurely enter the heat exchanger. I took the heat exchanger off a second time and tried reseating the thermostat against the flange. Initially my fix seemed to work with the engine achieving approx 87 degrees. Additionally as I let the engine heat up, the heat exchanger warmed up in the more normal fashion, of staying fairly cold until the temp on the gauge reached about 75, at which point the thermostat would have started to open. That initial successful test was conducted last night. Unfortunately when I tried to repeat the test this morning, it reverted back to slowly climbing up as far as 70 over the course of 20 minutes and the heat exchanger tank gradually getting warm.
My next course of action would be to take the heat exchanger off again and try and sparing use a liquid gasket compound to run a bead along the corner of the flange where the thermostat seats, that would hopefully make the thermostat seal a bit tighter. Would anyone have any insight into whether this could solve my problem or would it cause other issues? Better again, would anyone have any other suggestions as to what the issue could be, in case I’m just chasing a dead end with my current theory?!
Any advice would be much appreciated.
![IMG_6950.jpeg IMG_6950.jpeg](https://ybw-data.community.forum/attachments/131/131604-a2cd7221e85651fc547e3f3a50269e34.jpg)
Apologies if this is in the wrong section and / or I’m not following normal forum etiquette; this is my first post!
Just wondering has anyone ever had an issue with a Volvo Penta md2020 B not getting up to temperature? This is the first time I’ve had this issue. For clarity I’m attaching a diagram that shows the assembly of the thermostat, located inside the heat exchanger tank.
I took the heat exchanger tank off to re spray my engine and since I put it back in, with a new thermostat that I verified was working, it is not achieving normal operating temperature. The first tell tale sign of trouble is that heat exchanger tank gradually gets warm, rather than staying fairly cold until the thermostat opens. The maximum temperature I’m seeing on the gauge that I retrofitted is about 70 degrees, after plenty enough time for the engine to heat up. I even tried bringing the boat out of the marina to put the engine under a little bit of load.
I believe the issue is to do with the thermostat not seating tightly enough against the flange inside its housing, causing coolant to pass around it and prematurely enter the heat exchanger. I took the heat exchanger off a second time and tried reseating the thermostat against the flange. Initially my fix seemed to work with the engine achieving approx 87 degrees. Additionally as I let the engine heat up, the heat exchanger warmed up in the more normal fashion, of staying fairly cold until the temp on the gauge reached about 75, at which point the thermostat would have started to open. That initial successful test was conducted last night. Unfortunately when I tried to repeat the test this morning, it reverted back to slowly climbing up as far as 70 over the course of 20 minutes and the heat exchanger tank gradually getting warm.
My next course of action would be to take the heat exchanger off again and try and sparing use a liquid gasket compound to run a bead along the corner of the flange where the thermostat seats, that would hopefully make the thermostat seal a bit tighter. Would anyone have any insight into whether this could solve my problem or would it cause other issues? Better again, would anyone have any other suggestions as to what the issue could be, in case I’m just chasing a dead end with my current theory?!
Any advice would be much appreciated.
![IMG_6950.jpeg IMG_6950.jpeg](https://ybw-data.community.forum/attachments/131/131604-a2cd7221e85651fc547e3f3a50269e34.jpg)