| Author | Message | ||
     Jdugger |
My bike has been in the shop since early November with a Thermostat problem that's been diagnosed to the ECM. It's still under warranty. Apparently, HD is back ordered until 11/30 on this part, so I'm wondering where else I might be able to source one. Bone stock, OEM, ECM.... I can get a part number if you need it. Thanks | ||
| Strongbad |
Out of curiosity, do you have any more information on the problem and diagnosis? | ||
| Jdugger |
I can tell you the symptoms. The bike will run fine, and then suddenly the bike will think it's cold, and the instrument cluster will flash COLD. This is enormously dangerous, because the bike will rev limit at about 7k unexpectedly, even when pitched over at WOT in a corner! The bike will then intermittently recover. All of the sudden the temp will show 150, 160, 190, 220, etc. Then the fans and water pump come on. Sometimes the bike will be fine for a few minutes. Mostly, it will then just bounce between "COLD" and an erratic read of coolant temperature. It does seem to be worse when really banging on the bike at higher RPMs, but I can't confirm that. It's just a feeling. The black tire covers in soot from running rich. I've taken the bike in and had the thermostat replaced, and that fixed the problem for a couple of track days. Now it's back, and this time the dealer diagnosed the issue to the ECM. They also discovered cracks in the stock muffler, so that's being replaced as well. | ||
| Froggy |
Yes there is someone with a 08 Uly that is also waiting till the end of the month for an ECM. All 08+ Buell's use the same ECM, just different programming on it. | ||
| Tpoppa |
Could that be a bad temp sensor? | ||
| Strongbad |
The reason I ask, is the issues you described typically occur with a cooling system that has an air pocket near the temperature sensor, or a bad temp sensor. I wouldn't expect a bad thermostat to cause the problems you are having, since it is mechanical and the typical failure modes are stuck open or stuck closed. Even if it suddenly went from fully closed to fully open, I have never seen the temperature drop as dramatically as you described. Just some ideas, but I have a feeling that the ECM isn't the root of your problem. | ||
| 1_mike |
And the water pump is "always" working...! Mike | ||
| Jdugger |
I don't believe it's the core issue, either, but the bike is under warranty and I have to go through the process. I guess I don't understand what the difference between the thermostat and the temp sensor is... The issue is definitely with what the bike thinks the temp of the coolant is, because when it reads correctly the bike is fine. I know for a fact the water pump is not always on. You can see that behavior just by following the service procedure for bleeding the coolant. | ||
| Zac4mac |
Jim, the thermostat is a bi-metal mechanical valve. When closed, the coolant circulates in the engine-pump circuit only. When it opens at ~162 degrees, it lets coolant to the radiators. It becomes fully open and "locks" at around 180 degrees. The CT sensor is a "digital thermometer" that tells the ECM what the CT is. Zack | ||
| Jdugger |
Man, I would have never have guessed a thermostat was NOT the temp sensor. Stupid me  | ||
| Strongbad |
Zac is correct with regard to the CT Sensor vs. Thermostat. Also, the water pump is mechanical and is driven by the engine. The pump is always spinning, but the speed is in relation to engine speed. |
