[Willie]

Hey yall, my speedo, and temp gauge go haywire occasionally. what is happening, and how do i fix it? The speedo will just go to zero, and then come back after awhile. the temp gauge will rise all the way up, and then come back into range. I know that the car is not heating up.

 

[bigdad]

the speedo misbehavior is from a defective VSS (vehicle speed sensor) which is a common failure for Legends. The temp gauge going high and then low is not related to this, but is likely caused by air in your cooling system....usually as a result of hair line cracks in the plastic upper tank of the radiator. The sensor is alternately exposed to air then coolant and thus the bad readout on the temp gauge. However, if you have air in your system it got there because there is a system failure which needs to be detected and repaired before you cook your engine and warp the heads...many have done so on this site. So look around the upper tank, especially at mounting flanges, attachment points and the throttle cable holder...these are common points for stress fractures....you will also need to bleed out the air from the system from the bleeder screw (follow the top radiator hose to the engine and you will find it). Run engine AND heater until hot and bleed out through the 12mm bolt with the hole....do several times to get air out until steady stream of coolant comes out. Careful not to spray yourself and get burned.

 

[Willie]

Thanks bigdad...

I will check that out. I have noticed a slight smell of coolant during long drives, and the reclaimer bottle seems to overflow sometimes, although there is always plenty of coolant in the system. I have had to replace water in the bottle, but never in the radiator.

 

[bigdad]

You definitely have a leak somewhere...the overflow bottle reservoir level should go up when the car is hot, but when cooling down, the system should pull a vacuum and suck the coolant back into the radiator. If you have a very small hairline crack, it pulls in air and breaks the vacuum and you wind up with air in your system and a full reservoir bottle. If you don't fix this, you will wind up with a very expensive repair to the engine. 99%d of the time it's the radiator (happened to me and my son's Legend too...they do this at about 80-100K miles)

 

[Willie]

Makes sense now...

I tried bleeding the air off like you suggested, and never quite got a good stream out of the bleeder. I will go and get the radiator evluated. Are aluminum replacements available??

 

[Willie]

Ended up being the water pump....and since that told me that the timing belt had certainly not been done, I had that handled as well.