Hey guys I'm having a problem with my CL's coolant boiling after I turn off the car. If it is running the fans are on and it does not boil but when I shut the car off the fans go off and the coolant starts to boil into the overflow. Just to fill in some background I did a manual swap on this car and it sat for almost a year before that due to the auto tranny going out. After I completed the swap and got it running again it ran fine for a few hundred miles and started doing this. My question is why are the fans not staying on? Also could it be the radiator cap or head gasket? if so how can I diagnose these issues. Thanks guys; I just wanted to get some input before I start messing with it.

 

you may want to check your thermostat and see if its stuck. It sitting so long can cause these to stick and cause this to happen. That would be the first thing I checked anyway

 

Also, your radiator cap may be worn out. The spring could be weak and letting coolant by. Instead of just replacing it you should test it so you know for sure. Parts store should be able to do this.

 

Thanks for the replies. I'm going to check the radiator cap for sure because i would assume if the pressure is released that would allow it to boil. On a side note do your guys fans stay on for a few minutes after the car is off? it seems like mine did before the swap but does not now.

 

P0401, thank you I will also check the thermostat and do a flush again; it's just weird that the temp gauge is showing normal temp.

 

if it didn't have this problem before then it shouldn't be a head gasket or anything so the thermostat sticking is probably the culprit. Mine was kind of stuck in the open position so mine wouldn't get warm enough, if its stuck in the closed position it will cause the problem you are having. It could be opening just not enough also but I will almost bet that its what is causing the problem since it never ran hot before you had transmission problems. The radiator cap could do it also but I would check both. As far as fan goes, mine turns off with the switch just like you are describing yours does

 

P0401, thank you I will pick one up on my way home since they are cheap and replace it. That's good about the fans too maybe I'm thinking of one my other cars I had where the fams stayed on. I'll let you guys know what happens

 

yeah my nissan truck the fan stays on for a few minutes after you turn the engine off but I have noticed the acura doesn't do this. if I turn the ignition switch back to the number 2 position the fan will come back on but if its in the off position they turn off just as you described yours doing