Not certain if this is a new feature but after driving around today with several stops and upon returning home and after shutting the car off, I noted the engine cooling fan was still running. In eight years it has never done this and in fact I can't remember the last time any car I have owned in the last 15 or more years has ever had the fan run after turning the car off. I waited several minutes and still it did not turn off so I turned the car on and then off and the fan turned off as well.

Glitch or is this a new feature?

 

It might not be a bad idea to check the temperature with an OBDII reader when you next go out for a drive.

My suspicion is that you are suddenly running hotter than normal....perhaps a sticking thermostat.

 

Most/all of my vehicles do this, you just happened to catch it on a cooling cycle. The fan's thermostat had just detected enough heat to turn on the fan, so it turned on and then you shut the car off. Fan wanted to run a bit longer so it did. Completely normal.

 

Agreed, or if you don't have a reader handy but have an IR thermometer you can check temps in various spots, including in front of and behind the thermostat prior to disassembly.

 

Glad to hear your fan continues to run, the same as mine.... when it's necessary.

 

Check your thermostat and your water pump (immediately) unless it was very warm outside and you were in heavy traffic. The fans kick on and stay on for a reason, and that's to get rid of excessive heat. They are the first warning.

 

I assume that since you are posting this that it's unusual so I would look further into it via IR gun or scan tool for temp readings. Things are only normal until they aren't.

 

Yes it has NEVER EVER done this before. I'll keep my ODB dongle handy and monitor temps just in case.

 

It's a 2008 4.2 XKR with relatively low mileage, no heavy traffic but yesterday was fairly hot low 90s, I had been driving for less than 1 hour but had run out of methanol. Maybe it is time for a killer chiller...

 

It is just bizarre that it has NEVER done this before, ever.

 

Did you check the coolant over flow tank etc?

 

Dirty cooling system?

 

You still have the tune from me in the car, right?

One of the modifications in the tune is that the fan starts at lower temperatures, and spins a bit faster than standard. Helps to cool down the intercooler circuit, to limit heak-soak when you are parked up or sitting there idling.

 

I did think of that but was not certain if that would apply with the car turned off, plus it has never done that with your tune. Cooling system looks okay, the only other thing I can think of is it was hotter than usual yesterday as cooler weather has finally given up here but it's not like I have ever driven in hot weather or summer. It also did not do it at any other point during the day after stopping.

 

I have the same tune and have had the fans come on after shutdown but only once after a particularly spirited drive. I had not had that happen in the 4 previous years, pre tune, so it may be your new normal now. I would certainly keep an eye on it though!

 

It's nothing to be concerned about really.

The standard operation is that the fans can run after shutdown, if the engine coolant temperature and ambient temperature are above a certain threshold.

With our tune that threshold has been lowered a little bit.

Might be that you haven't had hot enough days before for the fan to run. Hot summer days in Australia >40°C the fan in my XJR would run for a little while after shutdown, same in the Land Rover. Also if you shutdown the engine and turn the ignition back on, the fan will run. That's pretty normal for hot conditions.

 

Did it again today, only once and this time I did not power cycle and let the fan run and it indeed turned itself off after about 5 minutes. I have been monitoring ECT over the past week and have never seen it above 210F, typically it sits around a peak of 208F. I suspect all is well and that it is either due to increased ambient temps or Cambo's tune.

 

Blame Cambo. It's more fun than blaming the weather. Kidding aside, was it hot again today where you live?

 

About 89f, not as hot as it has been or is going to be. It's about 98f now. I'm going to go with Cambo's fan mod. More importantly, my original concern has been relieved which is the fan is working and not coming on for no reason.

 

Jahummer I thought you were running Velocity tune, when did you get Cambos tune?