Member Since: 19 Jun 2020
Location: New Mexico
Posts: 5
Overheating with surging fans
Hello, I figured I'd pick everyone's brain here while I'm waiting on my scan gauge tool to get more definitive answers. I have a 2007 LR3 with the V8. It currently has 187k miles on it, and I use it as a daily driver. We just bought a 3600ish pound (1632kg)camper and we took it out for the first time this past weekend. On some of the steeper inclines, I noticed that the the temperature would start climbing after a few minutes, but almost exclusively above 4000 RPM. This was remedied by turning off the AC and turning on the heat( which quickly brought the temperature down). It was on several of these climbs with the AC off that I noticed a pulsing/surging from the fans. It would be a pattern of on for 1or 2 seconds, then off. And this continued until the grade would level out and everything would return to normal. We'd be able to kick the AC back on and continue on our merry way. The ambient temperature was between 75F and 83F. Im currently waiting on a Scangage 2 so I can monitor temps live when I try and re-create it, but does that sound like more of a fan issue or a thermostat issue? It hasn't thrown any codes according to my GAP tool, and it is completely fine in every other driving situation. Obviously my system is getting up there in age, but instead of throwing buckets of money at replacing the whole cooling system at once, I'd like to have a better place to start. I have a new thermostat and housing that I've had just in case, but what does everyone think? Should I just start at the thermostat? Or should I be looking at the fans first?
Thanks!
8th Jul 2024 11:46 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4917
I would think it's likely to be a fan clutch issue which is not difficult to replace. If it's not roaring at you when you notice the temp gauge rise then it's not doing it's job. The fan is PCM monitored so there should be a fault code logged when you scan the modules.
And, scan all modules! yµ (idµ - eAµ) ψ=mψ
9th Jul 2024 2:38 pm
NMSeries
Member Since: 19 Jun 2020
Location: New Mexico
Posts: 5
Thank you. I'll get my GAP plugged in and take a look.
9th Jul 2024 7:03 pm
NMSeries
Member Since: 19 Jun 2020
Location: New Mexico
Posts: 5
Click image to enlarge
Finally able to dig up my GAP and it gave me this code. I'm confused as to why it didn't give me the mileage and more details like it usually does. I cleared it, so we'll see if it comes back. Does anyone know what the "Fan Performance" would be? I've heard of the rationality check malfunctions or the frequency modulation errors, but nothing as generic as this.
Thanks
9th Jul 2024 7:31 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4917
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
