[Robotech]

Fuses first, then your fan assembly. To check the fan, get the car up to operating temps then let it idle. If it comes up over 200, you should have your fan kick on. If it doesn't, then the fan is not functioning properly.

The other possibility is a frozen or stuck thermostat...but it would seem odd to me it would stick up to 250 and only start flowing again once you started moving.

 

[Yogi]

Check the coolant level first. That is the easiest thing to do. The level should be right at the seam in the middle of the coolant reservoir.

I had a similar problem a few months ago. It was caused by a faulty fan controller (See Post #3 , above). To fix the problem with GM parts costs about $300 because you hafta buy the fan, the motor, the shroud, the controller, everything to do with the fan (at least if it is a Redline anyway). I bought just a Ford controller on E-Bay for $22 and it works just fine.

Yogi

 

[Yogi]

More info about my Ford controller herehttp://www.skyroadster.com/forums/f24/another-succesful-radiator-fan-controller-replacement-76793/

Yogi

 

[IronEagle119]

Yogi, et al,

Thanks for pointing that out. I did actually purchase one of the Crown Vic controllers the first time this happened to me and it did not work. I ended up having to replace the entire shroud fan assembly. I may still have the old fan controller laying around, but for some reason I think it may have been thrown away since my car parts pile up in the laundry room and that drives my GF nuts.

Coolant level is almost flush with the seam, a touch low (1-2 cm). But nothing that I would expect trouble from. Maybe I'm wrong in assuming that level is OK?

I can confirm that at idle the fan is turning on at 199 and turns back off around 190. The sudden rise to 250 is very weird and concerning that this is going to come back at an equally inconvenient time.

 

[IronEagle119]

*Update

The temperatures have been stable since the issue came up last week until today. I've been watching the temperatures more closely and they have been pretty stable between 189-199.

Today on my 3 mile drive home I was at 189. Sitting at a light and checked back and my temps quickly rose to around 230. I did hear the radiator fan running, but it wasn't lowering the temps. I started to move again and the temps held steady at 230. At this point I noticed the heat started to blow ice cold. I was almost home so I was hoping to take it easy the rest of the way as long as the temps were steady. While driving the temps rose to 250, but suddenly & rapidly drop back down to 190 and the HVAC started to blow warm/hot once again.

To me this sounds/feels like a coolant circulation issue. Possible bubbles are forming somehow inline when there previously weren't/shouldn't have been? I corrected this issue during the summer initially, but at no point after the initial replacement of the fan assembly, etc. did any odd issues come up with cooling the engine during the summer months.

Does this also sound like a failing thermostat? Could that be a root cause of bubbles in the air, or would this be more an issue that the t-stat is getting stuck closed and preventing circulation of coolant?

 

[Yogi]

As long as the fan was running wide open when the temp rose to 250*, I'd say that there's a good chance that you have a TStat problem. At least that's where I'd be checking next.

Yogi

 

[Robotech]

I'm with Yogi here, that sounds like a Tstat issue. IF I'm looking at the assembly correctly, when the thermostat is closed water isn't flowing to the heater core (which would make sense because you want the water to heat up to operating temps with the engine before you start taking heat away from it in the heater core). So if temps start rising and your heater stops working, it would seem to make sense that the thermostat has closed, gotten stuck and you have drawn all the heat out of the motionless water in the heater core.

Change out the thermostat (not expensive but not exactly easy either) and see what happens then.

 

[LAC Sky]

Given that the temps, do rise to the 230-250 mark, I would check into a thermostat replacement quickly. Fluid been replaced? Water pump? I had that stuck thermostat issue in the 3000GT, which led to water pump replacement. Better that and the costs, then warping the head or other related issues. With colder weather ( its snowing here right now ) your temps should not be any higher than 210 ( ? ) given heater core usage. Does the fan run with the A/C unit on, and the temps are still high? IF so then you could be ok, but do you want to risk it? High temps are never a good thing, IMO. Yeah our car does run a little warm, that is the nature of the beast as the Kappa goes. IF you don't see a quick cool down from 230, Houston we have a problem here. Fix the system now, in your driveway or at the dealership, and the costs that go with it. Otherwise I would suggest you look at head or motor replacement in your near future.

It might happen. Or you could ride it out, and see what happens, run it till it blows up. Nah not in my book. Battery will start your car, IF it is good enough. Tires will control your car IF they are good enough. Brakes will stop your car if they are good enough. Radiator fluid will cool your car, until it doesn't and your faced with the SM telling you, you head is shot or the block is cracked. Pay now, or pay later up to you how far, and how much your Kappa and the permagrin it brings, is worth to you?

If you can't or won't do it yourself, call the dealer stealer and get a price now, so you will know what it is gonna cost you, when you hit 250 again, and it does not cool down, while towing it to the dealership.

LAC

 

[IronEagle119]

Yogi, Robo, and LAC,

Thanks for all the replies. I got the car home last night and it is just sitting until I get the parts. Back to relying on Uber to get me to work. :frown:

I've started to collect some estimates and am going to compare those to doing the work myself.

King Buick GMC, Gaithersburg MD
(40 minutes to dealership)
Parts:
Thermostat ~$50
TStat gasket $27/each x 2 = $54
Labor: $530
Total: $634

Ourisman Chevrolet, Alexandria VA
(30 minutes to dealership)
I've had some good and some terrible experiences with this dealership. Not sure I'm interested in going back to them, but they are the closest dealership to me.

Georgetown Shell, Wash. DC
(10 minutes, most convenient location)
Parts: $110 (Not sure if the parts are OEM. Will clarify or bring my own parts)
Labor: $320
Total:$430

Doing the work myself:
Parts:
Thermostat 12622410 $37.68
Thermostat gaskets, does anyone have the part number for these? I need 2, correct?
I could possibly try to do this at work in the parking garage. I'm still reviewing the process, but it doesn't seem too terrible. Not easy, but not deadly. However, if I do run into issues it makes things significantly more stressful and I'll wonder why I didn't just spend some money on labor.

 

[Robotech]

The part that makes this hard is where the thermostat is located in relation to the other parts in the engine bay. It's on the back side of the engine on the passenger side. I didn't change mine when I did the turbo so I'm not sure what's the best way to access it.

I'm sure removing the windshield trim that sits over the engine bay will help a ton. So would dropping the cat as it would give you a bit more room back there however with the window trim gone you may be able to come down on top of it okay. I'm sure others here will have more input.

 

[stungjoe]

IMHO if I was to be that far into tearing things down in that area you may want to consider at a water pump replacement. It's my understanding the tube from the back of the water pump goes directly into the T-stat housing. You'll have most everything out of the way. It's just that darn clamping tool to hold the chain in place. If that sucker slips I hear it's a PITA to get to that tensioner. Depends upon the mileage if you would be better off or not.

http://www.kappaperformance.com/forum/index.php/topic,9564.msg158673.html#msg158673

 

[Robotech]

stungjoe has a point but at the same point in time, it's a lot more work, even from there, to get the water pump out. Unless he can do it with everything in place like some have, he would need to drop the exhaust, drop the cat, pull the turbo, possibly pull the manifold and then get out the thermostat housing, water line, and finally the pump. There would be no need to take off the windshield trim if you went this route.

As opposed to removing the windshield trim, possibly dropping the exhaust and cat, removing the heater lines, and then removing the thermostat cover rather than the entire housing.

Getting to the water pump is a FAR bigger chore than the thermostat.

 

[IronEagle119]

I see the point in changing the water pump since they are prone to failure. I too have had one replaced under warranty. But I believe this is a little more scope of work than I'm ready to fit into a workday, at work, in a parking deck.

I've been reviewing posts in how to change it out and doesn't seem too terrible.

Specifically Gordon shamway's post
http://www.skyroadster.com/forums/f5/report-replace-thermostat-41653/

 

[TexSon]

I came across this thread since the 07 I bought came close to overheating on the way home. It got up to 245 sitting in traffic and back down to 225 the next mile home. The fan is not spinning, and I need to test components this weekend. I am hoping the fan will run, but if not will replace the module. The GM Direct diagram shows the shroud, fan blade, motor, etc. as separate components, but only sells it as one unit which sucks. Good to see the Ford module will work and Amazon (https://www.amazon.com/Radiator-Coo...=8-2&keywords=RY1532+Fan+Control+Relay+Module) also has it for $22.99. I am hoping that is it, if not and it is the fan I am going to see if I can make a universal replacement work. $79 vice I think $350 at GMPartsDirect is worth the ole college try...

 

[Sly Bob]

The module is a pretty common failure. Let us know if replacing it fixes the issue.

 

[TexSon]

I got to test it last weekend as I had to take off the intake box and radiator hose to get to the module to test the fan. A bit of a PITA, but the fan is strong so I ordered a new module and will put it in this weekend. GM really f-ed it up when they made it one unit. If I ever do have fan issues, I will take it apart and see if the local parts house has a fan motor to that is close. But $23 vice $350 is definitely a no brainer. As is doing as much of my own work as I can. When the dealer wants almost $200 to change the plugs, something is seriously wrong. Instead of over $4K for parts and repairs, I have so far spent about $800 on parts including the shocks and vapor canister yet to install, which accounts for half the total. I think total time on the other parts, to include the variable timing solenoids, plugs, AC controls, and pulling the fan module is about, and if I really stretch the work, 10 hours. Even at $120/hour that is $1200, which is what the dealer wanted to install the AC control panel along. How the hell do they estimate their hours?

 

[TexSon]

Well, replacing the module didn't do the job, so now I am thinking about putting in a radiator thermostatic switch to kick the fan on. Of course that means taking off the module connection to do so and I am not sure what that will do to the ECM. Has anyone tried that?

 

[Yogi]

Well, replacing the module didn't do the job, so now I am thinking about putting in a radiator thermostatic switch to kick the fan on. Of course that means taking off the module connection to do so and I am not sure what that will do to the ECM. Has anyone tried that?

I am not familiar with the "radiator thermostatic switch" TexSon. Where does it mount? AFAIK, The ECM and the Fan Controller control the air, while the Thermostat controls the coolant flow.

Yogi

 

[TexSon]

Basically with an electric fan you have a few options to control it. The Redline is using the ECM and fan control module, while the 2.4L uses the ECM (actually the temperature from the ECM). Before computers controlled cars with an electrical fan you had two options, a manual switch in the cockpit, or a thermostatic switch (TS). The uses a sending unit, either the temperature sending unit in the block or on that is inserted between the radiator fins. This wire from it goes to a relay, which controls the power to the fan. Thus the fan cuts on when the switch reaches a preset temp, or you can also have a manually set trigger temp.

 

[Yogi]

Basically with an electric fan you have a few options to control it. The Redline is using the ECM and fan control module, while the 2.4L uses the ECM (actually the temperature from the ECM). Before computers controlled cars with an electrical fan you had two options, a manual switch in the cockpit, or a thermostatic switch (TS). The uses a sending unit, either the temperature sending unit in the block or on that is inserted between the radiator fins. This wire from it goes to a relay, which controls the power to the fan. Thus the fan cuts on when the switch reaches a preset temp, or you can also have a manually set trigger temp.

I see. So, your planning on installing a control circuit that the 2.0 LNF does not currently have?

Yogi