No heat at idle now!!!!

[gixxer1kr]

I need some advice. A while back I had no heat and my car took forever to heat up. So I replaced the thermostat and flushed the system and Bled the system. Heat was exceptional. Car got up to operating temp quick and I could cook an egg on the heater. Now I'm having issue with heat . Seems cold at idle then when I rev it to about 2500 rpm it gets hot again. As soon as the rpms drop so does the temp. What is it I remember reading something about this and it pointed to the issue. It's an 02 LS v8 with about 90k that I am beginning to hate lol.Valve covers and sway bar were a bitch now it's the heat again. And got new breaks and calipers on the way. She's a keeper but always something.

 

[joegr]

I'd use brakes instead of breaks, just saying...

Weill, this has probably never come up before, but just for fun, let's check.
https://www.google.ca/search?as_q=N..._occt=any&safe=images&as_filetype=&as_rights=

Oops, I guess it has happened to a couple of other people...

Long story short, you probably need a new degas bottle, thermostat housing (if not recently replaced), top radiator hose, and aux pump. (Okay, it's probably mainly the aux pump, but you need those other things too.)

 

[gixxer1kr]

I was hoping you would reply Joe. I did search the **** out of it but seems like everyone whines and the topics end up all over the place. I am thinking auxiliary pump also. Doesn't seem to have air and don't seem to ever over heat. What's the part # for the auxiliary pump I would have to figure oem is the way to go as is everything on this car. Thanks

 

[joegr]

1w4z-18d473-aa

 

[don-ohio]

On a NORMAL heater,that is classic symptom of a WEAK water pump or low coolant level.Don't know about this auxiliary pump.don-ohio ^)

 

[gixxer1kr]

Car don't overheat Don. Joe is spot on with this issue!!!

 

[RigsLS]

Re&Re - OEM Auxiliary Coolant Flow Pump - GEN 1 V8


1W4Z-18D473-AA - TascaParts.com

:: check RockAuto and/or your local Dealership, ask them politely for a discount.


Like Joe say though, the rest of the plastics that make up the remainder of the cooling system are at a point in time where it's deteriorating and will begin to fail piece by piece. back to back or all at once. This is a well known facts on the LS cooling system. 10yrs + and it's best to redo the entire system. Many of us have done so.
​

 

[RigsLS]

GEN I - Understanding Climate Control System - No Heat Information



​

Auxiliary Coolant Flow Pump

~ The Auxiliary coolant flow pump is electrically driven and provides increased coolant flow during low engine speed operation.
~ The pump is also used to circulate coolant after the engine is turned off under certain conditions. (???)

#4 is the Auxiliary coolant flow pump P/N 18D473 (3.9L only)


Removal and Installation

1. Disconnect the battery ground cable. For additional information, refer to Section 414-01
2. Drain the radiator. For additional information, refer to Section 303-03
3. Disconnect the connector
   View attachment 828453941
4. Remove the two auxiliary coolant pump to fan shroud bolts
   View attachment 828453942
5. Disconnect the hoses and remove the pump
   View attachment 828453943
6. To install, reverse the removal procedure
   • Make sure that the heater hoses are installed in the correct position.
   • Lubricate the coolant hoses with MERPOL® meeting Ford specification ESE-M99B144-B or plain water only, if needed.
   • Check for correct hose installation by verifying DATC system operation.

View attachment 828453945

Port

1 - Inlet from engine
2 - Outlet to coolant valve​

 

[RigsLS]

:: NOTE

~ On the first GEN you can replace the plastic Thermostat housing with the JAGUAR direct fit all aluminum unit.
~ Cheaper, readily available and better overall. Two back bolts need to be shaved down a bit to ease installation

Re&Re - Jag Aluminum Upgraded Thermostat housing - GEN 1 V8


ÜRO PARTS Part # NCE2247ADKIT = Jaguar Aluminum Thermostat housing



​

 

[don-ohio]

Car don't overheat Don. Joe is spot on with this issue!!!

Oh yeah,I'm sure he is. I wasn't questioning the diagnosis,just kinda thinking out loud.
Also,I've seen the weak water pump on other, less complicated cars cause a bad heater at low rpm without causng any overheating of the engine. don-ohio ^)