With the return of cold weather I've noticed that my coolant temps have been a bit on the low side. During summer my coolant temps are usually 194 F, and of course sometimes warmer when pushing hard or idling. I was driving the other evening and saw my coolant temp was ranging between 178 and 184. Occasionally I get a P1498 code when it's cold, but I'm not sure if that's related to the thermostat. Should I be concerned that my coolant isn't warm enough in cold weather? it also seems to me like it takes longer than it used to warm up when it's cold, but that could be in my head.

 

If the car takes longer to warm up, and the temperature is low, the thermostat might have failed open

 

that's sure a thought, though it behaves like it closes around 180 degrees F because the coolant temp doesn't ever go below that even when I'm idling coming down mountain passes.

 

Yeah, you should be concerned the coolant temperature isn't getting warm enough, the engine is running too cold -- hence the error code.

Think njaremka's opinion the T-stat is stuck open is a distinct possibility. But it could be just a lazy T-stat.

 

Does that code usually correspond with low coolant temp? I remember when the M7 thermostat was being sold they said it could throw an error code, but I haven't been able to find out what code it throws. everything I find for the P1498 code says unmetered air in the system. Thermostats are cheap and I hate changing them cause I have to pull so many things out of the way to get to it, but it's not hard, so maybe I'll just swap it out and see what happens.

 

P1498 wouldn't have anything to do with the coolant temperature. I would expect a vacuum / pressure leak on the intake manifold somewhere. Perhaps a vacuum hose that broke or popped off?

 

That was what I thought originally, but here's the back story on that code. I got it a month or two ago. I live in Colorado but have to go to KS for work 5 days a month. The car ran fine the whole drive there but once I got to KS the code popped up after I washed the car and stayed active until I was on my way out of town later that week. I cleared the code and it didn't return for the 3 weeks that I was home. Then when I went back to KS the next month, the code returned and kept popping up even when I cleared it. I figured maybe I had a vacuum leak that had gotten worse, but the code cleared on my way out of town and hasn't returned since I've been back.

Both times the weather has changed from warm to cold (60's to 20's) on my way out there. It's such a weird problem that I'm really not sure what's causing it. It is a pre-facelift car with a facelift ECU with a JCW tune with 380cc injectors, and a 17% pulley. I never got this code with cold weather until I swapped ECU's but I'm really not sure how the ECU or tune would cause this code. I tried going back to the stock ECU and tune but the EWS is out of sync with the key so it won't start and I haven't gotten around to learning INPA and disabling it.

It's about a 2,000 foot difference between where I live in CO and where I work in KS, maybe that's just enough oxygen to trigger that code with a small vacuum leak?

 

Odd..
I too have a pre with a post ecu in it...
I get a random p0302 cyl #2 misfire so I went digging..
Whsn I disconnected my catch can i immediately got a p1498 code too and i smoke tested to check fir vacuum leaks and theres NONE. then i put back on my catch can , the p1498 code goes away and never comes back but then randomly i will get the p0302 code again... im positive the car has NO mussfires and NO vacuum leaks.... i believe the problem is with the post ecu in a pre car , something isnt communicating correctly...
Im running the factory GP tune in my ecu also , is your custom tuned or jcw tune ???
I think I'm gonna yank out the post ecu and try my pre and see if it has anything to do with the new ecu and or tune in that ecu , because thats all im left with checking.
I put new gaskets through out engine , new vacuum hoses too , sensors, tune up ectectect and NOTHING Is preventing the codes from coming back , either I run my catch can amd get an occasional p0302 or I renive it and have a consistent p1498 WITH eml light too sometimes...
I will lyk if swapping back to the old ecu helps but I need to get my injectors here 1st...

 

Super odd, I don't have a catch can on my car at the moment, but I consistently get that code with a CEL when I go to Kansas, and often get an EML light as well. I've had the EML light come on a couple of times in other places, but it always self clears if I turn the car off and back on. I have the factory JCW tune on my post facelift ECU, with 380cc injectors, alta CAI, 17% pulley, and stock intercooler. My car runs just fine and while I haven't checked it for vacuum leaks, it doesn't have any signs of a vacuum leak. I tried to put my unmodified factory ECU back in, but the keys are out of sync with the EWS and I don't have a computer that can run INPA, so I've been trying to find other options that don't involve paying $200 to have someone else do it.

I too suspect that theres some sort of issue in the ECU or with the 2 communicating, but you're the first person I've heard of that also has this issue.

 

my car doesn't have cruise from factory but I just found by lookinglookmy facelift ecu configuration and it says that the cruise is activated and on bit I get errors from lack of communication then between the 2x systems. Only inpa and icarsoft have been able to see those body codes buuuuuuuut I wonder , I WONDER if the ecu wasn't correctly setup to have cruise switched off and I wonder if that some how playing into this odd cel.. I also checked fuel trims and they were PERFECT. I watched 02 readings , fuel injectors pulse, knock , cyl roughness and EVERYTHING was PERFECT and I mean perfect. Fuel trims were spot on .
I also sealed EVERY tiny exhaust leak I had too even though they were well past the 2nd 02 sensor but yet infront of the mufflers..
after exhaust fix , adjusted the o2 spacers exactly how it is in my other car and the cel stayed off longer than it has yet BUUUUUUT as soon as I let the car idle for 5min about with no throttle input or anything ( like if I'm warming it up ) then the code pops up . Odd , that seems to be the only time the code comes on..
IF I don't end up trading my car tonight , I will toss in the old pre facelift ecu with factory S tuning and see if that has any changes as far as cel goes..