Not warming up...

[CERF04ZHP]

Tis the season of warming up your car...

So lately, I've been going outside maybe 10-20 min. before I leave work to start my car and let it warm up. I turn on the heated seat, set the heat at 90 and fan speed 75%.

But when I go to jump in my car to go home, the seat is nice and warm, but the cabin is just as cold as when I started the car 20 minutes prior. Temp. gauge is right in the middle where it should be.

It's not until I start driving down the road does the HVAC start putting out warm air.

What's the problem here folks? Thermostat?

Thanks guys!

[danewilson77]

Maybe HWV?

[kayger12]

Hmmm. Coolant level checked recently?

Does it put out hot air, or is it only getting warm?

[edlvrt]

It is likely that your engine is not really heating up all the way while sitting and idling, and running the heater is acting like a 2nd radiator and in fact lowering the temp of your engine. The best thing to do for our cars is to start them up, put your seat belt on, and drive away without waiting for the car to warm up. It will reach operating temperature much faster than sitting at idle, and will be warm enough to start heating the cabin within a minute or two. Just keep the RPMs under 3k until everything is warmed up. Letting it sit and idle puts a little bit more stress on the engine and the emission system and wastes gas.

[CERF04ZHP]

Cooland level is ok, and the pH is correct also.

Once I start driving, it's hot as it should be.

It's only when I start it and it idles... I can let it run for a half hour, and I get no hot air until I drive.

Dane - HWV? Sorry, I must have my acronymblock up this morning... :-(

[kayger12]

It is likely that your engine is not really heating up all the way while sitting and idling, and running the heater is acting like a 2nd radiator and in fact lowering the temp of your engine. The best thing to do for our cars is to start them up, put your seat belt on, and drive away without waiting for the car to warm up. It will reach operating temperature much faster than sitting at idle, and will be warm enough to start heating the cabin within a minute or two. Just keep the RPMs under 3k until everything is warmed up. Letting it sit and idle puts a little bit more stress on the engine and the emission system and wastes gas.

In light of your levels being ok and it getting hot once you start driving, this is making a whole lot of sense to me.

[CERF04ZHP]

It is likely that your engine is not really heating up all the way while sitting and idling, and running the heater is acting like a 2nd radiator and in fact lowering the temp of your engine. The best thing to do for our cars is to start them up, put your seat belt on, and drive away without waiting for the car to warm up. It will reach operating temperature much faster than sitting at idle, and will be warm enough to start heating the cabin within a minute or two. Just keep the RPMs under 3k until everything is warmed up. Letting it sit and idle puts a little bit more stress on the engine and the emission system and wastes gas.

I can remember a time when I could start my car in the dead of winter, and let it idle for 10 minutes and have HOT air. So something has changed, something's different... I guess that's what's bothering me... it's not so much that I don't have hot air blowing in my face (I hate that anyway), I just want to make sure everything is correct and in proper working order.

[Johnmadd]

Still original cooling system?

[Sockethead]

You need to replace your thermostat. It electric. When it starts dying it stays open. I just replaced two of these with the excact same symptoms and they both heat up normally now....

[danewilson77]

My two thoughts are:

1. Could be failed HWV (Hot Water Valve)

http://forum.e46fanatics.com/showthread.php?t=617301

2. The "Normal" temp band for our cars....indicated by the 1200 position on our temp gages, has a really large band....so, as mentioned, maybe the T-Stat has failed.

[CERF04ZHP]

Still original cooling system?

Water pump/expansion tank were replaced @ 85k - has 125k on now.

Thanks for the help guys. Looks like a T-Stat is in order. Is it too early to do another cooling system overhaul?

[Sockethead]

Water pump/expansion tank were replaced @ 85k - has 125k on now.

Thanks for the help guys. Looks like a T-Stat is in order. Is it too early to do another cooling system overhaul?
I would just do t-stat....

[kayger12]

At 125k I'd be replacing everything if it's original, including radiator and fan switch.

[edlvrt]

If it wasn't doing this before, try to bleed the system again with the car parked uphill. I had a similar thing happen with my E36 where when I came to a stop at a light, the heater would start blowing cool air, then warm up once I drove away. After bleeding, it was hot at all times. There must have been a bubble in the system, and at low engine speeds (idle) the water pump was turning too slow to circulate enough coolant to keep the heater core/me happy and warm. Good luck!

[Johnmadd]

If it wasn't doing this before, try to bleed the system again with the car parked uphill. I had a similar thing happen with my E36 where when I came to a stop at a light, the heater would start blowing cool air, then warm up once I drove away. After bleeding, it was hot at all times. There must have been a bubble in the system, and at low engine speeds (idle) the water pump was turning too slow to circulate enough coolant to keep the heater core/me happy and warm. Good luck!

This^
It sounds like a flow issue. Bleed the system. If that does help maybe a flush would help. If that doesn't help I would look into the radiator if it hasn't been replaced.

[zj96sc]

I concur with the bleeding, if not that then the t-stat....and please stop letting your car idle for 20 minutes off a cold start. This is horrible for the engine.

[CERF04ZHP]

I concur with the bleeding, if not that then the t-stat....and please stop letting your car idle for 20 minutes off a cold start. This is horrible for the engine.

Really? Better to just fire it up and drive away? Any warm-up time at all?

[Sockethead]

Really? Better to just fire it up and drive away? Any warm-up time at all?

Yes, modern cars don't require a warm up period... just don't rev it to the moon while cold :)

[zj96sc]

^this.

I would say no warmup whatsoever is better than a 20 minute idle. We went through this not too long ago (don't remember the thread, maybe a remote start thread?) but basically since there is almost no load at idle the engine doesn't warm up right anyway.

Make sure you're using oil weighted properly for your op temp range, make sure you have good oil pressure on startup, and head on your way. You can help out by keeping the RPM low until all the parts get cozy with each other again....this is usually what I try to do on my ZHP and 7.3L....wait for needle movement and then drive as normal.

[CERF04ZHP]

^this.

I would say no warmup whatsoever is better than a 20 minute idle. We went through this not too long ago (don't remember the thread, maybe a remote start thread?) but basically since there is almost no load at idle the engine doesn't warm up right anyway.

Make sure you're using oil weighted properly for your op temp range, make sure you have good oil pressure on startup, and head on your way. You can help out by keeping the RPM low until all the parts get cozy with each other again....this is usually what I try to do on my ZHP and 7.3L....wait for needle movement and then drive as normal.

Makes sense. Thanks dude!

[johnrando]

Glad that's solved. Don't forget the blinker fluid!

[danewilson77]

Glad that's solved. Don't forget the blinker fluid!

...........or the muffler grease.:shifty

[nike001]

Yeah, no warm up period for me. I get in and go... except for maybe days with ice and snow. Then I get in and turn my heated seats and defrosters on.

But as for heating up the cabin, does anyone elses fan not push out a lot? My car eventually heats up, but the fan doesn't seem to be doing much. I have to have it 1/3 areas (like forward) lit up on the HVAC and I have to put the fan speed up almost 3/4 of the way before i can feel a decent amount of air coming out..

[Meric]

Yeah, no warm up period for me. I get in and go... except for maybe days with ice and snow. Then I get in and turn my heated seats and defrosters on.

But as for heating up the cabin, does anyone elses fan not push out a lot? My car eventually heats up, but the fan doesn't seem to be doing much. I have to have it 1/3 areas (like forward) lit up on the HVAC and I have to put the fan speed up almost 3/4 of the way before i can feel a decent amount of air coming out..

Yours seems little lazy.

[johnrando]

Mine is lazy too. I have to crank it pretty high to get any decent heat. The heated seats really come in handy because of that.

[kayger12]

Yeah, no warm up period for me. I get in and go... except for maybe days with ice and snow. Then I get in and turn my heated seats and defrosters on.

But as for heating up the cabin, does anyone elses fan not push out a lot? My car eventually heats up, but the fan doesn't seem to be doing much. I have to have it 1/3 areas (like forward) lit up on the HVAC and I have to put the fan speed up almost 3/4 of the way before i can feel a decent amount of air coming out..

FSR? They can do some funky things when they go bad.

[nike001]

FSR? They can do some funky things when they go bad.

What's FSR? I've noticed that more air seems to be pushed out when I'm on the highway going faster.

I always also in 3rd gear playing around.. I hate how it squats down on one side. No LSD FTL

[kayger12]

Final Stage Resistor. Controls the blower motor. They have a bunch of different failure modes.

In my case, the fan would not blow more than medium, regardless of how high I set the fan.

http://www.bokchoys.com/differential/diy_final_stage_unit.htm

[Sockethead]

But as for heating up the cabin, does anyone elses fan not push out a lot? My car eventually heats up, but the fan doesn't seem to be doing much. I have to have it 1/3 areas (like forward) lit up on the HVAC and I have to put the fan speed up almost 3/4 of the way before i can feel a decent amount of air coming out..
Both of my e46s are like that... it seems like the last two bars are the only ones that really get it going.
BTW, if you have everything seton auto, the fan speed will increase as the car gets up to temperature so it's not blowing cold air on you... I like that.

[zj96sc]

pretty obvious but make sure your cabin filter is clean.

[nike001]

Final Stage Resistor. Controls the blower motor. They have a bunch of different failure modes.

In my case, the fan would not blow more than medium, regardless of how high I set the fan.

http://www.bokchoys.com/differential/diy_final_stage_unit.htm


Looks like I'll be trying this. As I was driving tonight, the air was on full and it was barely putting any air out. I can only relate it to putting your palm by your mouth..taking a deep breath in, and then slowly slowly exhaling it in to the palm of your hand. That's what the air speed feels like coming out of the vent

[Johnmadd]

Looks like I'll be trying this. As I was driving tonight, the air was on full and it was barely putting any air out. I can only relate it to putting your palm by your mouth..taking a deep breath in, and then slowly slowly exhaling it in to the palm of your hand. That's what the air speed feels like coming out of the vent

Lol, that's pretty weak. Had this problem in my e30, I sprayed them with electronic cleaner and no problems since then.

[nike001]

Lol, that's pretty weak. Had this problem in my e30, I sprayed them with electronic cleaner and no problems since then.

sprayed what?

[Johnmadd]

sprayed what?

The resistors.

[nike001]

The resistors.

The one in this link?
http://www.bokchoys.com/differential/diy_final_stage_unit.htm

[Johnmadd]

The one in this link?
http://www.bokchoys.com/differential/diy_final_stage_unit.htm

I guess you would have to open the module in figure E up to see the actual resistors. Let me see if I can find a pic.

[Johnmadd]

Here's what the e30 one is like, its that small exposed coil. If the previous mentioned module for the e46 contains the same type I would clean it and see how that works.

http://e30.bmwdiy.info/blower-resistor/index.html

[Johnmadd]

Here is an e46 one, its different than I imagined. But still likely your problem.
http://www.google.com/m/products/detail?client=ms-android-verizon&hl=en&gl=us&sky=mrdr&source=univ&q=e46+blower+motor+resistor&cid=16384919191621349808

[kayger12]

The E46 resistors are known to go bad and need replacing.

I would just replace it as opposed to going through the pita of getting it out and putting it back just to have to do it all over again.

Droid X. Tapatalk. Use it.

[johnrando]

Yup, I had an FSR go out on me too.

[danewilson77]

Yup, I had an FSR go out on me too.

Me too... On the old car.

HTC Thunderbolt+TT

[kayger12]

Me too... On the old car.

HTC Thunderbolt+TT

Same here.

Droid X. Tapatalk. Use it.

[nike001]

Ok thanks guys, I"ll be tackling this over break.

I'll report back after I get this fixed. Gotta give me some time, as I'm short on funds currently :P