No heat unless moving??

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ColoDisco2

Guest
Ok here's another problem I am having with Disco (aside from the check engine light). I seem to be having a heat problem of some sort. In the morning I can go out and start the truck and let it warm up. Only thing is that heat doesn't come out of the the vents unless I'm moving. The truck will be warm I'll cruise down the road stop at a light and sure enough the heat coming out of the vents turns cold?? When I continue on heat will come out again?

Anyone know what's going on here?

thanks
 
M

madmole

Guest
Sounds like the fan isn't blowing and you only get flow when movement is pushing air into the cab

Can you hear the fan run when you change the fan speed?
 
C

ColoDisco2

Guest
the fans work ok. they increase fine from low to high on heat and AC.

the heat just stops when I'm not moving???
 

RVRSRVC

Well-known member
May 7, 2004
1,163
0
Elizabethtown, PA
www.roverlab.com
Also, low coolant will prevent the coolant temp sensor (for the computer, not the gauge) from sending the correct reading to the engine computer. This will set a check engine light fault code also.
Hope this helps!
 
C

ColoDisco2

Guest
Ok checked the coolant levels and they where a bit low, maybe a quart. Still no go though. The A/C actually does not blow cold now either. I thought it did but the other day when I really needed it, it for sure wasn't cold. So as of now the problems are...

1. No A/C
2. Heat only when moving (fans for the vents do work though)
3. Service Engine Soon light is on with ODB II codes P1172 & P1175
4. My gas mileage seems to also be worse then usual. I got about 320 miles off my last tank of gas and most of that was highway driving.

The Service Engine light came on after the last time I went wheeling. I had a couple stream crossings and upon further review I found out a little water got into the air intake. Nothing much just droplets up past the filter. I say nothing much but I really don't know what that will effect and how much it can effect it. The oil looks fine. I did spray out the MAF with electrical cleaner and reset the computer by disconnecting the battery. However after about 60-75 miles the Service engine light comes back on.

Thanks for all the help so far. If anyone has any info that could point me towards something to look at that would be great.
 

marc olivares

Well-known member
Apr 20, 2004
3,535
0
your code are not related to your heat/ac issue, but do explain your poor fuel economy.
your codes are:
P1172 oxygen sensor system too rich faults banks A&B
P1175 ? never seen this code relating to rovers, for ford it's a cam/rotor fault
are you sure it wasn't a P1176 code that would make more sense and would suggest that you smoked your MAF durring your water crossing.

come to think of it, you may have shorted the controls to the heat /ac unit as well.
 
C

ColoDisco2

Guest
Anyone know a good place to order an MAF?
 
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C

cora

Guest
no heat

WE also had no heat when stopped. Do you have a gurgeling sound behind the dash?

We took the car in and they advised there was one thermostat not operating correctly. We had a leak in the head gasket. Fixed that to stop the coolant leak. The pressure through the heater core was not up to 100% operating specs. They suggested the coolant had not been changed enough so there is a partial blockage. At this point the heater is working quite well but we should take it to a radiator repair for the real fix.

We had driven through a few streams prior to noticing the heater did not work.

Other issues - The D2 is new to us and we had not needed the heater before. The pins on wiring harness to computer were loose so the codes could not be read.

After our repair job we went home (3hours away). Then the Service engine soon light came on.

Cora
 

hywy61

Well-known member
May 25, 2004
725
0
atlanta, ga
rover connection sells MAFs

I sprayed mine with electrical cleaner and the service engine went off for a while. About 1K later - back on again......

www.roverconnection.com sells them but i have never ordered one from them but probably will be soon.
 
E

EXPetrush

Guest
i would bet your thermstat is not opening or not completely... there is a small bypass hole in the thermostate that will allow some water to flow thru. It makes some sense that your only heat is when you are driving (higher rpms = more water pump flow = heated coolant getting to your heater core... its worth the $14 & 30 min to change out old therm...
 

Windycity_Rover

Well-known member
Dec 4, 2004
72
0
53
Da Windy City
Thermostat

I just delt with a bad thermostat. After replacing the radiator and hoses my OEM thermostat from the dealer took a dump. Had similar problems with the heat and gurgle. I replaced the t-stat and it was all fixed. Spend a quick 15 bucks and start there and make sure you keep topping up the coolant tank. It will take time to get that air out. Drive it 20-30 minutes.
 
P

padreisla

Guest
I am going to have to try the thermostat, I have a 99 Disco II and I am getting the P1172 & P1175, gurgling and noticed that the fluid level was a little low. I have replaced the MAF & both of the front O2 sensors. I would of never thought of the thermostat, I will post back on here next week, after I get a chance to change it out. Thanks for the information.

Joey
 
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padreisla

Guest
I am guessing that you are talking about bleeding the air out of the system using the screw that is in the hose that is on top of the fan shroud. If I had a pic I would post it here, but it is basically the hose that runs over the top of the fan shroud, it has what looks like a thumb screw on it.

Joey