E30 Heat issues?

[johnnyBgood]

Hey guys......I just replaced the heater control valve on my brother's 88' M3.
He initially had no heat, now he has heat @ idle & low speeds during driving.
Once we reach highway speeds, the heat starts to blow warm & then cold.
We also hear something that sounds like a door actuating from under the drivers side dash while driving. As soon as we slow down, the heat starts blowing hot.......I'm thinking that a fresh air vent is opening when it is not suppose too! The system is self bleeding & has been bled.

What is puzzling is that the door seems to be actuating & not blown open from forced fresh air....also see that there is a inside air temp sensor #8 in link below & if this has something to do with it. Has anybody had this same issue!

http://www.realoem.com/bmw/showparts...80&hg=64&fg=15

I am stumped..... Tommy, Kyle, Nick, & Dave.....anybody? any ideas?


jb

[witeshark]

Seems like something is loose, but I have not seen this happen.

[johnnyBgood]

Originally Posted by witeshark

Seems like something is loose, but I have not seen this happen.

Yeah......tomorrow morning...... I am going to remove the center console & the HVAC entrance panel on the firewall & check around......


thanks Tom,

jb

[ScottinAZ]

Originally Posted by johnnybayonne

Yeah......tomorrow morning...... I am going to remove the center console & the HVAC entrance panel on the firewall & check around......


thanks Tom,

jb

Seems to me, if you think the door is opening, then the control cable may have packed it in, or the connection to the blend door could be loose. Highly unlikely that the engine is running that cool, as you can easily check the engine temp by popping the hood and feeling either the line going to the heater core, or the rad hose itself. I think there is either an issue with the new control valve (if new, unlikely) or the blend door itself

[johnnyBgood]

Well, I found the culprit.........An E30 recall....a thermostatic bypass valve installed as per recall .......check out link below:

1988 BMW M3 Recall - Recall ID 4152

part # 64 11 8 391 926

jb

[german-speed-demon]

tell your brother to just give me his ///M.

[gotKRAUT]

hahaha that's exactly what i was going to say...

[johnnyBgood]

Originally Posted by german-speed-demon

tell your brother to just give me his ///M.

If I replace that valve & his heat still does not work, he just might want to give it away....... I have had that console out 3 times already!

He sold a mint E30 325is, to buy this M3.......& I had to do a lot work to it......wheel bearings, struts, shocks,
control arms, bushings, tie rods, & links ....heater control valve, stereo head unit........

jb

[oxhead]

You may have the heater core hoses reversed. Had the same problem in my 1991 318ic.

[johnnyBgood]

Originally Posted by ScottinAZ

Seems to me, if you think the door is opening, then the control cable may have packed it in, or the connection to the blend door could be loose. Highly unlikely that the engine is running that cool, as you can easily check the engine temp by popping the hood and feeling either the line going to the heater core, or the rad hose itself. I think there is either an issue with the new control valve (if new, unlikely) or the blend door itself

I think you are on to something........I was reading in the Bentley E30 Service Manual about this.......It seems that the blend door is closing off the heater core, due to vibration.....I will be checking this next......pretty sure this is it!

thanks,
jb