No heat at highway speeds //M6

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Chris Wright

Post by Chris Wright »

sansouci wrote:I guess I'm dense: what is an MTC?
A Manufacturer of substandard parts, much like "Uro".
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Da_Hose
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Location: Santa Ana, CA.

Post by Da_Hose »

It would be great if you could break down a Bosch part, take good pics. and maybe even get some measurements.

Jose
1987 M6 - My dream car
Chris Wright

Post by Chris Wright »

Da_Hose wrote:It would be great if you could break down a Bosch part, take good pics. and maybe even get some measurements.

Jose
I had a quick look and couldn't find the old one right away. I'll have a better look this weekend.
six shooter

Blistering cold here....

Post by six shooter »

Gotta shout-out to Barry for fixing me up with a damn nice used
heater valve. Installed it about a month ago.

Very nice and toasty warm in the Bavarian Ferarri. It was very cold other
morning and I had it at Max temperature. Whoa, that nearly melted my
rubber soles..
After doing a autopsy on the 1987 valve, the solenoid was weak and could not
hold the valve in place.
I have the plastic unit if someone has a cracked housing.
Free plus shipping.

Gotta help a brother stay warm
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Da_Hose
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Joined: Fri Mar 07, 2008 8:15 am
Location: Santa Ana, CA.

Post by Da_Hose »

I'll take that housing. I tried fixing the MTC valve I have and no dice. It still closes off over 2500 rpm.

I will move forward with a direct acting valve conversion and using an OEM housing could let me keep the check valve and use the stock mounting points easily.

I'll PM you.

Jose
1987 M6 - My dream car
JoelR
Posts: 49
Joined: Sun Mar 09, 2014 4:19 am
Location: DFW (Plano) Texas

Post by JoelR »

Big thanks to all who have contributed to this topic. My Bosch valve had a tear in the diaphragm, so I bought the MTC valve. It exhibited the same symptoms (no heat above 2k rpm), so I was glad to read about swapping the plastic spacer from the Bosch to the MTC. It works like a champ now!

The Bosch spacer itself has a larger inner diameter (as previously stated), but it also has three ridges that keep it centered on the shaft, as opposed to a perfectly smooth bore.

(Also, in case you are contemplating doing this and did not already know, the heater valve is located in such a way that you do not have to drain the coolant to remove it. Two small bolts and 4 small screws is all you have to remove. However, it is a bit tricky to get the E-ring back on after swapping the spacers - just be patient.)

Joel
1983 633CSi 5-speed Black & Tan
2008 X5 4.8i
2004 MINI Cooper S 6-speed
2001 Z3 3.0i 5-speed
DFW Texas
GazM3
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Joined: Wed Oct 26, 2011 12:55 pm
Location: Melbourne, Australia

Post by GazM3 »

I'm revisting this thead.
Mine is doing same (closing at 2000rpm). Has anyone replaced the valve with a N.O. 12v solenoid valve?

It's really annoying having the heat stop when cruising in cold weather.
Also what is the pipe size as it's a bit of a pain to measure the valve as I have the plenum in the way.
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