I think my head gasket just blew...
06-19-2012, 07:07 PM
#17
Pro
Thread Starter
Join Date: Jun 2010
Location: North Dallas, TX
Posts: 733
Likes: 0
Received 0 Likes
on
0 Posts
Another vote for the heater control valve. It happened to me pretty much just like that. The good news, the back of the engine, firewall, etc will be extremely clean. So, you won't get dirty (much). The bad news is you'll probably be replacing the HCV, the cycle valve and there's a sensor too. That sensor (why can't I recall it's exact name, old age maybe?) as a Porsche part is expensive. But it's a stock Bosch part that is used on BMWs as well. The BMW part is much cheaper.
Well if they were replaced that recently you're probably fine with just changing the valve (assuming that turns out to be it)...I think there are just 2 hoses - at the top right in this diagram
I think the easiest way is going to be to pull the hoses and the valve out as a single assembly...that's how I plan on removing mine anyway. So then you can take a good look at the hoses and see if you think they're OK. The lower one connects to the firewall over on the passenger side behind the cam tower.
I think the easiest way is going to be to pull the hoses and the valve out as a single assembly...that's how I plan on removing mine anyway. So then you can take a good look at the hoses and see if you think they're OK. The lower one connects to the firewall over on the passenger side behind the cam tower.
Will update shortly, folks- thank you.
06-19-2012, 07:16 PM
#18
Three Wheelin'
Another vote for the heater control valve. It happened to me pretty much just like that. The good news, the back of the engine, firewall, etc will be extremely clean. So, you won't get dirty (much). The bad news is you'll probably be replacing the HCV, the cycle valve and there's a sensor too. That sensor (why can't I recall it's exact name, old age maybe?) as a Porsche part is expensive. But it's a stock Bosch part that is used on BMWs as well. The BMW part is much cheaper.
Sentinelist, be very careful if you try to move the bracket with the sensor wires (speed and reference sensors) above the heater valve, or if you try to unplug those connectors...they can crumble away in your hands! Pics of this in the thread I linked to earlier.
06-19-2012, 10:04 PM
#20
Burning Brakes
The Vacuum timed delay valve tends to go as does that speed reference sensor as described. That darn $20 heater control valve goes and takes a number of other much more expensive parts with it.
I'll keep looking for the BMW part number for the SR sensor.
I'll keep looking for the BMW part number for the SR sensor.
06-20-2012, 12:22 AM
#21
Racer
Join Date: Sep 2011
Location: Inland Empire, California
Posts: 260
Likes: 0
Received 0 Likes
on
0 Posts
https://rennlist.com/rennforums/showthread.php?t=609869
06-22-2012, 02:43 AM
#22
Pro
Thread Starter
Join Date: Jun 2010
Location: North Dallas, TX
Posts: 733
Likes: 0
Received 0 Likes
on
0 Posts
Culprit found. Culprit replaced. 
Luckily - so far - it was the bottom heater hose connection that cracked and blew out, so I'm hoping most of the coolant didn't spray into the transmission bellhousing check hole. I saw a spot of green coolant around the hole, but looked perfectly dry inside. If it was the top end that had blown, I could be looking at a vastly different situation. I removed the top end hose myself, then it cracked inside. Vacuum operation was pretty wheezy too.
Only took about an hour to fish out the broken bits and attach the new. I assembled it whole after figuring out which hoses faced where, then stuck it into place carefully without taking the manifold off. It does take some fairly slim hands to get away with that for the firewall heater hose connection but it's very doable. I still have yet to refill the coolant and try it out, but I think I'm going back to Zims first to get a new clear reservoir so I can actually tell how much I'm running- still have the clouded up OE yellow crap can. Need at least a position sensor if not a reference sensor as well now too... I'm surprised hitting bumps in the road didn't make them fall apart. Connectors were practically like sand when I touched them. Duly noted on the BMW parts now after looking this up! Will hopefully get this finished in a few more days.
Luckily - so far - it was the bottom heater hose connection that cracked and blew out, so I'm hoping most of the coolant didn't spray into the transmission bellhousing check hole. I saw a spot of green coolant around the hole, but looked perfectly dry inside. If it was the top end that had blown, I could be looking at a vastly different situation. I removed the top end hose myself, then it cracked inside. Vacuum operation was pretty wheezy too.
Only took about an hour to fish out the broken bits and attach the new. I assembled it whole after figuring out which hoses faced where, then stuck it into place carefully without taking the manifold off. It does take some fairly slim hands to get away with that for the firewall heater hose connection but it's very doable. I still have yet to refill the coolant and try it out, but I think I'm going back to Zims first to get a new clear reservoir so I can actually tell how much I'm running- still have the clouded up OE yellow crap can. Need at least a position sensor if not a reference sensor as well now too... I'm surprised hitting bumps in the road didn't make them fall apart. Connectors were practically like sand when I touched them. Duly noted on the BMW parts now after looking this up! Will hopefully get this finished in a few more days.
06-23-2012, 01:21 AM
#25
Pro
Thread Starter
Join Date: Jun 2010
Location: North Dallas, TX
Posts: 733
Likes: 0
Received 0 Likes
on
0 Posts
06-23-2012, 11:10 AM
#28
Addict
Rennlist Member
Rennlist Member
Chris, Before replacing you reservoir tank,do some searching on here. There was a thread a few years back on cleaning it with Folgers coffee. I haven't tried it but a few did and said it worked.
Fred
Fred
