genphreak
01-26-2008, 05:50 PM
Has anyone any experience with the throttle body thermostat? It mounts into the airbox and regulates coolant flow through the Throttle Body housing to allow for the outside air being cold.
I'm talking about this thing: Part #13541730682
https://www.bavauto.com/assets/product_images/hardpart/13541730682.jpg
It is item 10 in the realoem context diagram (below). Apparently it stops the Throttle Body icing up
I think this is faulty on my M50 as the TB is boiling hot (can't even touch the TB) once th car is at temperature. Locally, temperatures here do not get cold enough for this feature to be needed as we never get anywhere near freezing here unless I got to the mountains.
This thread was helpful: (thanks Ryan and Bill R.)
http://www.bimmernut.com/forum/showthread.php?t=1195&highlight=thermostat+%22air+box%22
Occasionally the engine backfires into the intake manifold when starting- especially if the car is started whilst still warm. This usually blows a hose off the intake and pumps grey smoke everywhere under the hood.
Lots of hoses were cracked up originally, so I have been chasing intake leaks as the motor was running very badly when I got the car. There were lots of split-ends and broken connectors like the one that seals the ICV hose to the intake manifold. The TB boot was even split and there was plenty of signs of previous dodgy vacuum fixes (like cable ties over split hoses).
Origianlly I checked fuel pressure, plugs and changed the oil and coolant. There is no coolant in the oil or oil in the radiator, no smoke at any time- even on hard kick down when it is running shittily. The cooling system works as it should and pressurises fine. Now I have changed most of the hoses and connectors, but it still doesn't run right. The motor bogs down under throttle and idles very slowly. It is is often quite rough- especially once it is at temperature.
However, just to keep this home troubleshooter on his toes, occasionally the engine runs really well.
The rough running when warm I think is a hint about the TB. The occasional backfire into the manifold at warm startup (it doesn't at any other time, such as under load) has led me to think I should try bypassing the coolant from the TB altogether. I figure a boiling intake can't help her much.
Searching online for similar troubles others might have had, it became clear that this issue is not common amongst M50 owners. However this strange plumbing is common to M50 powered e36 and e34s.
Anyhow... surely super-heating the TB can be avoided altogether? The reason I ask as opposed to just do, is that realoem shows no thermostat on the airbox on ealry M50s. On these 89-90 model cars the hot coolant is seemingly piped straight form the head to the TB all the time... which seems crazy, but makes me think bypassing coolant from the TB is a bad thing to do- and I'd like to be able to go to the mountains without getting the throttle plate stuck.
Any thoughts would be greatly appreciated before I give this a go... Thanks in advance, Nic
I'm talking about this thing: Part #13541730682
https://www.bavauto.com/assets/product_images/hardpart/13541730682.jpg
It is item 10 in the realoem context diagram (below). Apparently it stops the Throttle Body icing up
I think this is faulty on my M50 as the TB is boiling hot (can't even touch the TB) once th car is at temperature. Locally, temperatures here do not get cold enough for this feature to be needed as we never get anywhere near freezing here unless I got to the mountains.
This thread was helpful: (thanks Ryan and Bill R.)
http://www.bimmernut.com/forum/showthread.php?t=1195&highlight=thermostat+%22air+box%22
Occasionally the engine backfires into the intake manifold when starting- especially if the car is started whilst still warm. This usually blows a hose off the intake and pumps grey smoke everywhere under the hood.
Lots of hoses were cracked up originally, so I have been chasing intake leaks as the motor was running very badly when I got the car. There were lots of split-ends and broken connectors like the one that seals the ICV hose to the intake manifold. The TB boot was even split and there was plenty of signs of previous dodgy vacuum fixes (like cable ties over split hoses).
Origianlly I checked fuel pressure, plugs and changed the oil and coolant. There is no coolant in the oil or oil in the radiator, no smoke at any time- even on hard kick down when it is running shittily. The cooling system works as it should and pressurises fine. Now I have changed most of the hoses and connectors, but it still doesn't run right. The motor bogs down under throttle and idles very slowly. It is is often quite rough- especially once it is at temperature.
However, just to keep this home troubleshooter on his toes, occasionally the engine runs really well.
The rough running when warm I think is a hint about the TB. The occasional backfire into the manifold at warm startup (it doesn't at any other time, such as under load) has led me to think I should try bypassing the coolant from the TB altogether. I figure a boiling intake can't help her much.
Searching online for similar troubles others might have had, it became clear that this issue is not common amongst M50 owners. However this strange plumbing is common to M50 powered e36 and e34s.
Anyhow... surely super-heating the TB can be avoided altogether? The reason I ask as opposed to just do, is that realoem shows no thermostat on the airbox on ealry M50s. On these 89-90 model cars the hot coolant is seemingly piped straight form the head to the TB all the time... which seems crazy, but makes me think bypassing coolant from the TB is a bad thing to do- and I'd like to be able to go to the mountains without getting the throttle plate stuck.
Any thoughts would be greatly appreciated before I give this a go... Thanks in advance, Nic