Curious coolant hose routing for the 32 valve
10-25-2007, 06:31 PM
#16
Chronic Tool Dropper
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Stan--
When you removed the temp senders, was the reservoir cap in place? If so, there would be no coolant escape even if there was liquid right at the top of the bridge. Of course a lot depends on the relative temp of the coolant when you do the work. Think about how you can pick up a straw full of water by dipping the straw into water, then plugging the top of the straw before withdrawing the straw. So long as the straw is less than about 32' long (with pure water...), it shouldn't be a problem. Atmospheric pressure holds the coolant inside the bridge unless that same pressure is applied to the reservoir. Generally, the cooling system is under a very slight vacuum (relative) after the car is heated and cooled. In fact, removing the coolant temp sensor without removing the reservoir cap will almost undoubtedly --cause-- an air pocket in the bridge as that vacuum is equalized with air drawn in through the sensor port.
When you removed the temp senders, was the reservoir cap in place? If so, there would be no coolant escape even if there was liquid right at the top of the bridge. Of course a lot depends on the relative temp of the coolant when you do the work. Think about how you can pick up a straw full of water by dipping the straw into water, then plugging the top of the straw before withdrawing the straw. So long as the straw is less than about 32' long (with pure water...), it shouldn't be a problem. Atmospheric pressure holds the coolant inside the bridge unless that same pressure is applied to the reservoir. Generally, the cooling system is under a very slight vacuum (relative) after the car is heated and cooled. In fact, removing the coolant temp sensor without removing the reservoir cap will almost undoubtedly --cause-- an air pocket in the bridge as that vacuum is equalized with air drawn in through the sensor port.
10-26-2007, 05:42 AM
#17
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It should be easy to check correct routing from brochure pictures. If all show hose one way or another its safe bet to put own cars hose same way. Even if there isn't any real difference engine bay at least looks stock.
10-26-2007, 12:28 PM
#18
Chronic Tool Dropper
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Erkka--
My car came to me unmolested in the engine bay with 22k on it. The routing in the picture I posted is (still) what was shipped from the factory. Stan opened the discussion on this when we were visiting the engine bay at Sharktoberfest. It's something he's put some good thought into. It's possible that air bubbles in the top of the bridge would disspate more quickly if the vent hose is routed over the top radiator hose. I'm just not sure that there's really a problem, and therefore if there needs to be a cure.
Sometime during the engine design process, the Porsche engineers decided that the vent hose was needed. Remember that these same engineers work in rotation at M-B, Audi, and Porsche as the project loads demand. The vent hose may have made perfect sense in an M-B car where the reservoir sits higher and/or the slope of the hose is more carefully managed. With the low hood and the tight fit over the shock tower, it just doesn't make sense to me in the 928.
My car came to me unmolested in the engine bay with 22k on it. The routing in the picture I posted is (still) what was shipped from the factory. Stan opened the discussion on this when we were visiting the engine bay at Sharktoberfest. It's something he's put some good thought into. It's possible that air bubbles in the top of the bridge would disspate more quickly if the vent hose is routed over the top radiator hose. I'm just not sure that there's really a problem, and therefore if there needs to be a cure.
Sometime during the engine design process, the Porsche engineers decided that the vent hose was needed. Remember that these same engineers work in rotation at M-B, Audi, and Porsche as the project loads demand. The vent hose may have made perfect sense in an M-B car where the reservoir sits higher and/or the slope of the hose is more carefully managed. With the low hood and the tight fit over the shock tower, it just doesn't make sense to me in the 928.
10-26-2007, 02:33 PM
#19
Team Owner
Thread Starter
my guess for the engine bleed hose is due to the fact that the radiator is lower than the block and since this is so then a hose of some sort was introduced to help the engine coolant system be a self bleeding system, even though there is a bleed hose on the radiator if theres air in the block the rad bleed hose wont let it out, IE air wont flow downhill
10-26-2007, 03:03 PM
#20
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