Some Troubles... '87 928S4 5spd
#16
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Stop by the local parts store and free-rent their cooling system pressure tester. Use it to put some pressure in the system, no more than 14 PSI or so though (normal cap relief pressure). With pressure on it, you'll find the leak(s) quickly.
Cooling system hoses, especially the smaller ones that aren't the top and bottom radiator hoses, are too often ignored until they fail. On some regular basis, they really do need to be replaced. I swap them all at every other timing belt service. The plastic coolant reservoir does get hard and brittle with age. Is yours old and brown? While all the coolant is drained, and for MUCH easier access to the hose between the reservoir and the Y-pipe on the fenderwall, remove the old one and replace with new. The reservoir cap is on my 'every timing belt change' schedule. Original Behr caps are relatively inexpensive from our vendors. Thermostat and seals at the same time. Splurge! Lessens the chance that the cooling system will drain itself at some less convenient time, like on the side of a lonely desert highway in the summer sun.
Cooling system hoses, especially the smaller ones that aren't the top and bottom radiator hoses, are too often ignored until they fail. On some regular basis, they really do need to be replaced. I swap them all at every other timing belt service. The plastic coolant reservoir does get hard and brittle with age. Is yours old and brown? While all the coolant is drained, and for MUCH easier access to the hose between the reservoir and the Y-pipe on the fenderwall, remove the old one and replace with new. The reservoir cap is on my 'every timing belt change' schedule. Original Behr caps are relatively inexpensive from our vendors. Thermostat and seals at the same time. Splurge! Lessens the chance that the cooling system will drain itself at some less convenient time, like on the side of a lonely desert highway in the summer sun.
#17
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If replacing the coolant tank, get one of Carl's aluminum ones. You'll never need to replace it ever again. Note that his does not come with a new cap, but as DB says definitely get a new cap, too.
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I second the Carl aluminum one. check your radiator also. will crack along where the tanks and tubes meet. replace the small diameter hoses like Dr. Bob says.
All will be well soon.
All will be well soon.
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Wanted to follow up and tell you guys what it turned out to be. I made some time this morning to look for the leak. Figured the car would be down all week while i pressurized system, ordered hoses etc, but it turned out to be easier than I'd feared. After taking the airbox housing out and shining a light in there, I was inspecting the heater valve connection (which looked good) and just by moving the hoses around slightly, the leak became apparent and the hose connecter that holds the hose from the front of the engine where it connects to the other hose that runs into the firewall just crumbled and started leaking more. It was a mess to get the deteriorated pieces of plastic hose coupler out of the old hoses, but i cleaned and flushed them out as much as I could. The hoses themselves look like they are overdue for replacement too, especially the lower one from the engine, but they were supple enough to reuse for now to get her running. The tank doesn't appear to be leaking but looks pretty cooked too, so I'll replace that soon. For now this was just field triage to verify that that was the problem and get her running so I can order more parts and schedule some time to do a refresh in a better garage with all my tools. The oil looked fine too so that was just me being paranoid. Drove her to work after and kept checking for leaks and all looks good so far. Attached some pics of what I found and the new coupler:
![](http://i52.photobucket.com/albums/g22/Gullstrom/Porsche_928/chris-928s4_94-1.jpg)
![](http://i52.photobucket.com/albums/g22/Gullstrom/Porsche_928/chris-928s4_95.jpg)
![](http://i52.photobucket.com/albums/g22/Gullstrom/Porsche_928/chris-928s4_96.jpg)
New 19mm hose connector:
![](http://i52.photobucket.com/albums/g22/Gullstrom/Porsche_928/chris-928s4_93.jpg)
![](http://i52.photobucket.com/albums/g22/Gullstrom/Porsche_928/chris-928s4_92.jpg)
Thanks again for the great suggestions guys!
![](http://i52.photobucket.com/albums/g22/Gullstrom/Porsche_928/chris-928s4_94-1.jpg)
![](http://i52.photobucket.com/albums/g22/Gullstrom/Porsche_928/chris-928s4_95.jpg)
![](http://i52.photobucket.com/albums/g22/Gullstrom/Porsche_928/chris-928s4_96.jpg)
New 19mm hose connector:
![](http://i52.photobucket.com/albums/g22/Gullstrom/Porsche_928/chris-928s4_93.jpg)
![](http://i52.photobucket.com/albums/g22/Gullstrom/Porsche_928/chris-928s4_92.jpg)
Thanks again for the great suggestions guys!
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Glad you found it. Is that a standard fitting? Doesn't seem to be any reason for a coupling in the middle of a hose. Maybe a previous reoair of some sort?
Good luck,
Dave
Good luck,
Dave
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Glad you got it sorted. Living in Boston, you're probably going to need to change your hoses more frequently than someone living in Cali/Florida, etc. The harsh winters are tough on plastics and rubber.
At some point, I'd also take the time to pull the fan and radiator to clean out the crap between the rad and condenser. The rad doesn't have to come all the way out. It is shocking how much junk ends up there in a short amount of time. At this point I'd consider this an every-other-oil-change procedure.
At some point, I'd also take the time to pull the fan and radiator to clean out the crap between the rad and condenser. The rad doesn't have to come all the way out. It is shocking how much junk ends up there in a short amount of time. At this point I'd consider this an every-other-oil-change procedure.
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Glad you got it sorted. Living in Boston, you're probably going to need to change your hoses more frequently than someone living in Cali/Florida, etc. The harsh winters are tough on plastics and rubber.
At some point, I'd also take the time to pull the fan and radiator to clean out the crap between the rad and condenser. The rad doesn't have to come all the way out. It is shocking how much junk ends up there in a short amount of time. At this point I'd consider this an every-other-oil-change procedure.
At some point, I'd also take the time to pull the fan and radiator to clean out the crap between the rad and condenser. The rad doesn't have to come all the way out. It is shocking how much junk ends up there in a short amount of time. At this point I'd consider this an every-other-oil-change procedure.
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![](http://i52.photobucket.com/albums/g22/Gullstrom/Porsche_928/928-coolingsystem-PET.jpg)
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The circled connector is a different one, it is part of one of the two small hoses coming out of the coolant reservoir to the front of the engine. The connector in your picture is not standard as far as I know. The hose in your picture with the connector is the hose from the metal y-tube under the coolant reservoir to the heat exchanger in the car. You can see the y-tube in the diagram you posted. The hose and y-tube can be seen in PET 813-10. It can be replaced pretty easily although it is a bit a of chore to connect it to the y-tube since there is not too much space to work (so what else is new
).
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