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They call me Garrett
98 RBP V4 STi Swapped RS
Joined
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4,096 Posts
Discussion Starter #1,122
Alright. So.

Lower rad hose on the engine side was pretty loose. No idea why.

It was dripping the SLIGHTEST amount but I bet it was plenty loose for lots of air to get sucked into.

We'll see if that does anything when I burp it tomorrow.

:crossesfingers:
 

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They call me Garrett
98 RBP V4 STi Swapped RS
Joined
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4,096 Posts
Discussion Starter #1,123
Alright so I think I have logically figured it out.

Lower rad hose loose = SLIGHT coolant loss, but LOTS of air into system. When air is introduced to the more or less closed coolant system, the coolant can't be there so it is displaced to the overflow tank. Also the air would go directly through the HVAC first if this was the case. This is 1 part.

Since the lower rad hose was the one loose, most air would be getting into the system via lower rad hose and until there was enough coolant displaced by the air, the radiator would still be dissipating heat so the car wouldn't overheat. Also, it would mean that the lower rad hose gets filled with air first... which is right near the thermostat. When the air gets into the system it is much cooler than the coolant (water dissipates much more heat than air) and as it gets hotter, like when driving on the highway or when doing pulls, the air expands in the system. When that happens the air would surround the thermostat at a cooler temperature than the coolant and close up the thermostat thus overheating the motor. This is the second part.

When the system gets pressurized the hoses expand a bit, and with an already loose line, it would allow for more air to be pulled in, also more coolant to come out, but that would be replaced by air anyways. This is the third part.

So the fact that the car overheated on the highway while hauling ass and the only real leak seemed to be from the overflow tank makes sense. It also makes sense that I still had quite a bit of coolant left in the motor after it sat for a few days. It also explains why I hear tons of bubbles in the HVAC once the car warms up. It also, ALSO explains why this morning i squeezed the lower rad hose and a big air bubble popped to the top of the expansion tank.

Everything makes sense, let's see if it's fixed.
 

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Impreza Actual
2001 RS-T
Joined
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1,276 Posts
I hope that was it and I hope you have a long life on that motor. But on the other hand I want for there to be a reason for you to rebuild and at minimum use some better rods and oil pickup lol.
 

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They call me Garrett
98 RBP V4 STi Swapped RS
Joined
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4,096 Posts
Discussion Starter #1,127
glad you found it!
Bah beat me to it, was going to tell you to pressurize the system look for the leak!
Hopefully this is it. I would have been able to find it easily if it weren't winter and EVERYTHING WASN'T WET!

I hope that was it and I hope you have a long life on that motor. But on the other hand I want for there to be a reason for you to rebuild and at minimum use some better rods and oil pickup lol.
I've put almost 30k miles on it and it still runs great. I feel like I have a few tiny boost leaks though from hardened PCV lines and MAYBE a small tear in the inlet. Need to source these new parts! Ugh!
 

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Registered
V4 Sti BRP, 98LGT SP, 94SVX PW
Joined
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730 Posts
Sorry to hear.
I got mine running. Wouldn't build boost. Pulled #1 plug. BLACK.
Built a pressure tester to find 3 boost leaks. Also a small oil leak. Pulled the engine to replace all the gaskets as 1 of the leaks was the turbo compressor housing.
Hopefully I will get it sorted and boosting so I can get it tuned.

As a reference to your over heating issue.
In my RS - my radiator had a small leak that would not drip. Only when hot and under pressure would it steam out. Once cooled off it would not drip. Pressure tester to the rescue. So I 2nd the - pressure test it.

Good luck.
 

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They call me Garrett
98 RBP V4 STi Swapped RS
Joined
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4,096 Posts
Discussion Starter #1,139 (Edited)
Well my engine may be giving me problems, but at least I'll look good pushing the car home.

These came in today. Bit more curbbed than I expected, but I think my tires will cover it up a bit, and if I am really bothered I can sand and touchup. Worst wheel pictured below.

My mother brought them in from the Fedex guy and she told me that she felt so strong because she could pick up the wheel herself.



 

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auSTin
00 rsti
Joined
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2,261 Posts
So you are the guy who bought those. I had an inquired about them and everything. You got a heck of a deal on those. I was to slow
 
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