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Replacing throttle body coolant hoses?

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So, I seriously replaced all of the coolant hoses I’m aware of, besides those on the throttle body. I was always dreading what’s lurking under the ominous intake manifold and now I know, there’s a couple of coolant hoses that attach to the throttle body. I can barely see in there, but from what I can see, the hoses look old and crusty. The area in question also looks crusty and may/may not be leaking coolant. I suppose I won’t know unless I take off that intake and look around.


The reason I’m curious, is that I’m still getting air bubbles in the overflow tank and still smell coolant from the heater/climate control. I’ve replaced everything else it seems and can’t find any leaks. This seems to be the only place I haven’t investigated. Anyways, how dumb would I be to attempt to get in there? It looks like a mess of hoses, and bolts. Getting the TMIC off is no sweat, but taking off the intake, I fear breaking sensors and forgetting where vacuum hoses go. Any advice would be appreciated.

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No, I smelled around and checked for wetness inside and on the carpet and nothing. It only really happens when I “step on it” so that’s why I suspect the TB.. maybe my logic is wrong, and a little coolant smell is par for the course, but I’m not a fan of the occasional whiff of coolant.
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Well that's good to hear. not a heater core.


You'll need a good bright light see down between the tmic and the intake.


Hey may be you could lock wire the hose if you can't tighten the hose clamp. Like I did years ago to the fuel line under the intake manifold by #2 cylinder. You should be able to see what I did in my click here link. I think there's a picture of the lock wired hose.


FWIW, I noticed a whiff the other day in the wagon, couple day's later I noticed a little greenish corrosion at the top radiator hose...I'll have to tighten that someday...if I don't forget, again.

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.


Engine Build - Click Here

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I actually just had a problem like this. driving normally around don't smell anything everything seemed good. When I get on it pretty good after I stop I could smell coolant.


smell wasn't coming in from the inside but definitely being blow in from the engine bay.


First thing I noticed one of the 90 degree hoses to the oil cooler had a slight leak. It would drip down on the exhaust manifold and burn up. It was so small the only was I found it was looking at my oil filter I saw dried coolant on it and that was the only hose around. Turned the car on drove it around for a bit and got back under there. I could see coolant around the inside of the hose.


After replacing that still had a smell. Not as bad as before but still I noticed it. Looked around the engine bay only few things I noticed that could be the problem. The upper rad hose had driver coolant around the part on the radiator. So just replaced that just in case.


Also the overflow coolant hose that runs from the turbo reservoir to the overflow tank. On the outside it smelt like coolant. I bought a wrx reservoir and it came with the line. Not sure if the smell was just dried coolant on it or if it was just going bad. The whole line didn't smell until it got to the little metal line that goes to the radiator.


So far I haven't smelled anything else. But I don't get on it that much so time will tell. I know you said you replaced everything besides those heater hoses but I would double check everything anyways just to be sure. Looking for dried coolant or anything wet. If you do see any dry coolant clean it up drive it for a few days see if it comes back.

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I definitely replaced the entire oil cooler hose and line assembly going to the water pump. Including the water pump, line, with ALL the hoses. The hose that attaches to the water pump was shorter than I liked it to be, but I got them lined up and clamped properly.


FWIW, I opened the turbo expansion tank and looked in there, and it’s completely full! Which has never been the case since I got the car. I also squeezed the upper rad hose and it’s full as well. Also a first! So, I capped it up and drove it. No more sloshing noise behind the dash, and no more smell! I have yet to check for bubbles when I stop, but is it possible the system finally leveled itself out, and that smell is just residual air pockets working their way out? I don’t know.. like I said, when I did the timing belt, I went around and replaced every damn hose I could see. Including the hoses stuck on the bottom of the expansion tank. From what I can see, the only two hoses I didn’t get are on the throttle body... unless there’s more buried under the intake manifold I don’t know about.


Pressure test is the last option, and seems like a warm weather project. Hopefully it’s all good. Any more smell tho, and I’m going to have to pull the belly pan and investigate. Maybe it’s all good? A little more time will tell.

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Have you pressure tested the coolant system? If not, have a shop take a look at it or purchase a tester and check for yourself. Also for the record, removing the intake manifold is not necessary to reach the throttle body coolant hoses.


Good to know I can get at them without removing the intake. Although, I’m sure I’d have to drain the coolant and tear up my hands in the process. Seems like a last resort, warm weather project.

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