Hi all,
Been chasing down a coolant leak on my 8 for a while now. Seems to be in the area of the heater core or thermostat, but can't quite nail it down. One of the throttle body coolant hoses was leaking this summer, so I capped it off, but the leak came back. Now I'm thinking the heater core hoses might be the culprit. Location under the car seems to fit with that area as well.

Ordered a new thermostat, just to rule that out (never been replaced at 90k miles now).

Any idea where to get heater core hoses? Every time I search, I get a lot of stuff for radiator hoses (I have Mishimoto hoses on there now for the radiator), but nothing for the throttle body and heater core.

Thanks,
Anthony

 

http://www.streettunedmotorsports.co...t_7805a089.htm

 

Thanks. OEM might be the way to go. Can't find nicer silicone lines anywhere (not that it's a requirement, just nice to clean up the engine bay where I can).

 

The OEM hoses Mitsubishi uses are really high quality. And you can't really see the heater hoses anyways, so not worth spending the extra money on silicone.

 

You're right about them being buried.

Just drove home and really got in there -- definitely leaking from either the thermostat and spraying on the hose or that hose itself.

I'll order the OEM hose tonight and swap it regardless (I mean, I'll have all the crap out of the way for the thermostat anyway).

Thanks.

 

I just did this job, replaced every coolant hose on the car. For heater hoses I suggest you pull the air filter and battery box. At the firewall connections for the heater hoses, they will be cemented on and you don't want to disturb the heater core, move the clamps out of the way and carefully slice the ends of the hoses with a utility knife, being careful not to notch the tubing. Work like a surgeon.

BTW, the OEM hoses come with special clamps and you will appreciate how they work.

 

Just did this job and I think it fixed it. The OEM hoses were obviously in much better shape, and those new clamps with the "preload clip" were awesome.

One area of concern was that my throttle body heater hose on the lower connection had half a barb. That is, it looked like the hose barb had been eaten away on one side. It was jagged and nasty. I sawed off the jagged part and filed down the sharp edges. I now have it looped on the block (no TB hose, one of them had burst a few months back). It had enough meat to hold onto, but I may need a more permanent solution eventually (weld on a cap or something).

Torque app showed coolant at 84C at idle and 80C when moving, so I think my thermostat is okay. After a 5 mile drive no sign of leaks. Only time will tell.

Thanks for the help all!

 

When I changed hoses at 60K I noticed some corrosion, not as bad as you are seeing, but I had to sandpaper some of the hose barbs. I just did it again at 120K and expected to find things a lot worse and things looked good. All I can think of as an explanation is I've been changing antifreeze more often. As the car ages there's been reasons to drain the cooling system and I never reuse antifreeze.

 

I waited way too long for my last coolant flush (3 to 4 years) Orange rust city in there. Did four flushes total and it's running clear/green now. Best I can tell that barb was actual erosion from grit since it's aluminum. Other barbs were just gunked up on the outside. I sanded them with some medium grit wet sandpaper to get back to bare metal.

I'm going to make sure I do the flush once a year now especially since she's getting older now.

 

The curse of a trouble free machine.