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Thermostat gasket keeps leaking...

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Old Aug 8, 2010 | 03:02 PM
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Default Thermostat gasket keeps leaking...

Hello everyone,

Must be like the 4th or 5th time I've had to replace this. I've used the sealant plus the paper gasket this time because the sealant alone wasn't cutting it.

However this time I've noticed a few odd things about the car. First off, it's still leaking a little bit of coolant in the thermostat housing area, and at the same time I've noticed this sort of brown smudge of material and accumulates around there. I've checked the oil for any signs of coolant presence and it's clean as can be, and certainly doesn't smell sweet. The temperature when the car is running is good (considering I live in the desert climate of AZ) it never goes over 210 degrees idling in hot traffic.

Also a few weeks ago, I popped open the radiator cap and took a look inside the radiator and noticed some dirt or particles that is resting in the coolant. Now...the radiator is relatively new (replaced in Nov of 09') as well as the thermostat, radiator hoses, and radiator cap. I've swapped out the coolant with new one, but I am just confused as to why there's dirt in the system already. Should I do a coolant flush and get the crud all out? And if so, how should I go about doing that to give it a good clean run through.

Anyway, that's all I've got for now. School starts up soon for me again so I want to make sure everything is in good working order before then.

Thanks!
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Old Aug 8, 2010 | 06:12 PM
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Any ideas?
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Old Aug 8, 2010 | 06:16 PM
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You sure its leaking from the housing and not the hose?
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Old Aug 8, 2010 | 06:21 PM
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Not sure about the leak, but I would flush the coolant system and flush it good.
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Old Aug 8, 2010 | 06:25 PM
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^x2 DEF give it a flush.. crap and gunk in your coolant is NEVER good. It will clog that new rad faster then you can say "DAMMIT". As for the leak, make sure you check the upper hose and that it is sealing around the housing. Also, is it a new housing? Check the housing itself for ANY cracks or such.

Edit: To further pinpoint the issue, are you being VERY careful when tightening those bolts? T-stat housings aren't the toughest things ever, and if they are over tightened or tightened to quickly, they can crack.
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Old Aug 8, 2010 | 07:30 PM
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Here's a pic of the best flushing tool ever (IMHO).....just attach it to a garden hose. Flush the heater core, the cylinder head/engine block and radiator. DO NOT flush one into the other, flush them separately/individually.
Attached Thumbnails Thermostat gasket keeps leaking...-002.jpg  
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Old Aug 8, 2010 | 07:33 PM
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is your thermostat housing cracked?
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Old Aug 8, 2010 | 07:43 PM
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Originally Posted by djb383
Here's a pic of the best flushing tool ever (IMHO).....just attach it to a garden hose. Flush the heater core, the cylinder head/engine block and radiator. DO NOT flush one into the other, flush them separately/individually.

Im liking that. I was always worried about doing a flush due to fear of the heater core taking all the gunk. Where did you get that? Does it just fit in one heat core hose, and then have the other house point into a bucket?
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Old Aug 9, 2010 | 06:45 PM
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Okay...I drained the radiator and I am afraid that what I have found is not good at all.

Right at the base of the radiator cap, I stuck my finger down and just took a wad of what appeared to be sludge from the bottom. I don't know how this got in there, especially since both the radiator and the cap are new.

Right now, the coolant is still draining out and I bought about 4 gallons of distilled water. I just want to make sure I get all of this crud OUT before I refill it with anything.

I don't think me pouring distilled water into the radiator is going to remove these deposits, so I am thinking of taking a garden hose and just blasting it down but I want to know if this is safe to do so before I do it.

Thanks...
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Old Aug 9, 2010 | 08:39 PM
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check your bottle, may have sludge in the bottom of that too..
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Old Aug 11, 2010 | 01:11 AM
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Okay guys I am going to need some strong advice here.

I flushed the radiator about 3 times total, and just when I thought everything was clear, I decided to fill her up again with some coolant. After driving around...I noticed that she sprung a leak or something at the bottom of the radiator. She was leaking out coolant at the parking lot, and a little bit at home.


Not only that, the reservoir bottle is pretty dirty at the bottom too, and the coolant in the radiator is already dirty again.

When I drained the old coolant out, it was pretty filthy, and when I pulled the rest of it out from the bottom radiator hose, there was a lot of dirt in it.

Does anyone have any ideas on how to fix this?
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Old Aug 11, 2010 | 01:41 AM
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Try a chemical flush not just water. I am told the chemical flushes break up and remove mineral deposits and the gunk better. I have heard of people needing to flush theirs out 6+ times to get everything out.

Last edited by NewXJaddict; Aug 11, 2010 at 01:46 AM.
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Old Aug 11, 2010 | 10:17 AM
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I dont know if anyone said anything about this but check to see if the housing is warped...that will cause it to leak ive had that problem
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Old Aug 11, 2010 | 11:18 AM
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Is your thermostat housing stock? If so, all 4.0 years came with weak aluminum housings that will distort or bend if tightened to tight. They can also crack and sometimes those ears that the bolts go through will break off. My advise would be to get a aftermarket cast iron replacement. The ones Ive bought were from Schucks, now OReilleys, and were very affordable, around $10 or $11. And the cast iron housings will not bend, break, or distort.
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Old Aug 11, 2010 | 08:04 PM
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I've been struggling with this same problem (the leak at the t stat housing) for a week or so now. I have replaced that gasket a few times too, but it still leaks out.

if the housing was warped would you be able to tell? it kind of just seems like it won't get tight against the block on the right bottom side where its furthest from both bolts. why did they only have those two bolts anyway? why not a third?

anyway, if a new housing is only ten bucks, should the op and I just do that and skip trying to use RTV and a gasket?
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