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Black "gunk" in coolant reservoir tank

Old 09-03-04, 06:57 AM
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Unhappy Black "gunk" in coolant reservoir tank

This can't be too good... My coolant buzzer beeped yesterday and I pulled over thinking that it just needed to be topped off b/c I did some work on the car this weekend.

Anyways after topping it off, I checked the dipstick in the coolant reservior. It's covered in black gunk that looks like dirty oil. It litteraly looked like I stuck the stick in some mud or something. Is this as bad as it seems? Anybody have any experiance with this before?

Thanks.

-Matt
Old 09-03-04, 08:42 AM
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It's fairly common. Clean it off and make sure to flush your coolant on a good regular basis.
Old 09-03-04, 08:51 AM
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cool... so it's not oil?
Old 09-03-04, 08:52 AM
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Every FD I've ever seen or worked on, and every FC I've seen and worked on have had black gunk in the overflow tank. It's either oil or combustion gasses - I think it's just the nature of the rotary engine, the water seals aren't perfect, they let just a little bit in.

Nothing to be worried or concerned about.

Dale
Old 09-03-04, 08:58 AM
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In a related question, is the overflow tank supposed to have much in it at all? I have the gunk as well, but nothing else in the tank. I've poured some water in it before and it just seems to drain out the bottom somewhere. I dont have any coolant issues though so I'm not sure if I should dive into that or not.
Old 09-03-04, 09:56 AM
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Wink

no crazy amounts of smoke on start up eh? no hard start?
Old 09-03-04, 10:03 AM
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Originally Posted by tomfolfd
no crazy amounts of smoke on start up eh? no hard start?
Slug in the overflow tank as nothing to do with coolant seal failures.
Old 09-03-04, 10:23 AM
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yeah Id flush out your coolant like ....NOW
Old 09-03-04, 11:28 AM
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I had the same gunk on my tank when purchased the car. I think the gunk its a convination of old, hard water, old coolant, mold and possibly tiny chunks of rubber tipical of not fushing the system regularly. I recommend to flush your system twice really good, monitor it for 1K miles and you should be just fine.
Old 09-03-04, 11:29 AM
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Yep... This weekend, it's getting flushed. I do it once a year, and it's been about a year. How oftern do you guys flush the system?
Old 09-03-04, 11:36 AM
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I took my 7 for a hour drive on the interstate pull over to the store, went to start the car and it would have a hard time starting , but couldn't get it to turn over until 1/2 hour later ,the i drove home. I don't remember if i had the coolant light on. Anyways when i got it back home i check my coolant reservoir tank i had thick black slug on the dip stick. I had the shop do a compression test back rotor was low. It ended up being the thermostat was stuck. And that i blew my coolant seal.I had to Put a new engine in. Doesn't sound good.
Old 09-03-04, 11:55 AM
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Originally Posted by silverflash2
I took my 7 for a hour drive on the interstate pull over to the store, went to start the car and it would have a hard time starting , but couldn't get it to turn over until 1/2 hour later ,the i drove home. I don't remember if i had the coolant light on. Anyways when i got it back home i check my coolant reservoir tank i had thick black slug on the dip stick. I had the shop do a compression test back rotor was low. It ended up being the thermostat was stuck. And that i blew my coolant seal.I had to Put a new engine in. Doesn't sound good.
That black slug was water mixed with oil, your car had overheated & the temp gauge is as useless as F with PMS; ofcourse.
Old 09-03-04, 03:14 PM
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the black crap on the dip stick is probably the vaseline used to hold some seals in when the motor is assembled. I wouldnt worry about it.
Old 09-03-04, 04:50 PM
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yeah i got the same ****. It smells like some **** nikalodeon used to make called "Gak" it was like a gooey putty thing. Like what was said b4, i think its just an accumulation of old hard water, old coolant and bits of rubber debris. Time for a flushy flush.
Old 10-24-04, 06:12 PM
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Originally Posted by saburo
yeah i got the same ****. It smells like some **** nikalodeon used to make called "Gak" it was like a gooey putty thing. Like what was said b4, i think its just an accumulation of old hard water, old coolant and bits of rubber debris. Time for a flushy flush.
ahahaha thats weird thats the first thing that came to mind when i smelled it... phew just did a search on this and im glad most people seem to think its not serious
Old 10-24-04, 06:31 PM
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black stuff might be from the inside of your radiator hoses (when they are new, it might be the mold release or just deteriorating rubber). its fairly normal. just check to see if you have a lot of white smoke comming out of your car.
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