I will start with a little back history. I have a 92 miata as my DD. It has 319k on it. I picked it up at 303k. When I got it I did timing belt, water pump, head gasket, and replaced the radiator and all the coolant hoses.

It has been driving fine for the past 1.5 years fine. When I got home from the Mitty yesterday after driving 5 hours/300miles my over flow tank was gurgling so I popped the hood. I pulled out the over flow tube and this is what I saw.


WTF causes that. My whole overflow tank is covered in it. The car has not over heated at all. It just looks disgusting. I am planning on continuing driving the car since it has not seemed to affect cooling at all.

So my options as I see them are.
1. Ignore and just keep driving until I actually start over heating.
2. Replace overflow tank with a clean one.
3. Replace overflow and radiator.
4. Pull motor and swap in 1.8 and new overflow and radiator.

The future plans for the car have always been to drop in one sort of 1.8, although I was not planning on that until end of summer or fall. Other then that I want to hit 500k on the car.

 

dude, someone put poo in your overflow.

what does the fluid in the radiator look like?

if the fluid in rad looks okay, I'd pull overflow and clean, then return and hope that your prankster confesses.

 

I just took a look at my radiator and it looks full of the same crap. So I guess replacing the overflow tank and radiator will be in my very near future. I am actually surprised that I have not had any over heating issues.

So what would cause this?

 

I"ve had the same buildup of crap in my overflow and radiator and all the radiator hoses, not sure what causes that.

 

coolant + oil makes a creamy looking substance, so I dunno.

 

dirty rusty water coolant aids **** poop

 

Your HG could be leaking into a coolant passage. Flush the system and see how long it takes to get nasty like that again.
Just be mindful and check your coolant frequently. If it takes a while to get nasty and you see no other signs of HG failure, I'd just let it be.

 

Will do, I will flush the system in the next couple of days. Then watch it.

I might be swapping in my spare 1.8 sooner then expected.

 

I think your car got bum reamed by a POZ

 

Duck butter?

 

I've heard that if you had Dexcool in it and don't change it for a long time then it will turn into brown sludge.

Or if you ran any kind of Head Gasket repair or anything like that through it at any time it'll make brown sludge.

Do a complete flush and fill it with water for a couple months... if everything seems ok...drain and fill with proper green mixed coolant.

 

I do no know what Dexcool is so I am doubting I have it in my system.

Never ran any head gasket repair stuff, I did change the HG back in Dec/Jan 2009/2010. IDK if the previous owner ever used any, and I really don't remember what the stock radiator looked like.

I will flush and just watch the system.

 

I talked to Steve@Panic Motorsports today about a new radiator and overflow tank. I asked him what he thinks would cause the build up. His response was that if I was not using distilled water it could easily do it. I being lazy am not using distilled water in either car. So I will be flushing the system this week and putting in new coolant and distilled water.

The water in my 94 was also browninsh. So I will be switching it to distilled water and water wetter also.

 

The sediment in normal water could do some funky **** but I've never seen it that severe or that quick. My stepdad was a moron, but built some quick cars, and he always used hose water and never got any funky ****.

My mother never maintained a car at all... in any capacity... and if a car of her's ever got any water I promise you it was not distilled. That is seriously some fucked up repugnant ****.

I like the dexcool theory. Dexcool is the orange stuff GM decided to use when they felt normal coolant wasn't good enough. It sucks, and it can gel and will do so if mixed with standard coolant. Various German coolants behave this way also, since German car companies enjoy both making our lives more difficult, and engineering new solutions to problems that didn't exist and end up working worse than the conventional method.

spark notes: iffy on distilled water, you sure you didn't use odd coolant? where's my VVT?