Brown sludge in my coolant
 

I have a 1999 camaro with the 3.8 v6 with 122,000 miles and it runs great! But I'm just taking it out of storage and checking everything over and I noticed that the coolant is brown sludge. The car never overheats and runs awesome but I want to figure out this problem... Anybody know what is causing this? I have read online it might be my trans cooler lines leaking in the radiator, or it's a blown head gasket and it's oil leaking in there. It doesn't smoke white or anything. I need help

Re: Brown sludge in my coolant
 

If the trans cooler was leaking into the radiator, it would be red and floating on top for the most part. I have had this problem before - buy and install new radiator. Do not drive until that is done because you can get coolant into the transmission which is not good.

A blown head gasket will sometimes let water into the oil. Is the oil normal looking? A compression check would reveal more info.

I would start off my flushing the coolant system.

Another thought, the previous owner may have had a minor leak and put stop leak in there. It works but makes the coolant look bad.

Re: Brown sludge in my coolant
 

Ok thanks! I will flush the coolant system tonight. The oil looks fine and there is no water in it. I was hoping it wasn't the head gasket.

Where can I get it a compression test? Dealership?

Re: Brown sludge in my coolant
 

any shop can do a compression check, and there are ways to do it at home aswell

Re: Brown sludge in my coolant
 

advance auto has a tool rental program, usually free. pick up a compression checker there.

Re: Brown sludge in my coolant
 

Ok I'll have to get it checked. Thanks for the help!

Re: Brown sludge in my coolant
 

its just the dex-cool. mine did the same thing, after sitting for about a month... i just flushed my radiator and refilled with 50/50 dexcool/water.

Re: Brown sludge in my coolant
 

Yup, it's the DexCool.

If it's old, it's time to change it out anyways. But if it's fairly new, that means there is a leak somewhere that is allowing air into the system. DexCool is very sensitive in that respect and it turns DexCool into the brown sludge. Check your reservoir dipstick, it's likely gunked up too.

If this is the case, you'll need to try to find the culprit and then flush and fill the radiator a few times until it comes out clear and then refill.

Re: Brown sludge in my coolant
 

Probably have a slight lower intake manifold gasket leak too.

Re: Brown sludge in my coolant
 

i would say having a little sludge on the dipstick is probaby normal if the coolant is a few years old, I religously have my coolent changed before 5 years.