Hello Scotty,
I have a 2005 Scion TC with 200,000 miles on it. I recently noticed that there was some smoke coming out of the engine compartment when I was stopped at a light. When I came back and popped the hood, I saw that the heat shield had oil over it and that was causing the smoke. There appears to be oil coming out of the valve cover. I assume it’s a blown head gasket. Will a quick deal through the radiator work or should I replace the gasket? Also my coolant has turned brown, which tells me I am way past the date I need to replace it, but I don’t see any indication of overheating. Is there a reason for that?
Don't confuse a leaking valve cover with a leaking head gasket. On most engines the valve cover is trivial to replace and you should do so if yours is indeed leaking.
Coolant turns brown over time as anti-corrosion additives wear out and the coolant picks up impurities from inside the engine. You should flush out the cooling system ASAP and put in fresh coolant.
My bad. I was indeed talking about the gasket that goes under the valve cover like you point out.
As for the coolant flush, I was at Walmart looking for coolants and they had Prestone 50/50 diluted anti-freeze mix and a concentrate. The description says that for cases where the coolant system is being flushed, use the concentrate (mixed with water). I am a little confused here because if we add in water to the concentrate to make it a 50/50 mix, how is it any different from the ready to use 50/50 diluted mix and how does it benefit the flush and drain process?
Typically what you want to do when flushing out the cooling system is get out all the liquid you possibly can out and put in half the system capacity with antifreeze concentrate, then fill the rest up with distilled water. I just did this on my old Jeep. (It's also cheaper to make your own 50/50 with distilled water than buying premix. I never buy the premix.)
I usually flush it out with plain water, blow out the excess with compressed air and refill and burp the cooling system with the pre-mixed 50/50 coolant.
Yep, that's the idea, I'm just cheap and do the 50/50 mix myself.
It's not a head gasket. Just replace the valve cover gasket.
From top to bottom, here are the parts of the engine. I always thought the head gasket was the very top of the engine, but it is not. Heck I don’t even know the proper names, just the general location of each.
Valve Cover
Valve Cover Gasket
Head Cover
Head Cover Gasket
Cylinder Block
Oil Pan
There are many more parts than that
and the configurations can be really engine dependent ...
pushrod or OHC
in-line, V, or boxer shape
various intake types,
etc...
MMJ has a more detailed explanation. Mine just covers a few which I personally got confused with each other.
Thanks Kaizen and MMJ! 🙂