I have only used block sealant twice and both times it clogged my heater core.

Hope previous owner didn't use block sealant and clog up the heater core. . . .looks like I need to flush it or replace.

Just to clarify this, the Alumaseal that I recommended is not a "Block Sealant". It consists of tiny flakes of aluminum, opposed to the big chunks of gunk you find in block sealants.

You are not required to drain or flush the system after use, or clean the system before use. It is compatible with coolants, and can be ran in the system full time.

After I used it a couple of years ago, I just left it in there as a preventive measure. I have never had an issue with my heater core, and believe me, living in Michigan I would have realized if it had. :)

But the thing is after my car has idled up, the car runs fine.

I think you dont have aynthing to worry about...

It could be that you are leaking coolant into the "combustion chambers" after shutting her down. Or maybe an injector is leaking... Either issue could cause it to run rough until it cleans itself out. :)

im having this issue as well....if it even is an issue. it really only happens in the morning after its been in the garage all night.

after work or during lunch when i start it up it hardly does it at all so im going to assume its just condensation.

as for a smell, there is nothing irregular about it. smells like normal exhaust to me.

yea, sort of annoying and seems unhealthy...

With the heater core problem, my AC doesn't work. I haven't looked into it, but any help?

Could my start trouble be turbo related? Maybe a bad seal, and after the engine is warmed up the gasket could possibly seal it?