My truck starts really rough at least 50% of the time. Sounds like it's hitting on 4 cylinders. I can kill it and restart with some throttle and it'll be fine. If I just let it run it'll idle rough like that for quite a while before it clears. Once it clears it it'll run fine. No smoke, no white exhaust, coolant level doesn't appear to be dropping.

Does this sound like a HG or something else?

Other than the rough starts, the truck runs strong. Good fuel ecomony, etc.

Thanks,
-john

 

If the head gasket were leaking enough to cause a rough idle on start up, it would be loosing coolant. And really it should be running hot as well. because combustion gases would be aeriating the coolant.

It might be loading up with too much fuel. This can also be due to not enough air. like if the auxillary air valve is not opening. How fast does it idle when it is cold? (after you clear it out)

 

idles about 1000 cold. I found references to the aux air valve in a few other threads. I'll check that out? Anything else to look at?

Btw... before I got worried about the HG, I was thinking too much fuel. What about a bad injector?

Thanks!
-john