Toyota Repair: Toyota T100 105000 miles, blown head gasket, radiator overflow tank

Question
QUESTION: My T100 just started to chug ( bounce like it's not firing on all cylinders) upon initial cold start up.  If I rev it up I see some white/gray smoke from the tailpipe.  After about 20-30 seconds it starts to run normal with no smoke.  If I stop somewhere and the engine is still hot it doesn't do it.  Only happens on cold start currently - no matter what the outside temp.  Could it be a dirty fuel,  air filter,  or something with the choke?
Thank you

ANSWER: The smoke is water condensed in the exhaust.  It is of no concern.  The chugging may be due to your cold start injector not working properly (loose electrical connection, blown fuse, plugged injector, etc.)
Check out those things first.

Hope this helps.
Vince

---------- FOLLOW-UP ----------

QUESTION: It doesn't happen everytime.  It didn't happen after work,  but last night when we pulled my truck in the driveway it happened again,  and then this morning it was ok again. Does that seem like a plugged injector?  Would injector cleaner that you add in the tank help?  It could just be a coincidence,  but it seemed to start after I stopped and put gas in the truck at a speedway by my house.
Thanks

ANSWER: AH!!!
Water in the gas.  Buy some STP to dry out the water in your gas tank.
Don't buy gas at that Speedway again.  Their fuel fill location might be allowing water to enter.

Vince

---------- FOLLOW-UP ----------

QUESTION: I had Toyota replace my timing belt and exhaust.  After they replaced my exhaust within days my check engine light went on.  I needed both O2 sensors, just today I noticed that my radiator overflow tank looked like it had oil in it. My radiator also looks that way, am I looking at a blown head gasket now,  or could Toyota's service dept. screwed something up when the timing belt was replaced.  The truck has 105000 miles and has never over heated, or had any problems other than tires, brakes, and exhaust.  Do you have any ideas on what I can do or how much this costs to fix? Are there any additives I can try before spending lots of money on an engine tear down?
Thanks again
Thank you

Answer
Anytime a timing belt is changed, the water pump should be changed also, due to the same things have to be removed to get to the timing belt as well as the water pump.  Something might of happened during this evolution.  Ask the dealer to explain the work procedure he used to change your timing belt.  Ask if he changed the water pump.  Did he change any gaskets?  Did he charge you for these gaskets?  Check your work order to see what parts are listed.
You may want to do a compression check on your cylinders to see if you are losing pressure in one or more cylinders.  This may indicate a blown head gasket, warped head, cracked block, etc.

Vince