Doc16743

New user here and thanks for providing this forum!

The 4.2 in my 2007 Trailblazer just blew and needs to be replaced. I see many opinions in searching about direct replacement, so this is a simple question (I hope!)

What year(s) of the 4.2 are a direct replacement for my 2007? I keep reading nightmares people have had due to different crankshafts and harnesses. What limitations do I have to put on my search for a used replacement??

Many thanks!
Dave

vipergg22

Think they made some changes in the 2007 year so probably 2007-2009 are your best bets .

tech2

in addition: the eighth character in the vin is the engine code....make sure the donar vehicle code is the same as yours

Doc16743

Thanks for the information! I finally was able to talk to a Chevy tech and was told that for my 2007 TB that 2006 and 2007 were the only years that are directly compatible. And, for once, my luck held. Found a 2007 4.2 nearby, so my mechanic will probably start the swap on Monday.

Just out of curiosity, I got an estimate from my local Chevy dealer for the engine swap. They quoted $1870, plus any parts they might need - not including the price of the engine! Made me glad I have a good mechanic!!

Thanks Again
Dave