There is no way in the world for you to get oil in the coolant from a bad radiator as there is no oil running trough it.
It may have been the cause for an overheated engine which can cause gaskets to fail and let oil in the coolant or coolant in the oil, but the radiator alone is probably not the issue.
Dealer told me that it was the radiator and that it is not covered in the powertrain warranty so quoted me for $860 plus tax and I had to pay $133 for the diagnostic fee which they will discount if I got the repairs done.
Performance is suffering, makes clicking noises only when I put the gear in and exiting my parking lot at very slow speed.
Also right after I left the dealership it has been jolting me and stalling then kicking me forward when I accelerate or getting up in the speed limit.
So the vehicle got worse after I had them see it.
To top it off they my tire was low on air and they didn't even top it off.
I asked him how sure where they that it was the radiator and they he told me 100%.
What do you guys think ?
My friend is a mechanic, can I just buy an aftermarket radiator and have him install it, flush all the fluids and refill ?
Or is it likely that this damaged something else in the vehicle like the transmission ?
I am not that picky, I just want to get my car working and reliable again.
If I have to spend the $1000 I will, but if I can do it for - $400 I'd be much happier.
Sorry to hear about your experience with Chevy dealers. I have owned 1964 Corvair, 1967 Impala, 1971 Nova, 1977 Malibu, 2011 HHR, 2017 Spark, all purchased new, and had always received decent service from Chevy dealers. But here is a clue, I prefer taking my car to either a Buick dealer or Cadillac dealer for service when possible. Those folks seem to be more responsive, and have much better manners, and seem to have the parts needed for Chevy cars, or they can order the parts.
On that 1971 Nova, I had 60K miles on it, when engine suddenly began making horrible hammering sounds. The nearest Chevy dealer wanted to overhaul the engine for thousands of $$$. I studied the manuals, figured out what the problem most likely was, went to a Buick dealer and they repaired the bent rocker arm for 1/20 th cost estimate from the Chevy mechanic. Then I drove that car to 150k miles with no problems.
There are posters right here on this forum who have been driving their Sparks for over 100k miles without any major issues. But from what I read, those folks take good care of their cars (maintenance, recalls etc) and know a lot about cars. OldGearHead is one of them. I bought my 2017 Spark LS 5-6 months ago, and it is running like a clock, only issue I had was a creaky passenger side front door when opened. The dealer lubricated the hinges but it is still creaking a bit. I can live with it until next time when oil change will be due. And mine is metallic Splash color, and it is a very nice color.
Keep the G5 as long as it is running good. I owned this 2007 G5 for 9 years and did not have a single issue with it, although since I am retired, I do not put lots of miles on the cars. My G5 could almost spin the wheels, had much more acceleration than my 2017 Spark LS, was much heavier and stable at very high speeds, and not bothered by cross winds. Spark is light and tall, so does get more affected by cross winds.