2013 Mazda cx9 camshaft and crank bolt correlation issues?

I have a 2013 cx9 touring 120,000 miles. I bought it 4
months ago and it was running great until about 2 weeks
ago or 3 weeks ago I went for a oil change and they told me
I needed to replace the radiator cuz it was cool it all over
the engine block so I replaced the radiator the car was
running great. About 8 9 days ago my check engine light
came on so I went to the mechanic he put it on the scanner
and it said camshaft and crank bolt correlation . So I drove
it for about a week and it was still driving really good and
then all of a sudden the check engine light went off. I drive
for another 3 days and I noticed my fuel mileage was
getting really bad. And it over heated. So I pop the hood and
the coolent resavore was bone dry. I look under the
passenger side of the car and all the coolent is all over the
underside of the car where the resavore is. I replaced the
coolent and drive home. It held great. But there's a clicking
or rattling sound when i start the car and it's running in
drive and idle.. also when I replace the radiator I did all the
hoses too so a hose didn't break this time so I'm wondering
what could it be I also checked the oil and the oil looks fine  
so I don't think the coolent and oil are mixing.. I'm thinking
water pump? Or stretched timing chain? Anyone else have
this issue? Also when I found out I needed a radiator the
mechanic said there was coolant all over the engine block. I
don't know if that makes a difference but if anyone can help
please do!! Attached is a pic of the underside of the car
where the resavore is. It's all wet..