Got another s4 (non turbo/convertable WOO) auto

Okay, right about when the thermostat should kick in (this is my first guess) it overheats. The upper radiator hose collapses and I think the flow stops. So what I think I will payday, is install a new thermostat and maybe change the fluid. The car has had a rebuild from what im told, and I think it has <50k?? and the water pump looks like crap. previous owner said it was replaced but I dont know how reliable that source is, the guy was cool and honest but told me straight up he knew nothin about cars.

car has trouble starting up (i hear thats common, not to me though) set up is still stock. (no plastic front peices or intake peices removed... yet.)

 

I'd be checking the Cooling system..#1 would be the Thermostat..to me it Sounds like it is in incorrectly..in Reverse...and a compression check will tell you if the Engine has a coolant Seal gone..compression check while you have the Rad cap off..if you start the engine,the compression that is In the Engine will create air,and that will be noticeable when you Crank it,and then Look at the Comp Tester.the tester will go down and not hold a Constant reading,and also Bubbles will appear in the Cooling system..IF it is Real bad,then the coolant Will ERUPT out of the Cooling system opening(either rad cap or thermostat cap opening)...be careful and good luck.

 

if u buy a new stat order one directly from mazda. dont just go to advance auto or napa. i bought a stant thrermostat from advance 2 times, and they both stuck, i spend twice as much on an genuine mazda thermostat and NEVER had an issue

 

as for the hard starting try replacing the plugs, and wires and go from there, my last one flooded alot, and again, dont just buy the cheapest plugs u can find, they foul in a month or so.

 

ngk all the way baby. my vert is running like a champ. (well now i have to add coolent in that every other day...)