So within the last few days I’ve noticed my car from a cold start will get to roughly 220ish really fast. Yes I’m aware that it is a normal temp but it seems to get there within 1-2 minutes. Basically from when I turn the car on and cruise out of my apartment complex at a slow speed. It doesn't overheat and once I get up to speed it cools back down to 200 which I am aware is also normal. I haven’t seemed to have lost coolant and there’s no white smoke coming out my exhaust so I know it isn’t a leak or a blown head gasket. I also have pretty fresh coolant in the car. Does anyone know what could cause the car to randomly heat up faster than normal? So far it hasn’t caused any issues but I want to make sure there is not a issue.

 

It's possible the cooling fans are not coming on, they are turned off once the car exceeds 35mph, but if the car is just idling or in slow traffic they are programed to turn on at about 226 degrees in low speed, if the temperature increases much more they go into high speed operation.

 

well the car hasn’t gone over 225 yet and I’ve let it idle at 225 for about 5 minutes, it would go down a little then raise back up to 225 but never over. So I am assuming they are turning on, I’ll check again tomorrow to see if I can see them spinning. My car is also tuned so fans may come one a little earlier now.

 

I don't believe you have a cooling problem, but you might check for junk collected between the ac condenser and radiator, c5 corvettes are bottom feeders and they suck up all kinds of debris.

 

Evaluate how the engine behaves at idle and stationary and report back.

 

Before going crazy, burp the cooling system to make sure that there is no air in it!

 

good news, after the last few days the hottest the car has gotten was 230, Bad news checked my coolant as I was doing my A/C recharge seen the coolant was a bit low. Looked under the reservoir and seen a pin hole leak in the outlet hose that goes to the water pump. Order the hose topped off the coolant and car hasn’t gotten hotter than 208 today.

 

That's what I was leaning towards, there was a leak in the system.

 

yeah, it was just leaking so slowly I didn’t catch it at first but now I know for next time.

 

You can't just change the hose and top of the reservoir. You have to get the air out. Follow the service manual procedure for draining/filling.

 

He may be OK without purging. BUT, I do agree with you. It's usually best to follow established procedures. OP, the best way to do this is to elevate the front tires a couple of feet in the air while the rear tires are on the ground. Use a floor jack or if you have a hilly yard, whatever. Remove the recovery/expansion tank cap (ONLY WHEN COLD!!). Start the car and add the coolant. HOWEVER, and this is a "while you're in there" thing, this would be a great time to flush the old coolant out and add all new antifreeze mixed 50/50 with either deionized or distilled water. If your coolant is fairly new, just slowly add a fresh mix of 50/50 coolant......

 

What is the purpose of raising the front end?

 

You do that with a car that has a Radiator Cap, gets the air to the very top of the system and out.

This case tho the Expansion Tank is higher than the Radiator so to jack the front of the car up you'll be trapping air. Just my thought.

 

Exactly right.

 

I've never had an issue bleeding air by elevating the front end. Always worked for me, and IIRC, my factory service manual recommends elevating the front end... ..

 

I will add that I have squeezed the upper radiator hose and heater hoses to help squeeze some of the air out. I've also left the radiator cap off and filled the radiator itself. All I know is what I've done works for me. On the Mustang dyno my coolant never went over 185° during 3 WOT tune adjustments......

 

I'll preface by saying, I'm in no way trying to give you a hard time here.....just keeping it straight for anyone that uses the forum for their service manual.

IIRC, you have a 2000. Your 2000 service manual does not tell you to elevate the front end.....rather...it specifically tells you to park the vehicle on a flat level surface.

Now....here is what may add some confusion in the "Draining and Filling Cooling System" procedure in the service manual over the years.

From 97-2000: the service manual tells you to park on a level surface, relieve pressure from the surge tank, and then drain the radiator, close the draincock, and proceed with the fill...and air purge. GM most likely realized that if you do not raise the vehicle, is damn near impossible to reach the draincock, and not doing so would also not allow a container to catch the coolant being drained.

From 2001-2002: the service manual tells you to park on a level surface, relieve pressure from the surge tank, raise the vehicle, drain the radiator into a drain pan, close the draincock, and proceed with the fill...and air purge. This time, GM forgot to include lowering the vehicle.

,,,,and then it gets a little more weird.....

From 2003-2004: GM removed the statement "park on a level surface"....and they start with raise the vehicle, drain the radiator into a drain pan, lower the vehicle, remove pressure cap, raise the vehicle, close the draincock, lower the vehicle, and proceed with the fill...and air purge. This is a real gem, because they have you open the draincock on a system that could have residual pressure. WTF?

In any case, the coolant system should be drained/filled and purged of air on a level surface(or level lift)...as that is how the system is designed. Raising the front end puts air bubbles when they cannot get out. While this may be a small amount, and have little effect on overall performace(if any), it's just not good practice.

 

You must have a different C5 than we all do. No Radiator Cap here..

 

Damn, Merv. I could swear it had a cap!! You're obviously right. I get a pass though because my car is in another state!!That does tell you that I have no issues with my method, though. Yes, I was thinking of another car from the past!!! But my method does work, even with no radiator cap!!! Radiator cap... LMAO!!

 

Oh I've done it with stuff that has a Radiator Cap, I have the little Funnel Kit that works great to hold the coolant when it expands before the T-stat opens. That Kit is nice to have, bled many cars with it.