I know that this has been discussed before but I think I have a differant problem with my car running hot....So here we go. I already checked the radiator for dirt bags all that stuff and hosed it down and cleaned it...I replaced my water pump and thermostat with the stock pump and stat brand new and I already replaced the antifreeze holding tank.....So here is what happens when im stopped with the car running the temp go's up to 240 degrees when I am not moving. When I give it gas and get the rpms up to about 2000 the temp comes right down to 200 degres when I am not moving.

Could someone please help

 

240? time to clean out your radiator. I would bet there is lots of dirt, sand, grass and dead micky D's bag up there.

Plus check your t-stat settings and may be how your water pump is working.

 

I said that I cleaned the radiator replaced the water pump thermostat and antefeeze tank already........Still getting high temps standing still at idle....When I give it throttle while standing still the temp comes right down???????????

 

List your mods.
Do you have a underdrive pulley?

 

clean the radiator? It needs more than a squirt with hose from above?

 

Something is not working right.

car should get no where near 210 let alone 240 just sitting there.

Fans not coming on? Coolant not pumping though? a little throttle may get the coolant to flow better

When are your fans coming on or set for?

 

There is no mods on the car....And I never changed the fan settings....Could it be the radiator itself......I will need to check the fans to see if there coming on.

 

Do you have enough coolant in?

I noticed my Silvardos coolant temps were a bit on the high side this winter when I started out. Then they dropped.

Turns out it was low on coolant. Filled it up to where it should be and everything is A OK

 

Your temps should get up to just over 230 degrees, that is when your fans will kick in and bring the temps back down to about 200. Then the fans shutoff and the temps should rise again to about 230. Rinse and repeat.

I would check the fanbelt to ensure its turning the water pump fast enough. Maybe you could get a smaller diameter water pump pulley?

 

I will have to check it again and see if it is low.....But I dont think so.....Could there be a problem with the passes in the radiator. Or maybe air in the system???????????????????

 

I agree with most everyone here. Make sure you are full up on coolant and that there isn't any hidden airpockets in there. Make sure the fans are running. Was there a time that the radiator was open? If so, you might need to replace the coolant if you didn't already. Speaking of that, it might be wise to consider flushing the system. Do you smell any coolant? Steam coming out of the exhaust? Any traces of coolant in the oil?
As already suggested and you responded that you washed everything down in there and specifically the HVAC condensor. Hopefully you found a wand of some type with a curve and washed the rocks out of it from between the radiator and condensor and back out towards the front. I have to do this about once a year. Back to the fans, turn on the AC and at least one of the two fans should be running right away.

 

No coolant in the oil and no smoke out the exhaust....I red on another thread that the passes on the radiator get blocked sometimes......That the dexcool does not last the so called 100000 miles or the 5 years it says it does and since I am not the orig owner im not sure how often it was flushed but I did change the antifreeze when I installed the water pump and new stat.......

 

Actually mine will do this too, but I live in Southern New Mexico and on 100 plus days in town mine will reach 220-240 without any problem. Comes down once get moving. My fans work fine, new antifreeze every two years. It is just the way it is. However, I cannot see getting that hot right now in Illinois.

Were you running it real hard and then got into town/stop and go traffic?

 

No I wasent running it hard.....And yes it is only like 32 degrees here right now......There has been some other threads about this very problem....Some pepole say its electrical some pepole say it is the raidiator......Just thought I would bring it up again to see if someone could help.....

 

Ok I ran the car today and the temps are at about 200 degrees at 65 mph when it was 40 degrees outside and when im stopped they shoot up to the 230 degree range.....Now keep in mind I have a stock stat so is that why it is running at around 200 at all times.....My point is that I think I might have a problem with the fans since at idle the temp shoots up to 230 to 240 with no air going across the radiator....But I cant seem to understand why when im parked with the engine running the temps shoot up but when I give it some gas while parked the temps start coming down around 2000 rpm......Does this sound like I have more than one problem like.....1. Fans not coming on and 2. Air in the system or blockage inside the radiator that is why the temp drops when there is more flow when it is at a higher rpm at a stand still when the water pump is turning faster.

 

So if you are sitting at a stop, and the engine temp rises to 230-240, and all you have to do to cool the engine is raise the revs to 2000 ????

If that's true, your fans are working.

You are either low on coolant, or you have a pressure/circulation problem with your coolant.

Your coolant should be a 50/50 mix of Dexcool and fresh water. It should be, when the engine is cold, above the MIN mark in the coolant reservoir.

If the above is true, start your engine and let idle. Open the hood of the car.

As the engine warms to about 200 degrees check the radiator hose temperatures. CAUTION - keep clear of the fans and other moving parts. The upper hose should feel hot, and so should the lower hose. If the lower hose stays cool even as the engine temperature goes past the point where the fans turn on, you have a circulation problem, either a blocked radiator or hose ... or a bad water pump.

Check that the serpentine belt is not slipping as it drives the water pump. Also check that the coolant reservoir cap is holding pressure (listen for hissing sounds around the cap) .... turn off engine to hear more clearly if need be. DO NOT open cap when coolant is hot.

Post what you find and we can go from there.

 

Remember that the radiator sits behind the ac condenser....

 

It really sounds like your fan's aren't running. If you have the HVAC turned on, at least one fan should be on. If no fans are running with the HVAC on, look at the ground pack on top of the right frame rail just behind the right hood mount. The fan grounds are there. Of course, look at the fuses and so on. There are two relays for sure that run the fans if memory serves me right and they are located in the engine fuse box. If you remove the cover from the relays, you can simulate the computer turning them on by manually pushing the contactor, the fan should come on.

 

Assuming his description is accurate ..... if his fans weren't working, sitting at a stop and raising the engine RPM to 2000 would make the car overheat FASTER ... but the OP says the temp comes DOWN .... his fans are working ... he's either not circulating coolant or he's not got enough coolant in the car ....

 

You could indeed be correct.