Odd cooling problems.

[jabartram]

I've posted this at 2 other sites with no help, so i'm gonna try here also?
i have a strange cooling problem with my 03 3400, at idle my car runs 181* running normal speed on the freeway it run 190+/- if i accelerate to higher speeds the temp climbs to 210/215* slow back down to normal it almost instantly drops to 190*, so far i have replaced my belt, waterpump, thermostat aprox a yr ago [hypertech 180*] flushed my cooling system, running 50/50 water/waterwetter now, checked my fan operation[good], today i installed a new lower radiator hose, and checked my upper[ok], washed my rad fins best i could[i see blockage on the outside], ran at idle in my drive way got to 180*, revved ti to 3800 rpm and watched my temp rise[scanner connected also] to 207, let drop back to idle, within 5 mins it was back down to 181* revved to 3800 temp rose to 210, let off back to 182, i'm at a loss as to what to look for now, anybody else experienced this problem, or have any ideas?

[robby1870]

RE: Odd cooling problems.

I dont see the problem.

[eliteweapons]

Remember newer engines usually run at 200 degrees to 220 degrees for the catalytic converter to properly eliminate exhaust byproducts so if you are only running at 207 max you are fine.

[jabartram]

well it only started doing this a couple months ago, it was running 190* with very little fluctuation no matter how fast i was going, i havent kept the speed up to see how hot it will get. if this had been happening since i owned it, this wouldnt be bothering me, but like i said this has been occuring only recently so i'm concerned.

[eliteweapons]

I know this is a dumb question but has the temperature outside increased in your area over the last 3 months? Summer can have that affect on this. When you flushed the system did you use chemicals or just water? The only things left is either the stat is not opening fully or your water pump isn't flowing enough. The lower radiator hose can be a problem sometimes too at the water pump where the sharp 90 is. Have you changed anything in the fuel system? If it is running lean it can cause it to heat up as well? Need more info on the car. Mileage, type car, maintenance, and so on.

[bszopi]

Its normal for the cooling system to cycle like that, even with a lower temp stat, so its not a problem. Did you just happen to notice it a few months ago, so you started watching it, and its doing it all the time now? It very could have been doing it before and you just didn't notice it.

And remember, the faster you go, the more the engine is working, so the more heat it will produce. This puts more of a load on the cooling system, therefore it won't be able to keep it at such a low temp all the time. When you slow down, the engine isn't loaded as much, therefore isn't producing the same amount of heat, and thus the cooling system can respond faster.

If 215 is the highest you've gotten it, I would be far from worried. Besides, sometimes too much cooling can be just as bad as not enough cooling.

[jabartram]

I know this is a dumb question but has the temperature outside increased in your area over the last 3 months? Summer can have that affect on this. When you flushed the system did you use chemicals or just water? The only things left is either the stat is not opening fully or your water pump isn't flowing enough. The lower radiator hose can be a problem sometimes too at the water pump where the sharp 90 is. Have you changed anything in the fuel system? If it is running lean it can cause it to heat up as well? Need more info on the car. Mileage, type car, maintenance, and so on.

it an 03 Olds Alero 3400 auto, mods, flowmaster cat back, highflow converter, TOG headers, headers are fully wrapped to keep heat down, DHP pcm, Apoc C.A.I., B&M transcooler, 62mm t/b, Denso iridiums, Taylor wires. and the rest listed in my first post for the cooling system, the question about outside temp, yeah we experience heat index temps in the range of 105 to 110 degrees commonly, but it wasnt doing this last summer. i'm running autometer guages so i know the temp is within 5 degrees, compared to the pcm temp, usually when temp gets to 215 i backout of the throttle, so i dont know for sure how hot it will get?

[sil]

air in the system ?

[eliteweapons]

Did you increase the injector size or pulse to compliment the larger throttle body? And did you chemically power flush the system or just flush it with water? Do you have an exhaust gas temp gauge on your car?

[jabartram]

I have whatever DHP did when they programmed my pcm and i just water flushed the system. not exhaust temp, just and a/f guage. would the 62mm throttle body cause a problem like this? i haven't put any ported manifolds on yet?

[eliteweapons]

Did you do any mods or work on the engine between now and last summer? A chemical flush could help if there is any buildup in the system. What is your a/f gauge ratio? Does it lean out under mid to higher rpms? An ait fuel ratio gauge measures exhaust temp to tell you the fuel to air ratio in the exhaust using the temperature range for comparison. Have you checked your fuel pressure?

[torq455]

revving the engine in the driveway will cause the temp to climb. no air over the radiator, unless you have the fans come on sooner. the real test is to drive like you did when the outside temp is what it was when you were driving your car before the prob.