4.7 Engine overheating at high speeds

[Slow4.7]

Hello everyone, I'm new here. I'm posting this because I'm having a problem with my engine overheating at high speeds, for example, if i raise my truck to 90+ mph it slowly starts heating. I don't know whats the cause, the mods I've done to the motor are: CAI, Power wire, Superchips 3715 Max microtuner, borla exhaust, no cats, magnaflow Y pipe, and TMR delete (felt no difference btw). The coolant is at a normal level so I dont know what could be causing the problem. Anu input is valuable, thanks in advance

 

[toofart]

Bad thermostat, bad water pump is where I'd start. Bad pressure cap, hose collapsing, blocked water passage, bad gauge, running too rich would be next.

 

[Slow4.7]

Bad thermostat, bad water pump is where I'd start. Bad pressure cap, hose collapsing, blocked water passage, bad gauge, running too rich would be next.

Could it also be a bad sensor? Because sometimes when i turn off my engine and turn it back on the needle goes past the normal level and then comes back down after a while

Thermostat should be good, its less than a year old, i also replaced the radiator at the same time

 

[toofart]

Yeah that's what I meant by bad gauge. If you have an infrared thermometer you could check the top and bottom hoses from the rad.

 

[Slow4.7]

Yeah that's what I meant by bad gauge. If you have an infrared thermometer you could check the top and bottom hoses from the rad.

Oh ok, don't know what kind of thermometer it has, its a 2002 truck, but I'll investigate, thank you for your help

 

[toofart]

I meant, if you know someone who has an infrared thermometer, you can gram various temps like the upper and lower rad hose to determine if coolant is flowing, etc

 

[Papa Bear]

I had pretty much the same problem with my 2004 Ram..it had the 4.7 in it as well and it turned out to be the coolant that was put in at the factory ..it had clogged up the radiator..

 

[Slow4.7]

I had pretty much the same problem with my 2004 Ram..it had the 4.7 in it as well and it turned out to be the coolant that was put in at the factory ..it had clogged up the radiator..

Ohhh ok, sorry, i dont know much about engines

 

[NHDuckHunter8003]

Not sure about the baby 8's but I know the hemis cant have the green coolant in it. My truck had that stuff in it when I changed my tsat but I'm not sure if my truck had those symptoms. When I was doing 90+ I wasn't looking at my temps I was watching for cops...

 

[Slow4.7]

Not sure about the baby 8's but I know the hemis cant have the green coolant in it. My truck had that stuff in it when I changed my tsat but I'm not sure if my truck had those symptoms. When I was doing 90+ I wasn't looking at my temps I was watching for cops...

I dont remember the coolant color but the mechanic who changed my radiator put new coolant in it, and yes I keep a look out for cops too but I also dont want to ruin my engine again, so i keep an eye on all gages and warning lights

 

[aquinas]

I have the same problem when climbing hills for a long time. It is always at highway speed while under load. Idling and around town driving is no problem. I plan to replace the radiator with a 2-row for the 5.7 and see if it helps along with replacing the thermostat and possibly the water pump.

 

[WalterG]

I dont remember the coolant color but the mechanic who changed my radiator put new coolant in it, and yes I keep a look out for cops too but I also dont want to ruin my engine again, so i keep an eye on all gages and warning lights

Not that I am an expert on this, but what do you mean by "ruin my engine again"

I have the same truck, 02, 4.7, and although I haven't run at those speeds for long periods of time, I haven't seen jumps in temp that wouldn't be normal considering the increase in RPM by running that fast.

On another note, you said the tstat is fairly new, less than a year. That doesn't necessarily mean its OK. I have known tstats to be bad out of the box. It is possible to have it go bad in a short time, not likely, but possible.

WalterG