64MonGooSe64

Basically when im driving at 55+ mph temps are cool around 195-200
when driving at like 35-45 mph its moves around 200-210
In really slow stop and go traffic it climbs to about 210-220

But once the car is at a complete stop just idleing away it will climb roughly 2 degrees for every 15 seconds until it gets up to around 235-240 and i shut it off.

This is all based on driving around in 96 degree temps
with IAT temp of 90 at speed and 122 at idle

Ive tried checking fans, and i can tell one side is working but im unsure of the other side, fuses might be an issue but i cant tell by sight because they are incased fuses. Water pump looks healthly and there didnt seem to be an airlock in the system but i might be wrong. full on coolant. and the front of my radator seemed to be clean with no debris.


Anyone ever encounter this problem?

bboyferal

iTrader: (9)

The front having debris isn't a problem for you anyway since you are overheating only at a stop. I'm assuming stock fans here, and I'd say fans look like the most likely problem so you really need to check that both pullers are functioning correctly maybe in your garage or driveway. Let it run, turn on the AC and the fans should both be on and both should also be able to switch to high speed. They will be blowing on your hand pretty hard at that point and you can see them easily taking a peek under without the car being lifted.

If one is not working switch the Fan #1 and Fan #2 fuse... If the fan not working starts to but the other stops, then you have a fuse issue. Go buy one.

If the same fan still won't work, it's the fan... Check the wiring, but you may just need a new set of fans.

1 FMF

iTrader: (1)

for the most part those numbers sound normal,
but it sounds like a classic case of a stuck thermostat,
the stat is stuck at an open point of normal highway operation so under those conditions no problem, but when at idle when the fans don't kick on till 226F you heat up to that, then the fans come on but the stat doesn't open more and your temp climbs.

LS6427

iTrader: (2)

Well, you said you're not sure if one of the fans is working....if its not you found your problem. Make sure they are BOTH working on BOTH low and high settings....and that they always come on and off together. One will not work without the other, unless there's a problem.

Fans are what keeps you cool at low speeds, stop-and-go driving, and when sitting still.

Check your fans. Its easy. Go for a drive, when you get up to 220-230, pull over, pop the hood, leave the engine running with the A/C "on"........CAREFULLY put your hand in front of each fan, they should both be running on high at that point.

.

64MonGooSe64

Did a few basic checks at work before i was able to read any of these.

Im only able to feel the one of the fans because the other one is tucked up under to many moving parts and i dont feel like getting my hand ripped off.

I felt one of my fans and it was blowing a storm so im almost solid that the high speed is working, and i also swaped the fuses and it continued to work... so worst case so far is the other fan that i have been unable to check is actually bad.. but thats all it could be at this point.

My fans are also tuned to come on at low at 190, and high speed at 195

64MonGooSe64

So i checked the fans tonight and looks like both fans work on the low setting, or atleast sometimes they do. but once they go into high setting one stays on and one turns off... i dont understand why one would turn off.

FirstYrLS1Z

iTrader: (4)

relay(s),there are 3 with an unusual circuit thru the 3 of them.

64MonGooSe64

ive checked all three relays and they all seem to work. i really think that the one fan is meant to turn of which is a horrible design cause now my car over heats when at a stop. the 2nd fan isnt wired into the high setting loop so once the high setting loops is enabled in the pcm, the low setting loop is turned off preventing the 2nd fan from running at all.

FirstYrLS1Z

iTrader: (4)

Excerpt from 1998 GM F Platform service manual Volume 3 of 3 Page 1610

"The cooling fan system in this vehicle provides for two separate modes of operation. These are the low speed fan and the high speed fan operating modes. The low speed mode operates both fans at half speed by using a series circuit configuration. The high speed mode operates both fans at full speed by using a parallel circuit configuration. These two operating modes are accomplished using 3 fan control relays."