So I just did an engine swap for the 350 crate engine from GM in my 99. I have compleated the swap, except now I can not get it to stop over heating. I have replaced the rad, thermostat, and the water pump and yet it still overheating. It will warm up like normal and then just continue climing up to 250+ if left on too long. This is while at an idle. Any ideas as to what might be causing this?
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99 tahoe overheating...
- Thread starter wade98030
- Start date
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Got the belt on right? Flat side of the belt against the fan pulley if the pulley is smooth too, if the pully has groves then it gets the ribbed side, check the routing diagram on the core support to make for shure......
Sorry it took so long to respond, I have been working all weekend. Yes the hose gets hot. The air is all burped out as well. I tried two new stats and also tested both with boiling water. They opened as they should. Pump is brand new, and internal was checked just to make sure there was no cracks or blockages just to make sure. I also pulled the stat out and ran it without just to make sure everything is flowing proper. It ran around 110 without the stat in constant after a 3 mile drive. Obviously I dont want to be driving around without the thermostat in though, as its not very efficient. All of the big cooling system parts are new. The only thing that was dif about that parts that I replaced was that my new radiator is bigger than the one I pulled out. It is supposed to be a stock replacement though. I am not sure if that would have any effect on it though.
oaleystormakleyguyh1
Full Access Member
bigger radiator would be better.......go to local autoparts store and get a belt diagram, cause if its wrong u might be turning the waterpump backwards.......my two cents
Just tried that yesterday. I have been driving it short distances today and it gets around 210 to 220 still. That is while driving it nice and easy. So its at least helped a little, but No where near where it should be for everything being new.
Fan clutch?
Working as intended. Its driving me nuts, it just doesnt make sense.
tonymac617
Full Access Member
What about the inlet and outlet of the hoses to the heater core? Are those in the right way? They could have been swapped??
What about the inlet and outlet of the hoses to the heater core? Are those in the right way? They could have been swapped??
Double checked the pictures from before and they are running in the proper slots.
oaleystormakleyguyh1
Full Access Member
yea i agree fan clutch is only other thing........turn hoe off grab fan and try to turn by hand,it should be stiff but not hard, if it is really easy, try to get a new one
ok first off, you swapped your engine for a used or crate engine? You thermostat is what tempature rating? are you using plain old water or antifreeze? did you replce the sensor that goes to the block to your temp guage? if you swappedd in a used engine you need to do a flush. Buy the prestone flush and fallow the instruction. Then buy a 170 degrees thermostat not the 195. Some places will not carry the 170 so you might have to shop around. After all this put dexcool with distilled water. Some people say not to run dexcool, but I have had no problems I run it with the same setup I am telling you to run. I live in a place that sees 110+ degress in summer with the a/c on and I only get up to 170 on my temp guage.
ok first off, you swapped your engine for a used or crate engine? You thermostat is what tempature rating? are you using plain old water or antifreeze? did you replce the sensor that goes to the block to your temp guage? if you swappedd in a used engine you need to do a flush. Buy the prestone flush and fallow the instruction. Then buy a 170 degrees thermostat not the 195. Some places will not carry the 170 so you might have to shop around. After all this put dexcool with distilled water. Some people say not to run dexcool, but I have had no problems I run it with the same setup I am telling you to run. I live in a place that sees 110+ degress in summer with the a/c on and I only get up to 170 on my temp guage.
Sorry for letting the thread die down. School started back up and I have been working less than desirable hours to make up for it.
It is a brand new crate engine. I was using the standard 195 stat, but just recently switched down to the 180 to see if that would help compensate with whatever this issue is that I am having. This is running a water anti freeze mix. Brand new temp sensor was installed, and the temp was checked by the computer just to make sure they were both reading out the same. Putting in the 180 seems to have helped. I am running at almost 210 exactly for my normal running temp with small fluctuations that are to be expected from the opening and closing. This still seems a little warm but much better than what it was before.
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I still recomend you run the 170 stat. I also recomend you run dex-cool. I know many use the green stuff, but original stuff in my opinion works best. Also have you tried changing out your fan clutch? Other then that you might have a engine issue. crate engine like GM factory engine? Or a rebuilt engine from a private party? You might have a block issue or some obstruction somewhere within the engine not letting fluid cool down the engine.
I would run a 195 or a 180, unless reprogramming the PCM to run on the cooler side you MAY get a code.
Is the radiator plugged up?
No, as mentioned previously in the post. Everything is new and was checked before hand. Save the rad tubes, those were from the og rad. Also, when the stat is not in I got full flow while test driving it.
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