Bradlyj8Z28

iTrader: (2)

I completed my LS1 swap 2 and a 1/2 to 3 years ago. Never had a problem with overheating. I am in Fresno CA now after a transfer for my job in the Army. Outside temp today is about 105. While driving without ac, it quickly reaches 200, then slowly but surely climbs to 225 then 230. Then I shut it off for fear of hurting something.

My radiator is a 3rd gen radiator that is only a few years old. I recently flushed it, used prestone cooling system cleaner, did roughly a 50/50 bottled water and prestone extended life mix with a bottle of water wetter. I installed a new 187 degree thermostat. When I filled my cooling system I did it with the engine running and verified a good flow so I know my water pump works. When it got low, I topped it off until full. I also installed a new radiator cap, 16 lbs which is what the LS1 and TPI motor called for.
I have my original TPI dual fan set up. Both of my fans are set up to come on at 200 degrees. My air dam is there and in good shape.

Whether idling, or driving down the road my car still creeps up to the 230 mark.

So my questions are, why? I thought with a good functioning cooling system outside temp wasn't relevant. How hot is too hot for an outside temp?

Second, if its a head gasket, wouldn't it heat up faster? Also, I always though that I would have oil in the water, or water in the oil? Is that not true?

I have an oil cooler I am going to install this weekend. It was in the works anyhow, but if it fixes my problems great.

Any help would be appreciated!!!

JTNKTZ

iTrader: (10)

Are you loosing water?

Bradlyj8Z28

iTrader: (2)

I don't have any water on the ground. My overflow seems to be staying at the same level also.

one92rs

iTrader: (5)

how recently did you flush it. just before the overheating started?

Bradlyj8Z28

iTrader: (2)

I did the flush after the first time it got up to 230.

1bad91Z

iTrader: (1)

Another probable scenario...

Most likely one or both fans are not coming on or they are getting weak and not moving enough air. If you can see both fans come on, get a lower temp cool fan switch or program them in the ECM to come on at a cooler temp and see if that may help.

Bradlyj8Z28

iTrader: (2)

I have verified both fans are coming on. Both fan motors are new. How can I tell if the are not running fast enough or moving enough air? I put my hands on both sides of the radiator and can physically feel air being moved.

86 LT1

Make sure there are no air pockets in cooling system sometimes it takes awhile to get all the air out recommend turning fans on earlier and lower t-stat are you using aftermarket temp gauge?

Bradlyj8Z28

iTrader: (2)

What is the best way to bleed air off? I thought I did it right but perhaps not. I am running the stock gauge with an 02 temp sensor. I also have an Aeroforce digital gauge hooked up the the obd II port and that is the one I am going off of.

86 LT1

just keep filling at idle had the same probs with my LT1 swap water was circulating fine then after awhile it would "burp" some air and take more water,all my LT1s run a manual switch to turn the fans on sooner and 160 t-stats after that no more running hot there is also an additive you can get at autozone that lowers temp by 10 degrees used that already and seemed to help before the other changes we made,

1ADan

iTrader: (4)

probably dumb question, but what did you do for the steam lines? how did you run them?

Bradlyj8Z28

iTrader: (2)

Heres a pic showing what I did, but again 2 1/2 plus years no problem

one92rs

iTrader: (5)

i think the steam tubes he was asking about are the steel crossovers that you have. do you know anyone with an inferared temp probe or gun. that way you can see if the coolant in the radiator is getting hot as well or if it is the engine only. another thing when it is idling can you see the coolant circulating. what i usually do is drain a little coolant till it is below the 2 top rows of fins. then let the car idle to see if it is circulating when hot. on the fans they should be spinning pretty fast.

Bradlyj8Z28

iTrader: (2)

I went from Texas, hot but humid with a freeway commute. To Fresno CA, dry heat city driving and am now having getting hot issues. I have a March underdrive pulley that has been on for about 2 years, is it possible that I slowed my water pump down too much and that is my issue? Even with my newly installed oil cooler I am running a solid 220-221 temp with the AC on.

Bradlyj8Z28

iTrader: (2)

Just to close this out, I did a head and cam swap and it was a bad head gasket on the passenger side.