ddartford

I recently overhauled my 2009 LS3. I put a stage 1 Comp Cam. 222/234 @.05 and LSA of 113.

I had always baby'd my car for 122k. Valve lifer guide cracked,, lifter spun, and it ate a lobe. No bore. A hone and re-ring on the cylinders. They were only worn .001 to .003.

I have re-tuned the engine fir the cam with my original exhaust. Cats looked clear and I need to get it inspected. Headers are sitting in their boxes waiting...
The car idles well, throws no codes, but gets really hot waiting on traffic lights. I live in Houston and it is typically 100+ for the last few weeks.
When I am moving the ECT is 199. Sit in traffic and watch it go! After maybe 8 minutes idling the temperature peaks near 235 and occasionally 240! The fan is running flat out at this point. It no fun dumping the A/C and blasting the heater in the cabin.

I have "burped" the radiator/ gallery's to no avail.

I did notice that at traffic speeds I am in 6th gear and about idle rpm (750-800rpm) while going 50 MPH. I notice my spark is really retarding and advancing...from 12 degrees down to 2 or 3. This is only at a cruise. If I am into the pedal at all the spark behaves...steady climbs and falls when on and off the pedal.

Should I tune the transmission to be in a diffent gear (5th) under this driving condition. I think it will take some heat out of the block. Did I say that the heating starts immediately upon hitting stop and go traffic. It doesn't stay at normal Temps for more than a few seconds, then the Temps raise.
Spark is pretty steady at 12-13 deg when in gear and on the brake. Seems like the engine really want the resistance.

Radiator is new.

asd_srt

I've had a few cars come in with this issue and it's usually air still trapped in the system even if it's been burped it might have still had air in the system. What coolant are you running and what % coolant to water? When I lived out in El Paso i noticed having higher water % cooled better.

ddartford

I am using Prestone Antifreeze in slightly above 50/50 mix. It has a little more water. (-25F)...4 *****

You would think that eventually the air would circulate out...thru the steam vents???

phils C5 vette

I doubt it. You'd have more luck letting it run for 30 + minutes without the cap on.

asd_srt

I've seen a lot of LS with air pockets that never came up and vented through the steam vents.

tblu92

YES air pockets after a rebuild is common To avoid this overheating Try drilling 4 3/16ths holes in the thermostat base---This will allow the air to immediately be purged-- and will allow more coolant flow-----And have your fans to come on sooner than stock-----I always set # 1 on at 198* and off at 192 Then #2 fan on at 204 and off at 199 This is only with a 160 or 180 thermostat OR a stock 195 thermo with the 4 holes drilled