New LS3 based 427 heat issues. - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

kennyry83 · 10-01-2023, 08:43 PM

So newly installed 427 with Mishimoto radiator, new motorad 180 thermostat, new Delco water pump and Mishimoto hoses. Ran heater, and believe I have the system burped. This occurs during the day around 90f and mornings around 65f so ambient temperature does not affect it. As long as the RPM is above 2k temps will stay around 203, 2k and below including idle even while moving temps will creep up to around 225ish. Kinda at a loss on where to start first. I would think my cooling system is sufficient as I’ve seen others with the OE radiator with a similar setup with no issues. I was thinking maybe the thermostat may be bad and not opening all the way? Using the factory front two steam vents. Anyone ever have this issue or have any suggestions?

Aqua Blue RS/SS · 10-01-2023, 11:00 PM

What temp do your fans come on?

kennyry83 · 10-02-2023, 04:16 AM

Tuner set them to turn on at 195

larry_g · 10-02-2023, 06:08 AM

Are you running an under drive crank pulley?

Sent from my Pixel 5 using Tapatalk

kennyry83 · 10-02-2023, 08:29 AM

Quote:

Originally Posted by larry_g

Are you running an under drive crank pulley?

Sent from my Pixel 5 using Tapatalk

Ati balancer but stock pulley size.

gtstorey · 10-02-2023, 08:30 AM

Have you confirmed the fans are actually cutting on and at what temp?

Does it get warmer than thermostat setting at highway speeds in the cooler temps? If so I would suspect the thermostat is mislabeled or possibly the temp sensor. Check the temp of the temperature on the thermostat housing with a infrared temperature gun.

PaulsSS · 10-02-2023, 07:28 PM

Are the heater hoses capped?

kennyry83 · 10-05-2023, 01:45 PM

Quote:

Originally Posted by PaulsSS

Are the heater hoses capped?

No, connected to heater core and heater blows hot when on.

kennyry83 · 10-05-2023, 01:47 PM

Quote:

Originally Posted by gtstorey

Have you confirmed the fans are actually cutting on and at what temp?

Does it get warmer than thermostat setting at highway speeds in the cooler temps? If so I would suspect the thermostat is mislabeled or possibly the temp sensor. Check the temp of the temperature on the thermostat housing with a infrared temperature gun.

Ya the thermostat is a 180 motorad, gets way hotter.

I actually got a new Ligenfelter 160 thermostat and bought a new temp sensor and plan on replacing both this weekend. Crossing fingers!

gtstorey · 10-05-2023, 01:58 PM

Might still be air bubble also. These can be very hard to bleed without a vacuum coolant fill.

InFiD3ViL · 10-06-2023, 09:54 PM

Quote:

Originally Posted by gtstorey

Might still be air bubble also. These can be very hard to bleed without a vacuum coolant fill.

This is my guess. Notoriously difficult to bleed properly.

kennyry83 · 10-08-2023, 01:58 PM

Well looks like it was the thermostat. Ended up replacing it and went with a 160 instead of a 180. Boiled the one I removed in a pot of water and it didn't start cracking open until close to 195. Max temp now with the 160 thermostat is 195 in traffic idling and 180 cruising, way better and which I assume is probably the limits of my cooling system.

10-01-2023, 08:43 PM	#1
kennyry83 Drives: 2011 Camaro SS Join Date: Aug 2023 Location: Oklahoma Posts: 21	New LS3 based 427 heat issues. So newly installed 427 with Mishimoto radiator, new motorad 180 thermostat, new Delco water pump and Mishimoto hoses. Ran heater, and believe I have the system burped. This occurs during the day around 90f and mornings around 65f so ambient temperature does not affect it. As long as the RPM is above 2k temps will stay around 203, 2k and below including idle even while moving temps will creep up to around 225ish. Kinda at a loss on where to start first. I would think my cooling system is sufficient as I’ve seen others with the OE radiator with a similar setup with no issues. I was thinking maybe the thermostat may be bad and not opening all the way? Using the factory front two steam vents. Anyone ever have this issue or have any suggestions?

10-01-2023, 11:00 PM	#2
Aqua Blue RS/SS Drives: ABM #93 Join Date: Oct 2018 Location: Lotaburger Posts: 2,709	What temp do your fans come on? __________________ ABM #2399 2SS/RS:SOLD ABM #93 2SS/RS Black Rally stripes, Titanium Interior 4,000 miles: GM GFX side skirts and diffuser waiting on paint, GM dovetail, GM heritage, RPI ZL1 style splitter. ‘87 IROC-Z Iroc blue. all original unmolested with 50K miles.

10-02-2023, 06:08 AM	#4
larry_g Drives: 2014 1SS/1LE Join Date: Nov 2015 Location: Louisville, KY Posts: 826	Are you running an under drive crank pulley? Sent from my Pixel 5 using Tapatalk __________________ 830 WHP 700 WTQ, Whipple 2.9 @ 13lbs Boost, Flex Fuel Tune by Blevins Tuning, LSA SBE, 3.5 GripTec, ATI LS3 Damper, AFR 260cc Mongoose, ARP Studs, Yella Terra Ultralites, Johnson 2110R, BTR PDS Stage 3, Melling 10355, Improved Racing Baffle, ID1050X, DSX Triple Fuel Pump, RotoFab CAI, NW 103mm TB, Stainless Works 1-7/8" LTH to 3" Speed Eng w/ X-pipe to NPP, Powermaster 9509 XS, Detroit Speed Motor Mounts, MGW, Monster LT1-S, ZL1 Calipers, DBA Rotors & Pads, Bilstein B6 Struts & Shocks, BMR 1.25" Drop Springs & Adj Rear Bar, Pegasus Solid Bushings, Z/28 Wheels, other misc parts.

10-02-2023, 04:16 AM	#3
kennyry83 Drives: 2011 Camaro SS Join Date: Aug 2023 Location: Oklahoma Posts: 21	Tuner set them to turn on at 195

10-02-2023, 08:30 AM	#6
gtstorey Drives: 2010 Camaro SS2,L99, LSA SC Join Date: Aug 2017 Location: Huntsville, AL Posts: 2,178	Have you confirmed the fans are actually cutting on and at what temp? Does it get warmer than thermostat setting at highway speeds in the cooler temps? If so I would suspect the thermostat is mislabeled or possibly the temp sensor. Check the temp of the temperature on the thermostat housing with a infrared temperature gun.

10-02-2023, 07:28 PM	#7
PaulsSS Drives: 15SS Camaro Join Date: Dec 2020 Location: US Posts: 347	Are the heater hoses capped?

10-05-2023, 01:58 PM	#10
gtstorey Drives: 2010 Camaro SS2,L99, LSA SC Join Date: Aug 2017 Location: Huntsville, AL Posts: 2,178	Might still be air bubble also. These can be very hard to bleed without a vacuum coolant fill.

10-08-2023, 01:58 PM	#12
kennyry83 Drives: 2011 Camaro SS Join Date: Aug 2023 Location: Oklahoma Posts: 21	Well looks like it was the thermostat. Ended up replacing it and went with a 160 instead of a 180. Boiled the one I removed in a pot of water and it didn't start cracking open until close to 195. Max temp now with the 160 thermostat is 195 in traffic idling and 180 cruising, way better and which I assume is probably the limits of my cooling system.