Thompson 427 coolant contamination - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

cmack · 05-31-2022, 05:13 PM

Thompson 427 w/Darton sleeves...
I got bad oil report from blackstone, noted coolant contamination. I honestly thought they got my oil mixed up. They suggested a retest after 1000 miles on oil change, I pulled that sample today. The entire bottom contents of oil pan was all coolant. I don't really need report, it was all coolant. I am confused because oil has never looked like milkshake, normal used oil, even today. After the coolant drained out, the oil looked normal. This was a NA build, never had boost or nitrous. This motor has 6203 miles on it and has never overheated. I do track the car (road course) but it comes off track with coolant temps over 230. I don't know that this motor ever got that hot. I can't understand head gasket failure after 6k miles and no boost. ARP head studs.

Bo White · 06-01-2022, 12:39 AM

Sounds like a dropped sleeve or a cracked block.

cmack · 06-01-2022, 08:44 AM

I was wondering if the darton sleeves can crack . I did not even think of cracked block... (curse words...)

If it is, dropped sleeve - I assume they just resurface the deck? Or are these sleeves going to keep moving? and it's all just trash.

05-31-2022, 05:13 PM	#1
cmack Drives: 2011 Camaro SS Join Date: Sep 2014 Location: Texas Posts: 196 View My Garage	Thompson 427 coolant contamination Thompson 427 w/Darton sleeves... I got bad oil report from blackstone, noted coolant contamination. I honestly thought they got my oil mixed up. They suggested a retest after 1000 miles on oil change, I pulled that sample today. The entire bottom contents of oil pan was all coolant. I don't really need report, it was all coolant. I am confused because oil has never looked like milkshake, normal used oil, even today. After the coolant drained out, the oil looked normal. This was a NA build, never had boost or nitrous. This motor has 6203 miles on it and has never overheated. I do track the car (road course) but it comes off track with coolant temps over 230. I don't know that this motor ever got that hot. I can't understand head gasket failure after 6k miles and no boost. ARP head studs.

06-01-2022, 12:39 AM	#2
Bo White Drives: 2015 Summit White 2SS 1LE Join Date: Feb 2012 Location: Vance Alabama Posts: 8,019	Sounds like a dropped sleeve or a cracked block. __________________ Retired wanna be cylinder head porter 2015 2SS 1LE Clutch reservoir, Vararam DRX, ported TB, TSP 2" headers, MGW shifter Totalled: 2010 1SS Wilkes Performance/Eagle 416 shortblock, TSP custom valvetrain, PRC 260 heads, Edelbrock Pro Flo 102, th400 swap, 8" PTC 5500 stall= 535/435 at the wheels tuned Gen 3 Performance and Dyno 10.97 @ 124 full weight in 3100 DA CamaroFest X

06-01-2022, 08:44 AM	#3
cmack Drives: 2011 Camaro SS Join Date: Sep 2014 Location: Texas Posts: 196 View My Garage	I was wondering if the darton sleeves can crack . I did not even think of cracked block... (curse words...) If it is, dropped sleeve - I assume they just resurface the deck? Or are these sleeves going to keep moving? and it's all just trash.