Steve Mutter Posted October 25, 2009 Share Posted October 25, 2009 I have a 2008 6.4 that I think will only loose coolant when towning because when I drive it I can never get the level to go down, so first off it came in with a damaged rad,replaced rad and installed tee fitting,customer said it still loosing coolant,replaced both lower rad hoses as there was coolant all around the coupler,tested and replaced horizontal egr cooler.still loosing coolant,so it looks like it is coming out the degas and leaking down the engine harness and making it look like the rad hoses are leaking,what would cause venting in this engine,can bad thermostates do this? the hotline wants me to look at the water pump but if I had cavitation would I not have coolant in the oil? any advice would be appreciated Quote Link to comment Share on other sites More sharing options...
Aaron Posted October 25, 2009 Share Posted October 25, 2009 Is it smoking or anything, or pumping it out of the bottle? Wash all the stains off the bottle and take it for a road burn and see if it farts coolant out. I just chased a 6.0 like this. Tee up a gauge in the cooling system yet to see what the actual pressure is? Quote Link to comment Share on other sites More sharing options...
GregKneupper Posted October 26, 2009 Share Posted October 26, 2009 Elongated thermostats will cause the coolant to blow out the bottle under heavy load. Monitor your ect while driving down the highway at a steady speed. If you ect fluctuates by more than 5 degrees your thermsotats need to be replaced. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted October 26, 2009 Share Posted October 26, 2009 Here is more information on the thermostat issue that Greg mentioned, it doesn't necessarily cover your symptom but pay attention to the diagnostic recommendation to see if you are dealing with hyper extended t-stats. 20922 - 2008-2010 F-SUPER DUTY - RADIATOR COOLANT LEAKS AND PCM CONTROLLED DERATE STRATEGY DUE TO HYPER EXTENDED THERMOSTATS SOME 2008-2010 SUPER DUTIES WITH 6.4L DIESEL ENGINES MAY EXHIBIT A LACK OF POWER WITHOUT DIAGNOSTIC TROUBLE CODES(DTCS), HIGH TEMPERATURE GAUGE READINGS AND REDUCED ENGINE POWER(PCM DERATE STRATEGY DESIGNED FOR ENGINE TEMPERATURE PROTECTION) DUE TO MALFUNCTIONING THERMOSTATS. DIAGNOSE BY MONITORING ENGINE OIL TEMPERATURE(EOT) AND ENGINE COOLANT TEMPERATURE(ECT) PIDS WITH IDS TOOL. WITH EOT AT 195 DEGREES F(90C) DRIVE UNLOADED VEHICLE AT 55-70MPH(88-(112 KPH) STEADY STATE SPEED WHILE OBSERVING EOT AND ECT TEMPS. IF EOT IS LESS THAN 8 DEGREES F(4.4C) HIGHER THAN ECT, AND THE COOLANT TEMP FLUCTUATES APPROXIMATELY 5 DEGREES(2.7C), THE THERMOSTATS ARE FUNCTIONING PROPERLY. ONLY REPLACE THERMOSTATS(8C3Z-8575-C)IF EOT EXCEEDS ECT BY GREATER THAN 8 DEGREES F(4.4C) OR IF ECT READINGS FLUCTUATE 10 TO 12 DEGREES(5-6C) EVERY 30 SECONDS. EFFECTIVE DATE: 07/30/2009 Quote Link to comment Share on other sites More sharing options...
Aaron Posted October 26, 2009 Share Posted October 26, 2009 Yeah, and the updated RT1212 thermostat number isn't even available yet. Quote Link to comment Share on other sites More sharing options...
LARRY BRUDZYNSKI Posted October 26, 2009 Share Posted October 26, 2009 Yeah, and the updated RT1212 thermostat number isn't even available yet. I see the 8C3Z8575B being S/S to 8C3Z8575C but nothing further than that. Looks like everyone has stock on the 8C3Z C's on Parts Voice. Quote Link to comment Share on other sites More sharing options...
Steve Mutter Posted October 26, 2009 Author Share Posted October 26, 2009 I did that ssm today and I have eot 190 and ect goes from 190 to 188,removed the water pump and inspected for cavitation,looks like new,there is no smoke,I have got the truck hot then park it over night in the shop to see if it leaks well cooling down as well,what could I be over looking Quote Link to comment Share on other sites More sharing options...
Aaron Posted October 26, 2009 Share Posted October 26, 2009 FWIW - the number from the SSM is superseded about 30587364 times in our parts listing, and it ends at RT1212, and that number doesn't show stock anywhere. Quote Link to comment Share on other sites More sharing options...
rlchv70 Posted October 28, 2009 Share Posted October 28, 2009 Other possibilities: injector and glow plug sleeves. Quote Link to comment Share on other sites More sharing options...
Steve Mutter Posted October 28, 2009 Author Share Posted October 28, 2009 Randy how would I go about testing for this? can you elaborate? Quote Link to comment Share on other sites More sharing options...
rlchv70 Posted October 28, 2009 Share Posted October 28, 2009 The way I would do it is to pressurize the cooling system and bore-scope each cylinder while under pressure. Use a flexible scope so that you can look back up at the injectors and glow plugs. Cracked heads or crankcase are also possibilities, but rarely seen. Have you pressurized the system to see how long it holds? You mentioned that you let it cool down overnight after a hot run. Did it leak then? Could this just be normal degassing after a coolant drain and fill? Quote Link to comment Share on other sites More sharing options...
Steve Mutter Posted October 29, 2009 Author Share Posted October 29, 2009 I got a change to talk to the customer and he told me that it did not matter if he was towing or not ever 200 kms he would have to add coolant,so I have driven this thing for the last two days and put over 300 kms have not lost any coolant,but everytime he has come back the degas tank was low,I have pressure tested it but my tester leaks,so I will have to try another one and see if it hold,I think I might be chasing a ghost,thanks all for your input Quote Link to comment Share on other sites More sharing options...
Steve Mutter Posted January 26, 2010 Author Share Posted January 26, 2010 just an update,the truck came back,cooling system pressure went to 30 psi,thermostats pass,performed fan clutch ppt pass so went to remove the heads and inspect,I found a failed head gasket on two cylinder #5 and #4,the right side cylinder head had grove in the fire ring area as well,there is a new looking headgasket,gold in color and it has less layers,customer has put 2000 kms and he called back and said it is 100 % now, Quote Link to comment Share on other sites More sharing options...
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