Well last week I traded my 03 6.0 in one a 08 6.4. Gonna get tuned when I have the spare cash. Well well the ac or heater.(does with both on) it makes a thumping or popping noise from right side in the front. Thought maybe vacuum pump but that is on the other side. No noise when heat or cool is off. What is going on? Compressor cycling? And if so is that Normal? Also when I was on a steep grade and disengaging 4 low in made a terrible sound from under truck twice and would stop once I put in park. Flat ground and slight grade no noise . Any ideas on these noises? Thanks
I get a similar noise... it comes and goes quickly about 2K RPM.
I have not yet replaced this hose to see if this is the issue or not. I will copy and paste the TSB below. This was pulled from a another site.
07-24-2 6.4L ENGINE BUILT BEFORE 06/18/2007 - HEATER CORE NOISE - ALSO DESCRIBED AS GURGLING, RATTLE, OR SCRAPING NOISE
Publication Date: November 21, 2007
FORD: 2008 F-Super Duty
This article supersedes TSB 07-22-2 to update the description in the Issue statement.
Some 2008 F-Super Duty vehicles equipped with a 6.4L engine and built before 6/18/2007 may exhibit a gurgling type noise coming from the heater core. It has also been described as a rattle or scraping noise. It has also been incorrectly identified as a torque converter concern.
Follow the Service Procedure steps to correct the condition.
Bring engine to normal operating temperatures.
Raise engine RPM to 2500-2900 range.
Using a hose clamp tool, crimp the heater inlet hose. If the noise goes away, replace the inlet heater hose.
If the noise does not go away, proceed with normal diagnostics.
NOTE: DO NOT ADD AN ADDITIONAL RESTRICTOR TO THE LINE OR MANUALLY MOVE THE EXISTING RESTRICTOR.
NOTE: DO NOT REPLACE THE HEATER CORE.
PART NUMBER PART NAME
7C3Z-18472-K Heater Hose (With Auxiliary Heat Controls)
7C3Z-18472-L Heater Hose (Without Auxiliary Heat Controls)