cold side CAC blown off = no start diag

the_twig_187 · March 25, 2015

so today I had an interesting diag that I thought others may be interested in. 2011 f-550 (6.7L) no start with no codes. the only piece of information the customer gave us was that they herd a loud bang noise while driving and pulled over. poped the hood and found the plastic cold side CAC tube had blown off of the TB housing. I chased a bunch of different directions until I decided to call ford hotline and see what they thought. hotline said when ever you have a situation where the cold side CAC blows off its due to extreme backpressure due to a clogged exhaust system. the weakest link in the chain is the plastic cold side CAC and that is often what brakes the camels back when the exhaust cant escape as quickly as it needs to.

with this information I removed the 2 bolts on the downpipe and separated it. the truck fired up without issues, and will now need a DPF to fix the issue.

in conclusion= if you ever have the cold side CAC tube blown off go right towards a plugged exhaust system

p.s. not sure why there weren't any DPF codes or EBP codes in memory if it got to the point where the vehicle wouldn't even run

Buddy_M · March 25, 2015

I had a 6.4 no start once with similar outcome, except the CAC tubes didn't blow. Customer had just replaced fuel filters and thought air in the system, said it was low on power. Caught the EBP pid going way high on cranking on datalogger, broke the pipe loose on turbo outlet and fired right up. DOC inlet was completely plugged, had extremely high engine hours for the milage, and found out it was getting idled for excessively long periods of time at their shop.

cbriggs · March 26, 2015

I had a 6.7 with a code for a rail pressure problem. Drove with the cel on for 300km, plugged dpf solid. Apparently when certain codes are present it wont regen.

the_twig_187 · March 27, 2015

ohhh that's interesting. the company that own the truck has there own in house "mechanic". so we have no history and they wouldn't say if the check engine light was on or not before the no start condition. I priced out a retail DPF as they are way beyond warranty and they declined so they are towing it back to their shop and they are going to fight with ford to try and get it covered under warranty. my response to that statement was "let me get you the phone!"

leavnon3rd · July 9, 2015

just had one towed in for the same issue. popped on a new cac tube, cranked and it would sputter a bit and die. while cranking i had 43PSI on the EBP pid. turbo exploded. replaced that and the doc (damaged) and all is well.