Yep. Pulled the intercooler to replace the rad (sprung a leak, probably my fault, looked like the fan shroud rubbed it) with a mishimoto stock replacement rad, and noticed the lines were full of brownish sludge which felt distinctly not like scaling (which the iron in the block will still do). I think the photos are still on my radiator thread, recounting my incompetence with intercooler boots and the utter mess of oil film which flushed out of the intercooler after soaking it in purple power.
Before pulling the old IC (edit: RADIATOR) the leak had been steady enough (filling a 15qt drip pan in ~12hrs) that I’d given up even putting distilled water in while waiting for the mishimoto rad to show up, so once I got shipment confirmed I dumped in a bottle of coolant system flush, drove it two round trips to work (~100 mi total), dumped in another bottle and drove two more shifts, then pulled the rad for the swap and flushed the block and lines with purple power. Used about half a dishwasher load of dishwasher detergent (powder) to do a final flush, rinsed it for several minutes with the thermostat removed (housing still mounted) and the lower rad hose pinched mostly closed. Also left the coolant filter off (replaced it) and the lines cracked so it’d flush the back of the head as well.
Did a bunch of sniffing and decided to not bite the bullet for $40-some a gallon for mama mopar HOAT-flavored koolaid, and just used zerex premixed lemon-lime faygo from the Wally World. MUCH cheaper and says compatible with FCA vehicles; I don’t think it’s as big an issue as I flushed the whole system tho, so it’s not like anything was getting mixed. Ended up being about 5 gallons for a full topoff from 30psi vacuum after blowing it all (or at least mostly) out with compressed air and getting the coolant checker to say it was good to go.
Bought 8 gal for less than I could get 2 at the stealership... so now I’ve got 3 extra just chilling on the shelf collecting dust cuz my stupid self opened them all anticipating needing 7+ gal
Addendum: if you think you have to do a water pump, loose your belt and have a sniff at your tensioner and idler pulley too. While the belt is loose is a great time to scoot it around and look for cracks, as the belt is like $18 - almost not worth NOT doing since it’ll be off anyway. The idler and tensioner are cheap and really easy to get at while you’re already in there for the pump as well, pretty sure I got everything from Genos (belt, Gates pump, idler, tensioner, and the fan clutch wrench) for ~$150ish. If you get belt squeak when it goes back together, saw a YouTube vid where the firepunk crew sprinkled some comet powdered cleaner on the belt down at the harmonic damper and it quieted the belt right up.
Considering that we're still under 50K miles on the odometer -- and that we've never had a leak requiring any emergency additives (i.e., Bar's Leaks) -- would you still recommend that we go through this rigorous flush sequence?
Loooong long ago, when we were still in Dixie, I added a flush treatment to my wife's car and, long story a bit shorter, the damn heater core developed a leak. Given the design of this particular vehicle, all was well: until you turned on the heater
. I must've blocked it out of my mind, but my [new] wife had me remodeling the dog house for quite some time after that one. Not that I'm holding you to anything, but do you think that we necessarily need such a great flush job?
I'm also wondering if you did the belt work on your own?
You must've read my mind, but Geno's already sent us the Cummins water pump (Part No. 5473238
the Gates "Complete Serpentine Kit" (Part No. 90K-38285
) ... and, for those just tuning in, this kit comes with a complete belt tensioner assembly, a new serrated belt pulley (not part of the belt tensioner assembly) and a Gates HD belt ... which leads me to another question: Did you use one of them new-fangled "Serpentine Belt Tension Tools" (Part No. WLMW84010) to do all of this work?
I've watched a nice YT video where a young guy used a ratchet handle to loosen the belt on his 6.7L CTD, but this process required a "lovely assistant." I usually can't even interest an ugly assistant; hence, the questions. The length of the tool shown on the Geno's website suggests that it's intended for solo removing/installing the serpentine belt, so now I'm wondering if I screwed the pooch by not ordering it.
If I do end up ordering the aforementioned Serpentine Belt Tension Tool from Geno's, do you also recommend investing in a fan clutch wrench set?
I noticed that you mentioned a fan tool in a prior post; hence, this question. I can still recall the nightmarish battle I had with the fan on our '98.5 24V 5.9L CTD, so, considering that you've obviously done extensive work on the front of your 6.7L, I'd be much obliged for your thoughts on these tool kits.
LINK TO SERPENTINE BELT TOOL KIT
LINK TO FAN TOOL SET
Have a good one down in Dixie