6 liter coolant flush

ghetto fireman · 10-09-2017, 09:34 PM

Going to tackle a coolant flush on my 06 6 liter. The block plugs look to be pretty accessible. Every post I read say to disconnect both batteries. Problem, mine are frame mounted and that would be a pain in the ass. What do you guys do?

Thanks

Mike

carringb · 10-10-2017, 07:36 AM

Disconnecting the batteries isn't necessary. Neither is pulling block plugs. Just use a quality chemical flush like Macs, and make sure the water is flushed enough times to be crystal clear before putting in new coolant, especially if you are changing chemistries (colors). Don't use the "all makes all models stuff". It won't react with existing coolant, so its fine for a top off. But the silicates are no bueno for a modern diesel with EGR. Ford/Prestone Gold/G-05 is ok if you drain and fill regularly. Cat/Cummins ELC is much better however, and can be left in almost indefinitely if you add a coolant filter, which i highly recommend.

JoeH · 10-10-2017, 09:58 AM

I'm leery of a chemical flush as it potentially can further clog the oil cooler with sludge. I'd only do it as a precursor to an oil cooler/EGR cooler job knowing that your going to replace the oil cooler anyway. Just my 2 cents but there's tons of crap in the Ford Gold as well as casting sand and you could potentially make things worse. If you want to flush it then have the dealer do it properly. You have to get the engine pretty hot to even open up the thermostat. 190F or so. Otherwise, if you want to switch coolant type then run 50 gallons of distilled water through it and refill. Other experiences may vary.

carringb · 10-10-2017, 10:38 AM

The dealer is going to use a drain and fill process as well. Most of the time you're paying for is waiting to the engine to get warm enough to open the T-stat. The purpose of the chemical flush is to re-dissolve the silicates that precipitated out of the coolant.

The Cat/Cummins ELC is a far superior product, but for a 10+ year old rig, chances are it'll blow a hose or some other cooling system component before the Gold stuff gets old enough to start breaking down.

FWIW - I've never had a truck come back with a plugged cooler after doing a flush and adding a filter. I have had trucks with a mild EOT/ECT delta that improved enough after doing the flush, to defer doing the EGR cooler.

ghetto fireman · 10-10-2017, 11:20 AM

This is just for maintenance, new to me SMB. Do you recommend a flush with ford chemicals? or simply drain and refill?

carringb · 10-10-2017, 11:55 AM

Yes, I recommend a chemical flush. Since you are new to it, it's likely the original coolant is starting to break down, and possible it's been contaminated with a high-silicate coolant if it's even been to a quickie lube and been topped off.

ghetto fireman · 10-10-2017, 02:09 PM

Quote:

Originally Posted by carringb

Yes, I recommend a chemical flush. Since you are new to it, it's likely the original coolant is starting to break down, and possible it's been contaminated with a high-silicate coolant if it's even been to a quickie lube and been topped off.

Looks as if the drivers side block plug won't be an issue. I plan on opening the radiator petcock, removing the 8mm block plug and flush thru the de-gas fill. Do I drain all existing coolant, then add the flush let the thermostat open and then flush again? Refill with 3 gallons of coolant and distiled water? Hesitant now after reading that it might plug my oil cooler after flushing.

JoeH · 10-10-2017, 02:20 PM

I defer to Carringb but I still don't like the idea of harsh chemicals but get the reasoning behind it if switching to an ELC since it has a chemical make up that is different from the G-05 Ford Gold.

Definitely install a coolant filter and here's a nice write-up of one way of going about the flush. Flushing and Cleaning the 6.0 - Ford Powerstroke Diesel Forum

Simply draining and refilling won't do it since 50% of the coolant will still be in the cooling system even after pulling both block plugs.

ghetto fireman · 10-11-2017, 06:45 AM

Quote:

Originally Posted by JoeH

I defer to Carringb but I still don't like the idea of harsh chemicals but get the reasoning behind it if switching to an ELC since it has a chemical make up that is different from the G-05 Ford Gold.

Definitely install a coolant filter and here's a nice write-up of one way of going about the flush. Flushing and Cleaning the 6.0 - Ford Powerstroke Diesel Forum

Simply draining and refilling won't do it since 50% of the coolant will still be in the cooling system even after pulling both block plugs.

Hesitant on performing the chemical flush, don't want to open myself to further problems just want to establish a baseline for a maintenance schedule. I see in your signature line your a landcruiser guy also, me too.

Best

Mike

carringb · 10-11-2017, 10:22 AM

Quote:

Originally Posted by ghetto fireman

Hesitant on performing the chemical flush, don't want to open myself to further problems just want to establish a baseline for a maintenance schedule.

Mike

I guess when you drain it initially, you can just check what come out then. If there's a bunch of sand, definitely consider a coolant filter. You'll never get it all flushed out no matter what you do, short of taking apart the motor.

If you find little tapioca beads, or any sort of goop that feels like silicone caulking, that's the silicates falling out of the coolant solution. This is not good to let stay in the system, and that's when you should consider a chemical flush. If you don't see any signs of silicates, and it looks like there's been no coolant types mixed, then a drain and fill is probably fine.