OK... forgive the length of the post, but I want to asnwer some of your questions up front and give you as much pertinent information as possible.

Thanks ahead of time for your contributions and advice!!

WORK DONE:
- new 203°F t-stat and billet housing
- new top and bottom radiator hoses
- new coolant filtration system from water pump's HP port
- modified fittings on tranny cooler to allow my "new" 6.0L IC to drop in place
- complete coolant system flush and conversion to ELC

ISSUE:
I had a really hard time locating enough ELC coolant... could not get all Rotella ELC (had only 2 gallons of 50/50), got 6 gallons of Caterpillar ELC to go with teh Rotella (same exact stuff, but still 50/50), and then got 2 gallons of Havoline ELC concentrate to make sure I could ge to a 50/50 or 60/40 blend.

In filling last night, I started with the 2 gallons of concentrate (same as 4 gallons of 50/50). I had already completed the clean flush and rinse with distilled water first, followed by draining both the radiator and each block drain. Next, I topped off with another 4 gallons of the 50/50 which ended up giving me a total blend of 50/50 overall for the 8 gallon system.

Everything's fine, right?

Don't know... I noticed on the Havoline concetrate containers, while throwing them away, that it said it was Dexcool coolant, and did not say it could be mixed with "any color coolant" - it was red, anyway. All the other jugs - both Caterpillar and Rotella - said "can be mixed with any color coolant", and did not say that it was a Dexcool coolant.

OBSERVATIONS:
A) very slow to warm up compared to the way it used to be(twice as long), but at the same time, I don't know how old the coolant was before flushing and I DO know it was a gallon LOW.
B) Warming up this morning on the way to work took my needle only to the bottom of the little temperature emblem on the coolant temp gauge where it would normally get to full temp by the same time & distance.
C) The needle on the gauge did not move to full temp until I hit highway speeds several minutes later than when it would have in the past already been "at temp".
D) The needle is running about the width of the needle "hotter" on the gauge than it used to.

Here's the biggest question...

1) Did I screw up by using the Dexcool? Or am I ok?


Here is the next question, based on Observations cited above...

2) Is the temperature behavior I described above considered to be normal because of either having new and more coolant, higher temp thermostat, or both?

 

I'm not sure about the Dexcool, but IMHO there's no point to the coolant filter after doing a complete flush & switching to ELC. There are no SCAs left in your system to "flake off" and thus, no debris to catch. It's not going to hurt anything, I just didn't reconnect mine after my switch-over to ELC for those very reasons.

As for the slow warmup, being a gallon low (12%) might be part of the reason, and even though it's not likely, it could be that you have a faulty thermostat.

Not sure about the Dexcool question though... I know that's the big one, but I was able to get 4 Rotella ELC concentrate gallon jugs. Is there no International dealer or big rig/diesel shop near to you?

 

i don't think dexcool will mix with anything but dexcool. thats what i was told when i got some in the past.

 

When I went to the 203, and final charge antifreeze, I notice it takes longer to warm up. Dont notice if the warm temp on the gauge is any different, but i dont pay attention to OEM gauges, other then fuel, tach, and speedo. Technically your temperature should be a little warmer, since the 203 stat, is a higher running temperature. Also, after you have driven it, make sure to check your level again, some of the air may have surfaced.

 

I idled and revved the engine last night in the driveway for about 20 minutes until the temp started increasing, then drove it around for another 5-10 minutes. Then I had the 15 minutes drive to work this morning.

I noticed when I went out at lunch that it warmed up more quickly, and I'm beginning to think that the first two gallons of concentrate just had not yet mixed with the remaining fluids last night.

I've done some more digging and have found that the Dexcool really should leave my engine block tonight when I get home. I'm seeing way too much bad reports about it's incompatibility with other coolants. I don't want slugs of either gelatinous or otherwise chemically inappropriate mixtures running around my engine block.

Regarding the filtration system, I hear what your saying, but decided to go that route anyway due to what I've read in several places about how particles of silica break free from our "sand cast" blocks over time. Most of mine is probably cleaned out after 160,000 miles, but I want to make sure and went with the filter anyway.

I'll be checking not only the coolant level but also all the other potential leak points from all my work when I get home this evening.

UPDATE:
I found a Cat dealer fairly close by that has the Cat ELC Concentrate, which is identical to the Rotella ELC. Wish I had found them before because I was paying something like $12/gallon ofr the 50/50 mix, and can get the conctrate at this new location for only about $17/gallon which is less than my original cost.... except I get to throw away about $60 worth of coolant tonight to get the flush and fill done again! AAGHHHHH!!!

 

If you go to replace your coolant, Napa was able to order Final Charge. If you are having issue finding what you like.

Final Charge Antifreeze Home Page

I like this quote

600,000 miles or 12,000 hours of trouble-free protection, with the addition of FINAL CHARGE Extender at 300,000 to 400,000 miles of on-road use (3 years or 6,000 hours of off-road use).

300K until it needs its additive.

 

Darn, Pete. What a wast of money. I would do the same as you are saying, change it out. I would flush it all again also. I hate to see this happen, but it happens.

 

$60 of coolant is alot cheaper than a new engine. Gotta find the upside to every situation! Sorry to hear about the waste, but at least you'll be sure of things now. Don't forget to change that coolant filter too!

 

I didn't read this whole thread, but I can tell you that Dexcool has a very bad reputation for building up a nasty brown crust on the inside of the cooling system.
GET RID OF IT ASAP!

 

Ive seen that on the inside of the resovoir bottles of GM cars, since they seem to highly "pimp" the dex cool.

 

Pete, don't feel to bad, i did the same thing, i bought the Prestone ELC for duh, light duty trucks. Changed it out the next day with the CAT 50-50 per Joe(Izzy). Couldn't find the concentrate but it was ELC RED. My truck seems to take a little longer to warm up also, but when it does, it hot. Dexcool from what i read is a no-no, just for GM.

 

Thanks guys. I appreciate the confirmation and commiseration... we're all in good company, I guess!

Well, I have honestly gotten behind on cover orders, so I just flushed the engine with tap water, drained (not block drains yet), and flushed again with tap water just to make sure I get almost all of the yuck out and then left it for the evening with just the water in it... figured being full of water was better than being left empty to start rusting. I'll drive the old Suburban tomorrow and complete the flsuh with demin water and replace with the new Cat ELC coolant in the next couple of days.

I found my newly tapped in fitting on top of the trans cooler leaking when I got home right where I tapped into the billet piece... won't know if I either cracked it or stripped the threads a little until I can pull it out on Friday.

 

Good thing you checked.
ELC is expensive!

 

You're right Dan. The best part about it though is the first two letters... "EL"... for EXTENDED LIFE!

 

UPDATE: I've reachd closure to the above issues.

Friday and Saturday I completed the entire dump and flush cycles again, this time with 100% Caterpiller ELC coolant. I went ahead and replaced the t-stat o-ring since I had to remove it to get a good flush. This time, the warm-up cycle from the very beginning went much better, but this was probably also helped by the fact taht it was nearly 70 degrees outside at the time instead of the 30-ish weather when I finished it earlier in the week.

The leak at the new fitting on the tranny cooler seems to be resolved now as well. I had not used any thread sealant because I was out and wanted to complete the task. Got some new thread sealant the other day and that seems to have fixed the sisue altogether. Trannyis topped off, coolant is topped off, and everything's tight and dry, but I'll continue to check all the fittings over the next several days to make sure.

Oh... the new thread sealant I used was the Permatex gel-type in a screw-tube... really makes the application much, much simpler.

Thanks again everyone for all your input.