View Full Version : Suplemental Coolant Additives

08-22-2004, 09:26 PM
Ok, so I have heard that with diesels that you need to add suplemental coolant additives to the coolant and to check often to make sure that the levels are up to prevent cavitation. So I bought some strips and sca but I dont know where the levels are supposed to be at.

My test strip says that I have 50% glycol and a ph of 8. Anyone know what its supposed to be at?

My truck is a ford '93 7.3L, idi turbo diesel

08-22-2004, 09:54 PM
cavitation? Do you mean corrosion? Your test results sound OK to me. I do know this, DO NOT run more than a 70% glycol mix. Anti-freeze/ anti-boil coolants are not to be used at 100%. Most people do not know this. Above 70% there effectiveness in fact may go down. I have heard that 100% glycol will freeze and boil quicker than a 50/50 mix. I do also know that in today cars and trucks gas and diesel you can not use plain water as you once could. Take my '77 Dodge for example, it has a water jacket temp of 180* F, cars now days run with water jacket temp of up to 240*F. I thank that is one reason engine do not last as long as there use to.

08-22-2004, 10:32 PM
Cavitation explained,


08-23-2004, 02:31 PM
He meant cav. It's the big C word in diesel ownership. Problem was the 6.9 had thicker cyl. walls so it did not show up. Since the 7.3 is a punched 6.9 it is seen more. Later on Ford added it to the engine at the factory and published info on it. The IDI crowd never had Ford document SCA. I highly suggest you join and visit this crowd Ford Diesel (http://www.thedieselstop.com/) I cannot remember the correct reading on the strip. Do a search on cavitation and you will find what you need.

More than you ever wanted to know!

BTW I have a '93 CC Dually 7.3 IDI NA

08-23-2004, 06:31 PM
you need an SCA coolant additive from ford it is $6.00 last time i bought one each bottle brings the system up about 3/4 to one point. If you flushed your cooling system you need around 3 or four bottles I think. I think fords SCA additive is called FW or DC-16? Just ask for SCA additive. You can also get it from Fleetguard and International. I have found that international is the cheapest.

08-23-2004, 07:00 PM
I have been out of mechanicing for 2 years now. When i was a truck mechanic we called it DCA. It is an additive to keep down corosion and help elimanate air bubbles in the cooling system. We were always told that air bubbles would get in the system and the heat wouldnt be taken away from the clycinder walls and would actually heat up and melt a hole in the liners/cyclinder walls. The product we used was called nalcool. I dont know the proper levels but the test kits we had would change colors and there was a chart to go by as to what was acceptable. The factory reps told us that having the system overcharged wouldnt hurt anything. I think 2 pint bottles would be ok to add to the system

08-24-2004, 01:40 AM
Thanks for the help guys! I was looking around on thedieselstop.com but there were no references to what the colours on the strips should be.

08-24-2004, 04:51 PM
Go here. FleetGuard (http://www.fleetguard.com/fleet/pdfs/product_lit/fleetguard_brochures/LT15068.pdf)

The results should be shown on the bottle / package. Call FleetGuard direct if need be.

08-26-2004, 09:57 AM
Here is a picture of cavitation on a sleeve. These sleeves are out of an International DT-414 engine (smaller brother to the DT-466 used in trucks) with 7,200 hours on it. Besides the DCA be sure that you are using anti-freeze that is designed for diesel engines and not the high silicone stuff sold at auto part stores that is for aluminum block engines. We have started buying Fleetgaurd Complete coolant which already has the DCA in it but it is pricey in gallon containers (we buy it in bulk which cuts the cost alot.