Coolant questions

[3x5]

COOLANT QUESTIONS

We have a 2005 Alpine 36 FDDS with a Cummins ISL 8.9L 400hp diesel engine which we bought about 3 years ago. It has 87,000 miles. I have heard about the importance of maintaining diesel engine coolant properly to prevent cavitation of the cylinder walls which can ruin the engine.

I am burned out trying to get to the bottom of this, and now my head is about to blow up.

KEEP SAME COOLANT?

I think our rig has Cummins Fleetcool in it, which is a DCA 2 type. It is green and when I test it there is zero molybdate but plenty of nitrite. I am guessing that this is the original coolant. Is this what Western RV put in these coaches?

It tests good for freeze point and nitrites with the Cummins CC2602 test strips. I haven't had to add anything yet. Now I found out that I am supposed to be testing for contaminates too with a CC2718. I haven't been able to do that yet.

Should I just continue with this coolant indefinitely? Should I upgrade to a DCA 4 coolant or an OAT coolant? This coolant is fairly old, so I am tempted to just have it flushed and replaced with the OAT for simplicity.

Has anyone changed over to OAT? How did that go? What kind of testing and maintenance does OAT require?

COOLANT CAPACITY?

Does anyone know the coolant capacity of our rig? Even just the amount that drains out and a guess for what is left?

WHICH THERMOSTAT?

I think I should just change the thermostat at the same time. Does anyone have a model number for it?

By the way, I notice that my engine temperature quickly goes up when I climb the smallest hill. (Sorry, I can't remember if it goes up to 175 or 200 degrees.) Is this normal for a Cummins diesel, or would a different thermostat even it out?

HOW TO ADD A FILTER?

The 2005 Alpines didn't come with a filter. But at the end of the Cummins Service Bulletin 5411406 they recommend one. They say that tests show that filters always catch some scale and debris. Should I add a filter?

I see that Cummins has a kit (257715 S) with a filter spin-on head (204163 S) and mounting bracket assembly (256535 S). They also have a Severe Duty Water Filter Head (3904378 S).

Has anyone added a filter? I hear that there is a premade place made on the engine to attach one. Does anyone know where to look for it?

Thanks for your help.

[Alpine06]

Wow looks like we spend our day doing the same thing.
I did not envision that the coolant topic could be this difficult and complex.
I will need to unhook the lower coolant pipe and see if I can paint it or if it is rusted out too far and I need to make a new one. So today I drained all the coolant out (or most of it 11.8 gal).
I decided to refill with ES Compleat EG 2820 and ordered directly from Cummins filtration with free shipping. I decided not to flush as it is not necessary. What I did not think of was the aquahot it also holds coolant, well I still can drain that once I get that pipe of. Most likely the upper steel pipe can be saved and some new coolant hoses will need to be installed while I am at it.
I decided not to install a coolant filter as the SCA adding through the filter will not be necessary.
Cannot really help you with the other questions but doing the thermostat as a preventive sounds like a good idea - possibly also the cap for the coolant surge tank.
Joerg

[Alpine06]

Originally Posted by Alpine06

Wow looks like we spend our day doing the same thing.
I did not envision that the coolant topic could be this difficult and complex.
I will need to unhook the lower coolant pipe and see if I can paint it or if it is rusted out too far and I need to make a new one. So today I drained all the coolant out (or most of it 11.8 gal).
I decided to refill with ES Compleat EG 2820 and ordered directly from Cummins filtration with free shipping. I decided not to flush as it is not necessary. What I did not think of was the aquahot it also holds coolant, well I still can drain that once I get that pipe of. Most likely the upper steel pipe can be saved and some new coolant hoses will need to be installed while I am at it.
I decided not to install a coolant filter as the SCA adding through the filter will not be necessary.
Cannot really help you with the other questions but doing the thermostat as a preventive sounds like a good idea - possibly also the cap for the coolant surge tank.
Joerg

Ok for some reason I cannot edit my above post. I misspoke on the filter and SCA topic, the coolant I mentioned above still needs DCA4 additions. The OAT mentioned by the OP will not.
So I don’t want to spend a whole day flushing and this is why I decided on the ES Compleat.

[3x5]

So Joerg, what kind of coolant did you start with that you added the ES Compleat EG 2820 to?

[Alpine06]

3x5,
I also had most likely the original fleetcool green EG coolant with SCA addition. I tested the coolant twice in the past year and a half.
I think that the new coolant will be very, very slow in consuming it’s additives.
The part I regret buying the Compleat is that it is blue. I plan to carry a gal of concentrate but if I ever had to add a different coolant in a pinch the color would get ugly in a hurry.

[Bruce Anthon]

I have a 2003 ISL 400 that I purchased three years ago. It had green coolant that was regularly maintained and tested by the previous owners. I decided on switching to Fleetgaurd OAT. I used Fleetgaurd Restore Plus to flush the system. Be sure to keep your chassis heater core on in order to flush it as well. I added heater core shutoff valves at the engine also. There was a moderate amount of scale and sludge in the catch can when this process was completed.

Thermostats usually work or fail. It’s a very easy change and after 15 years I would if I were you. I got mine from Cummins and used the engine serial number to be sure I got the correct updated part.

My unit has a water filter so I just switched to a filter only no additive type. Newer Cummins engines do not use the coolant filter option and I would think with a flush it would not be needed. Oat will eliminate coolant test strips and additives. Simple and not much more expensive.

Temperature cycling that you mentioned is usually indicative of radiator heat dissipation and cooling fan cycling. There are many threads on this process. I flushed the outside of my radiator, a/c cooler and aftercooler and was amazed at what came out that was not obvious to the eye from both sides. I used Simple Green extreme ... sprayed a directed, let soak and flushed with just garden hose water pressure (no pressure washer). I sprayed from the inside out - engine side out. Try this first. If the temp still rises than look at the cooling fan control. There is a normal cycling on the temp gauge as the cooling fan control kicks in and cools the radiator. That is independent of the engine thermostat.

I also changed the water pump and belt tensioner in the same process. With the coolant out it makes many jobs easy. The water pump added 30 minutes to the whole job. Let me know if you have any questions as you get into it. Good luck!

[3x5]

Many thanks, Bruce. Good info. I'll just flush and change to OAT.

[jacwjames]

As far as I knew my coolant was original. I had been using the strips to test it and it never changed and I started to question that type of test. I didn't have a good place to do it so I got a quote from the Cummins shop to do a flush and change The manager recommended I test it first so I took a sample and sent it JG Lubrication. The results came back great, essentially like new. This was early in 2015

In May 2015 we were headed back home and road debris took out my radiator. Had it towed to the Cummins shop and ultimately got it changed and the shop manager recommended I use the ES Compleat.

[3x5]

Originally Posted by jacwjames

As far as I knew my coolant was original. I had been using the strips to test it and it never changed and I started to question that type of test. I didn't have a good place to do it so I got a quote from the Cummins shop to do a flush and change The manager recommended I test it first so I took a sample and sent it JG Lubrication. The results came back great, essentially like new. This was early in 2015

In May 2015 we were headed back home and road debris took out my radiator. Had it towed to the Cummins shop and ultimately got it changed and the shop manager recommended I use the ES Compleat.

Its the exact same thing with me. I am starting to doubt my test strips. Good to know that the lab test was good too.



Which version of ES Compleat did they recommend? The OAT which is red?

[Old Scout]

jacw--my local Cummins shop manager [who I have worked with for years] gave a similar recommendation on not changing over from ES Complete vs OATs--not sure why....as long I was testing for SCA and freeze point--he was also somewhat ambivalent about when to change coolant, eg, mileage or age....contamination would be the primary concern over time. my 2003 era Cummins also has a coolant filter -- some say there is some benefit to having the filter trap scale or other debris--not sure its that important. Opinions vary.

[Winemaker2]

I've been right in the middle of a similar frustrating exercise to decide what to do with my Newmar VTDP on FL chassis with Cummins ISB eng.
What Ive learned so far...( only applues to ISB)
Still trying to figure out what is in it now but believe it is FL factory original (pink)as I have previous owner FL Gafney service record.
Cummins states SCA not required and other types of ELC coolants acceptable (OAT, HOAT...)
FL cautions that while SCA not speced by Cummins that FL REQUIRES conventional Non ELC Fully Formulated coolant due to their coolant system sensors. If not used we risk error signals and engine down grade / shut down due to those error codes.
Fl was adamant against using any ELC coolants including those approved by Cummins!

I plan to elaborate more in a separate post specific to FL & ISB eng as there are differences and I dont want to confuse this discussion... just wanted to pass along the FL comments.

[Brianna]

My 2000 alpine is new to me last summer.

This spring I took it to cummins with a laundry list of preventative maintenance.
When it came to the coolant they said it's fine, don't bother spending money on a flush/fill.

Seemed really counterintuitive but I figure they know best.

[Alpine36]

Originally Posted by Brianna

My 2000 alpine is new to me last summer.

This spring I took it to cummins with a laundry list of preventative maintenance.
When it came to the coolant they said it's fine, don't bother spending money on a flush/fill.

Seemed really counterintuitive but I figure they know best.

Hopefully they changed your coolant filter. (Fleetguard WF2074)
That filter has a fresh charge of DCA built into it and should be changed at least bi-annually. I have it as an annual thing on my maintenance "checklist".
A coolant sample should be done annually and tested with fresh test strips. Both are very simple DIY tasks. Saying it's fine and knowing it's fine are two completely different things. Only you can know for sure. Just my .02c

[Brianna]

Coolant filter. Thanks 36, good safety tip.
Adding to my list.
I don't want to stray off topic, but what's your take on the 2 Allison filters? Routine change or wait for indications?