BMW Forum - BimmerFest BMW Forums banner
Cancel
Create thread New Garage Forums

Changed OEM coolant for Evans NPG+

Jump to Latest
26K views 38 replies 19 participants last post by  Whorse  
#1 ·
Today I changed the OEM coolant for the Evans NPG+ waterless coolant :bigpimp:
I know there is another thread about this, so I'm not gonna get into details of the pros and cons of it :tsk:

I will write about the change though: :p
1- lifted the car
2- removed the splash guard
3- drained coolant from the radiator plug
4- disconnected the hose that connects the electric wp and expansion tank (I left it attached to the expansion tank) and drained coolant from there
5- disconnected the hose from the top of the electric wp and drained some more coolant from there also
6- I disassembled the cooling system: took out the fan, fan shroud, expansion tank, thermostat and water pump. More coolant came out of the orifices where the thermostat and water pump go.
7- removed the engine plug and drained more coolant
8- I poured 2 gallons of distilled water into the thermostat orifice

Image


all the water came out from the engine plug getting rid of all the coolant that was left there.

9- I also did the same where the water pump goes.
10- I poured a gallon of NPG+ coolant into the thermostat orifice to get rid of all the water there. and poured about a quart into the water pump orifice.
11- Put everything back and filled up the system with NPG+ with about 1 gallon and 3 quarts.

I will be bleeding the system and filling up as necessary. :thumbup:
No more high pressure to worry about :rofl:
 
#5 ·
From bavauto

doru said:
Good for you Airos.
Are you sure you got everything out also from the heater core?
I am planning on doing this soon - it's still cold here to this - but the way I was explained was after you drain everything, including the engine block drain plug removed, to take off the hoses that go to the heater core. You want as much coolant out as possible.

Nevertheless, props to you.
Click to expand...
I believe the hose attached to the top of the electric water pump is one of the heater core, it goes to the firewall anyways; and 1 attached to the expansion tank also goes somewhere to the firewall.
Hoses #16 and #11 connect to the expansion tank. #16 connects to the electric pump and #11 connects to another hose. After those connections both hoses go to the fire wall.

http://realoem.com/bmw/showparts.do?model=DM63&mospid=47585&btnr=11_2638&hg=11&fg=35
 
#3 ·
Good for you Airos.
Are you sure you got everything out also from the heater core?
I am planning on doing this soon - it's still cold here to this - but the way I was explained was after you drain everything, including the engine block drain plug removed, to take off the hoses that go to the heater core. You want as much coolant out as possible.

Nevertheless, props to you.
 
#4 · (Edited)
Congratulations! Kudos to you for being one of the brave & bold, taking the waterless plunge for the team!

Do you have the high cluster? If so, what is your before/after reading on KTMP coolant temperature?

I, for one, haven't really comprehended the physics of the waterless philosophy, with regard to pros & cons; so I'm going to re-read these related threads to see if I can get a better handle on the physics & chemistry involved:
- Changed OEM coolant for Evans NPG+, by aioros ('99 528i)
- I did it! A zero pressure cooling system, by chiefwej (2003 540i/6 //m-tech)
- Solution to Exploding radiators (30psi/2.0bar pressure cap -> 20psi/1.4bar)
- The truth about Coolants (Evans NPG+ is 100% propanol and is thus non-aqueous)

For the record, I've read scores (or more) of cooling system threads and compiled what I think is a decent summary of what coolant to use. Like all summaries, it still needs work ... but I just now added the propanol references below for the record:

E39 Engine coolant: phosphate free (for Europe's high-mineral-content water), amine & nitrite/nitrate free (for USA long-life requirements), & low-silicate or silicate free (for Japan requirements) 50:50 mixture of ethylene glycol & water (the Bentleys say distilled water (Bentley 020-11), aka de-mineralized or de-ionized water, some call it purified water, and the BMW AG TIS 12.11.2007 18:56 specifies water with a pH from 6.5 to 8.0, maximum total hardness of 3.6 mmol Ca++/liter, maximum chloride content 100 mg/liter, and maximum sulphate content 100mg/liter; interestingly the BMW TIS says "potable tap water usually fulfills these requirements". EPA reports show San Jose & NYC tap water easily fulfill these requirements. The BMW TIS expressly states additives are not helpful and are not recommended. BMW lists a score of recommended coolants in their BMW AG TIS 12.11.2007 18:55 which meet the BMW N 600 69.0 standard, some of which are BMW PN:81.22.9.407.454 1.5-liter; BMW PN:88.88.6.900.316 1 gallon; Castrol Anti-Freeze NF; BASF Glysantin Protect Plus G48, & Havoline AFC (BD04); but most of which are not easily found in the USA. Many Bimmerfesters recommend BMW coolant; however other Bimmerfesters recommend Prestone Extended Life 5/150, Valvoline Zerex G-05, and Service Pro Universal Formula. Others (e.g., chiefwej, aioros), have tested Evans NPG+ but be aware propanol entails a different maintenance philosophy than the aqueous fluids listed above and is not compatible with them. [Total Volume: 1997 I6=10.5 quarts (2.6 gallons), 1997 V8=12.0 quarts (3.0 gallons), 1998-2002 I6=11.1 quarts (2.8 gallons), 1998-2002 V8=12.7 quarts (3.2 gallons), 1997-2002 V8 with latent heater=13.5 quarts (3.4 gallons)]. Prestone says the only reason for phosphate free is the extremely high mineral content of water in Europe - and that in the USA, it's not needed. Replacement Interval: Every three years (Bentley page 020-9) or every four years (aforementioned BMW AG TIS) starting from date of manufacture (except for M-Power vehicles which have 3-year intervals). Note: Mixing BMW-recommended coolant brands is permissible; but mixing types is not permissible unless it's an emergency.
Click to expand...
 
#6 ·
bluebee said:
Congratulations! Kudos to you for being one of the brave & bold, taking the waterless plunge for the team!

Do you have the high cluster? If so, what is your before/after reading on temperature?

I, for one, haven't really comprehended the physics of the waterless philosophy, with regard to pros & cons; so I'm going to re-read these canonical related threads to see if I can get a better handle on the physics & chemistry involved:
- Changed OEM coolant for Evans NPG+, by aioros ('99 528i)
- I did it! A zero pressure cooling system, by chiefwej (2003 540i/6 //m-tech)
- Solution to Exploding radiators (30psi/2.0bar pressure cap -> 20psi/1.4bar)
- The truth about Coolants (Evans NPG+ is 100% propanol and is thus non-aqueous)
Click to expand...
I think we posted at the same time, i didn't see your post after I posted mine.
Mmmh. What is the high cluster?
I believe that the temperature (or operational temperature) of the engine is not going to change. The whole cooling system will work the same, at the same temperature, and the engine as well. IMO the main reason to use NPG+ is NO PRESSURE, which eliminates most of the cooling system problems.
 
W
#15 ·
Bluebee only M5's have the sender for that reading on the dash. I was wondering if someone with an M5 converted to Evans so we can confirm the oil temp is still normal. Even thought the Evans gets up to normal temp does not mean its absorbing the heat from critical places in the block. I doubt the oil temp would be different but i just want to make sure. There's gotta be a reason manufacturers don't use it. Is it alot worse on the environment than regular coolant?
 
Save
Reply Quote Like Like
#16 ·
Whorse said:
Bluebee only M5's have the sender for that reading on the dash.
Click to expand...
Hmmm... are you sure? I have no clue but the realoem diagram above is from a 530i. Can a 530i be an M5?

Whorse said:
Is it alot worse on the environment than regular coolant?
Click to expand...
We should look up the material safety datasheet (MDS) for propanol.
 
#17 ·
ive had 2 gallons of this stuff for a long time now, but i held off because dont know where the drain plug on the engine block is located...i bought mine from Mooneyes in Cali...it was $35 a gallon and shipping was reasonable to hawaii...
 
#19 ·
We should look up the Material Safety Data Sheet (MSDS)
Click to expand...
Apparently Evans NPG+ ("Nonaqueous Propylene Glycol") is 'not' "100% propanol" (which was what someone had previously stated):
- All you wanted to know about Evans NPG+ (MSDS)!!

NPG stands for Non-aquous Propylene Glycol which is the base ingredient of the original NPG

NPG+ is a blend, according to the MSDS it contains about 25% PG
Click to expand...
I emailed Evans requesting their NPG+ MSDS and they emailed it back to me. ... Keep in mind that NPG and NPG-R are different from NPG+.

Summary of ingredients:

  • Evans NPG+:
    • Ethylene Glycol 66-70 %wt
    • Propylene Glycol %wt not specified
    • Water %wt not specified but from Evans webpage info it should be <3 %wt
    • Proprietary Corrosion Inhibitor Package <2 %wt
Click to expand...
Hmmm.... that sounds suspiciously close to "regular stuff"; I wonder what's so 'different' about the Evans NPG+ blend. We need to dig deeper.

Image
 

Attachments

#20 ·
Here is another MSDS (3/24/2009) for Evans NPG+ from this location:
- PerformanceParts.LongBrothers.Com Evans NPG+ MSDS (pdf)

  • Evans NPG+ (non aqueous propylene glycol blended coolant)
    • Ethylene Glycol (66% to 70%)
    • Propylene Glycol (no percentage listed)
      • Must be roughly 28% to 32% based on these numbers
    • Water (less than 0.10%, i.e., 'essentially' water free)
    • Corrosion inhibitor package (less than 2%)
Relevant properties apparently are:

  • Boiling Point is 375°F @ 0 psi
  • Freezing Point at -40°F
  • Viscosity - 2.3cp @ 212°F
  • Surface Tension - 44dyn/cm
Image
 

Attachments

#21 ·
#22 ·
To cross link the record, this was asked today:
Guam135i said:
Newbie question what is npg?
Click to expand...
I tried to put all the abbreviations used in the E39 forum over here:
- BMW E39 technoterms, acronyms, glossary, definitions slang, technical terms, abbreviations (1)
But, interestingly, even though I spent perhaps 100 hours on that one thread, I didn't list NPG unfortunately - so you wouldn't have found it there.

Luckily, the bestlinks has everything you need at the touch of a keyboard.
Typing /npg F3 in the best links, for example, netted this:
- A picture of every failed part in the cooling system (1) & various techniques to properly bleed (1) (2) (3) & refill (1) & drain (1) (2) & flush (1) & what coolant to use (1) & all about propanol-based zero-pressure fluids like NPG+ (1) (2) (3) (4) (5)

Clicking on those five threads, we find out this about NPG:
robertobaggio20 said:
8. There's a company called Evans that sells a zero pressure cooling fluid called NPG+ (this is a brand name). Its basically 100% propanol which (if i'm not wrong) is an isomer of ethyl glycol, and is thus non-aqueous i.e. does not involve any water. .
Click to expand...
chiefwej said:
Well, I decided that if I run a zero pressure cooling system, I may not have to do that next cooling system overhaul. No pressure, no exploding radiator.

So I ordered a case of Evans NPG+ waterless coolant. Not cheap at about $120, but if it saves an overhaul............... The case was 4 gallons. It took 12 liters (or about 2 3/4 gallons) to fill the system. That leaves over a gallon for top-ups, since you can't add water or any other kind of coolant with Evans.

I fully drained the system, radiator, lower hose, block drains, and ran the heater pump to get it out of there. I must have got it all because Bentley says it holds 12 liters and that is exactly what I got in it. So everything must have been out and there can't be any air trapped in there. After the NPG+ fill I changed the 2 bar cap for a 1.4 bar one.

With a boiling point of 375 degrees there should never be any pressure in the system now.
Click to expand...
bobdmac said:
Bluebee, the short version is that the Evans boiling point of 375 F means that the cooling system doesn't need to be pressurized to keep the coolant from turning into vapor (boiling) before it gets to the radiator to cool back down to operating temperature.

As aloros said, this means that the vulnerable plastic parts and hoses don't have the added problem of handling elevated internal pressures.
Click to expand...
So, given that I always try to put the answer to a question in the most likely place others will look for it, I'll add the following short description to the acronyms list:

NPG = A high boiling point (375°F) waterless (ethylene glycol based) coolant used to keep pressures in the cooling system close to zero bar (aka Evans NPG+)

http://youtu.be/t7PykrgzWPQ
 
#23 ·
I'm really confused here, but that's normal. Did the OP not say he put 2 gallons of distilled water into his system and then filled remainder with Evans or did I miss where he got the distilled water back out somewhere? The whole purpose is that you use 100% Evans and NO water, so why did OP use distilled water at any point?
 
#26 ·
Evans also sells a flush that you can use prior to the first fill that is supposed to flush all of the water from the system. That's what I did last year when I made the switch.
 
Save
Reply Quote Like Like
#28 ·
Correct. I just did not make the association that after adding 2 gallons of distilled water to the system that he then took it back out. I did not add-up all the Evans he added to see that he HAD to, to make room for 2.75 gallons. I never would have thought to use non-mineral-bearing
water to force out other water only to force the distilled water out with Evans, but that appears to be exactly the method. This stuff with a 1.0 bar cap or even less should be the cat's azz- ASPCA, don't comment!
 
#29 ·
So whats the consensus on this stuff? I just finished reading a 12 pg thread on it. Does it have a bad reaction with the metals and o rings in the engine? Does it cause the engine to run hotter? I assume it solves the problem of pressure related failures in the radiator and expansion tank.
 
Save
Reply Quote Like Like
M
#31 ·
honestly i wouldnt be so stressed about removing every bit of water. evans is just propylene glycol (and alittle bit of rust inhibitors etc) which is often mixed to 50/50 water for radiators anyhow. if i ever go w/ evans i wont stress abit little bit of water. it will work itself out in form of steam etc.
 
C
#32 ·
I've been running Evens NPG for 2 years now, coolant temp never goes above 98C and the car runs great. When I switched over I used the aux pump to remove as much water as I could then filled with Evens. For the next week I would open the radiator cap after driving home from work to let the left over water escape.

Chisum
 
R
#33 ·
been running Evans for 2 plus years also. not a problem. i still have a very minor coolant leak somewhere, but am not at all worried about it boiling off or anything. i have had an expansion tank break on me while i was running Evans and was still able to try home a couple of hundred miles away no problem. without the pressure in the system repairs can be easy. just some duct tape can take care of any hose leaks. expansion tank leaks are not a problem until the engine cools and the coolant settles back into the expansion tank. i am all for this stuff after reading about how fragile these coolant systems are. i know it is somewhat over hyped, but still knowing that without the pressure in the system any leaks will always be more annoying than catastrophic.

G~
 
Save
Reply Quote Like Like
B
#34 · (Edited)
Here in the UK, The Evans coolant is very expensive: seems approximately double the cost that you pay in the US.

This makes the thought of giving it a try a possible expensive mistake. They also charge an extortionate amount for the special flushing fluid. All in all, very expensive.

However, the thought of a lower pressure system is very tempting. But given all the concerns people have about using Evans coolant, I was thinking: why not simply increase the proportion of ethylene glycol to water? This would be much cheaper.

True, the freezing point of the mixture becomes unacceptably high as the proportion of EG to water increases. However, with a 90/10 mix of EG/Water, you get a freezing pint of -29C. This should be more than adequate for those who live in more temperate climates.

Additionally, a 90/10 mix of EG/water will not boil until +140C. This is a great improvement over the much lower boiling point of a conventional mix ratio and should result in a considerable drop in the operating pressure of the system.

This has the added advantage of using stuff that is already in your cooling system anyway, just in a different proportion.

The big question is whether a higher proportion of EG will cool the engine sufficiently. Any thoughts anybody?
 
#35 ·
I'm ready. After three times putting new Behr radiators in my 1999 540i I'm back to square one with leaks coming straight out of the top of the aluminum radiator underneath the shroud. No more cracks in the expansion tank or spews from the nipple. Oh no, now it's straight out of the metal at the crimps (or welds - who knows) all along the top. I am ready to pull the trigger and eliminate the high pressure that seems to wreck my cooling system over and over. I am ready to buy the Evan product and use it instead of the water-based BMW coolant. There I said it. So if anybody wants to chime in now's the time. Tell me why I shouldn't.
 
#36 ·
Evans NPG is still working well for me. No pressure, no problems. I even removed the top O-ring on the cap, to remove that last little trace of pressure (maybe 1/2 pound caused by liquid expansion). I have no interest in further debating the issue. I put it in my system, pressure gone, no problems, never looked back.

Before the change to Evans I went through 3 radiators in 40,000 mles. Desert heat is tough on cooling systems, it was 106 here today.
 
W
#39 · (Edited)
I'm 40k miles in on Evans NPG+ no problem other than when it got really cold here i had to add a 1/2 cup, looked like the big pipe that goes across the Vally pan sprung a spontaneous leak at the rubber seal. very weird happened once on the coldest day every since installing this stuff. once i started the car it hasn't leaked since. the valley pan is showing signs of micro leaks. I dont know if that's cause of the seal that comes with the new pan was bad or the NPG+ likes to seep??
I torqued the valley pan to spec and it seemed a little to tight for me. maybe the seal got squashed to much?

The other tiny problem using NPG+ cause is still there. My oil temps run 4-8 degrees higher than normal with bmw coolant. confirmed on 4 of my friends with e39 540s
 
Save
Reply Quote Like Like
R
#37 ·
works great for me also. i have a micro leak in one of my valleypan seals. i need to add 3oz every month or two. i could not imagine how often i would need to add fluid if the system was pressurized. i plan on redoing the vallypan seals when i go after my Vanos. i like the piece of mind of zero pressure.

G~
 
Save
Reply Quote Like Like
BMW Forum - BimmerFest BMW Forums
posts
12M
members
800K
Since
2001
A forum community dedicated to BMW owners and enthusiasts. Come join the discussion about Bimmerfest events, BMW production numbers, programming, performance, modifications, classifieds, troubleshooting, maintenance, and more! Bringing the BMW community together.
Full Forum Listing
Explore Our Forums
E90/E91/E92/E93 (2006 - 2012) E39 (1997 - 2003) E46 (1999 - 2006) E36 (1991 - 1999) E60 / E61 (2004 - 2010)