New 310R Coolant Issue

[Randy Flowers]

Hey yall

 

Another new issue just popped up.  I noticed today that there was no coolant showing in the reservoir in the nosecone area. This is the first time I noticed the coolant being low. So, 2 questions:

 

1) There is no coolant leak that I am aware of. Also, the engine hasn't been getting too warm.   How do I best track down why it is now low?

 

2) I am pretty sure the original coolant in the reservoir was blue.  The owner's guide is specifically pointing to only using their recommended coolant (Motul which can only be ordered from overseas). 

 

Given that we are in the USA, what can I easily order (Amazon?) for coolant?

 

I will need to top it up again enough to get it over to my mechanic friend's garage so he can figure out what is going on.  Right now, the car is parked in its storage unit.  So, I will need some sort of coolant put in for that and don't want to put in something that I shouldn't put in it.

I have never personally changed/flushed (or bled) coolant before (my Miatas over the last 3 decades have never lost coolant that I can remember), so I am learning on this subject for sure. 

 

I definitely do not want to burn the new Ford Sigma engine up!

 

Thanks!

Randy

[CBuff]

Not sure what year your sigma is. You could do a motocraft but just check about comparability. Some coolants don’t mix well with others. 
 

https://www.fcsdchemicalsandlubricants.com/quickref/coolantsEN.pdf

 

[Randy Flowers]

My car is a 2020 310R (Ford Sigma engine). 

Here is the recommended coolant (and the only coolant listed at the Caterham parts site), but it is currently out of stock...

https://caterhamparts.co.uk/158-coolant

 

The coolant is due to be flushed (car is 4 years old), so we could use a totally new coolant and not need to worry about mixing it with whatever is in there now.  I would strongly prefer something that I can either order easily on Amazon or get at the local Auto parts store in Oregon.  Just want to know which exact coolant that I can get in the USA easily going forward.

I can get this kind of Motul 50/50 coolant, is it completely fine going forward, especially if we flush the coolant and don't mix it with whatever kind of coolant is currently in the system?

 

https://www.amazon.com/Motul-109533-Motocool-Expert-1lt/dp/B08DTZD9LJ/ref=asc_df_B08DTZD9LJ/?tag=hyprod-20&linkCode=df0&hvadid=692875362841&hvpos=&hvnetw=g&hvrand=14298195301580668345&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9033094&hvtargid=pla-2281435177618&psc=1&mcid=663da278f7a3304d9a6bd6e48026d3d1&hvocijid=14298195301580668345-B08DTZD9LJ-&hvexpln=73

 

Randy

[Randy Flowers]

If we flush the entire system, how many liters of coolant is needed when refilling the system?

 

[CBuff]

My 2023 Duratec was filled with motocraft yellow I believe. It is easily available. If you are doing a replacement / flush I think you’re pretty good with any of their products. It’s just mixing that can be tricky.  

[panamericano]

You just need to drive a ways to the friend?  Then it will be flushed to be refilled with new coolant?  Why not just top off with water for this excursion?

[hyper7]

https://caterhamcars.com/assets/Documents/Owner-Downloads/Owners-Handbook-All-Models_2023_ED1.2.pdf

 

page 23 - says you need between 4-5.5L depending on which motor/options.  it also only lists the MOTUL stuff as the "correct" fluid, but i'm in the same boat, seems like that isn't available anywhere. i'm going with the motorcraft yellow for mine. 

[Randy Flowers]

I called and talked to Caterham Parts in the UK a few days ago and he said to not mix coolant types, and that it was OK to just put distilled water in it to top it back up.  He also said for putting a new coolant type in, any OAT type 50/50 would be good going forward. 

 

I put in 2.5 cups of distilled water today and saw no leaks at all when running the Seven for a bit.  I am taking it over to my mechanic's house tomorrow to check it out better and figure out why I lost a few cups of fluid.

 

How about this for the new coolant to use when we do a coolant flush in a few months (Motorcraft Yellow 50/50 with POAT tech)?

https://www.oreillyauto.com/detail/c/motorcraft/oil--chemicals---fluids/antifreeze/antifreeze---coolant---vehicle-specific/df3a6469dc0a/motorcraft-1-gallon-yellow-50-50-antifreeze-coolant/mot0/vc13dlg?pos=56

[CBuff]

I found this helpful

[MV8]

I'd flush then use green conventional designed for older vehicles. If there is inadequate cooling, short of changing hardware, I'd use the gold.

https://www.oreillyauto.com/detail/c/o-reilly/oil--chemicals---fluids/antifreeze/antifreeze---coolant---vehicle-specific/df3a6469dc0a/o-reilly-1-gallon-green-50-50-antifreeze-coolant/afz0/gal5050?pos=1

https://www.autozone.com/antifreeze-radiator-additives-and-windshield-wash-fluid/antifreeze-coolant/p/shoppro-engine-coolant-antifreeze-green-concentrate/540722_0_0?searchText=coolant

Edited September 19, 2024 by MV8

[dstb]

I have a similar issue here with a recently purchased 2014 360.  The coolant currently in the system is clearly green.  The manual specifically calls for red.  The MOTUL previously mentioned is an OAT (organic acid) coolant which is quite a bit different than the standard green coolant.  One would think just flush out the green and replace with the proper red but I have read some horror stories (not sure how true) of the coolant system getting gummed up even AFTER a flush.  Possibly some green still remains in the radiator or hoses.  My car tends to run a bit on the cool side when I get it moving.  Around 60 rather than 80+.  Not sure if this has anything to do with it.  If anyone has any experience with changing to a red OAT coolant from another kind please chime in.  Thanks.     

[MV8]

I don't see any coolant issue. Green is readily available and the orielly's is one of the best green coolants. In switching to the recommended coolant, you may create one. A switch involves thorough flushing with water; not just pouring out one then pouring in the other.

 

That is too cool. First thing to do is determine if the thermostat is installed and working properly.

[dstb]

Thanks.  Haven't had a chance to get it into service and don't even know where that will be yet.  Caterhams aren't exactly a specialization of many shops around here.  My knowledge is limited but I'll have that looked at.  Gauge accuracy could also be an issue.  Already ran it out of gas in my driveway when it was reading around a quarter tank.  First time in my life I've done that but also my first British car. 

[MV8]

Do a "Cars and Coffee" or car show in Ellijay or Dahlonega and ask around for competent local support.

 

Running out of fuel can ruin a fuel pump but I would not change it prematurely.

This may improve the fuel gauge accuracy:

 

[dstb]

Yeah it wasn't the best but the car seems to be behaving the same before and after the incident.  We have a local car club where I have done cars and coffee with my Porsche.  The problem is there are probably not two models the same that show up except Corvettes.  And even on boards like this and others there are many opinions for the same issue.

 

On the coolant I realize the system would need to be very well flushed to avoid any negative interacting with a switch from green to red.  More research is needed here.  Next is an oil change.  I am running too low a pressure at hot idle and believe it is probably the lower weight oil used at most oil change shops from previous owner.  Going to bring it up to manual spec.  

[ralph]

Just adding my $0.02 re:coolant here, in lieu of a new thread.  I put a 420R together a couple years ago, and decided to cheap out on coolant, expecting to swap it in a year, and the cheapest I found was green.  I missed the fine print about coolant types, and later noticed that the convenient color coding does not obviate the need to read the fine print -- i.e. "blue" isn't silicate-free glycol in all cases (i.e. US/UK/EU/JAPAC coolant color standards are not necessarily the same). 

 

Anyway, long story short, I put in conventional/legacy green stuff, and just got through fixing that problem with a series of flushes (to @MV8 point that you can't just drain and refill, unless you have a gantry crane that can hang the car upside down or something).  Flushing ritual went a bit like this:  drained what i could (with rear of the car elevated), added prestone clean/flush w/distilled water and ran for 10min, then went through a series of 5 drains and refills with just distilled water, elevating the rear at drain time, and the front a fill time -- basically, until what comes out of the car is mostly clear. 

 

Attached is a pic of the build-up in my heater circuit after just 18mo/5kmi, and the sticker on the reservoir that very clearly indicates that putting green things in there (esp. mixing) is a no-no, and RTFM is advised.

 

Final fill was the new Ford *Yellow* (P-OAT) concentrate diluted to ~40% plus 5oz of Redline Water Wetter.  Would love opinions from the readership here on that fill formula...not thrilled with the idea of spending another day dancing around the car with water bottles, but less thrilled about having my radiator shit itself.  Is Ford's yellow/P-OAT the new hotness coolness?  What do folks run at the track - non-glycol stuff?...just distilled water and water wetter?...

 

 

[dstb]

Thanks for the info.  Unfortunately I can't answer your questions because I haven't done anything yet except acquire a number of bottles of Motul Auto Cool Optimal red coolant which I will use when the time comes.  Let us know how the car runs before and after and if you have any issues. 

[KnifeySpoony]

In my 420R I'm running Zerex G05 (since the beginning). Run it at the track too - it's not like bike trackays where coolant is banned. BTW running the proper coolant is no guarantee of a healthy radiator. The radiators on our cars are prone to failure/leaks. My first rad only lasted about 3k miles. When I put the second one on, I changed the upper hose from that rigid rubber hose to a more flexible silicone hose, as a few blatchatters have done (using a 620R top hose). Theory being that the radiator is under stress and flexing itself to failure. So far so good.

[MV8]

11 hours ago, ralph said:

Just adding my $0.02 re:coolant here, in lieu of a new thread.  I put a 420R together a couple years ago, and decided to cheap out on coolant, expecting to swap it in a year, and the cheapest I found was green.  I missed the fine print about coolant types, and later noticed that the convenient color coding does not obviate the need to read the fine print -- i.e. "blue" isn't silicate-free glycol in all cases (i.e. US/UK/EU/JAPAC coolant color standards are not necessarily the same). 

 

Anyway, long story short, I put in conventional/legacy green stuff, and just got through fixing that problem with a series of flushes (to @MV8 point that you can't just drain and refill, unless you have a gantry crane that can hang the car upside down or something).  Flushing ritual went a bit like this:  drained what i could (with rear of the car elevated), added prestone clean/flush w/distilled water and ran for 10min, then went through a series of 5 drains and refills with just distilled water, elevating the rear at drain time, and the front a fill time -- basically, until what comes out of the car is mostly clear. 

 

Attached is a pic of the build-up in my heater circuit after just 18mo/5kmi, and the sticker on the reservoir that very clearly indicates that putting green things in there (esp. mixing) is a no-no, and RTFM is advised.

 

Final fill was the new Ford *Yellow* (P-OAT) concentrate diluted to ~40% plus 5oz of Redline Water Wetter.  Would love opinions from the readership here on that fill formula...not thrilled with the idea of spending another day dancing around the car with water bottles, but less thrilled about having my radiator shit itself.  Is Ford's yellow/P-OAT the new hotness coolness?  What do folks run at the track - non-glycol stuff?...just distilled water and water wetter?...

 

 

Thanks for sharing, but a conclusion that green coolant is not compatible due to what was found in a fitting lip is weak at best.  Due to residual oils and chemicals from manufacturing processes and anything that may have migrated into all the components before installation, a new build should be flushed before adding coolant. One example is the hose in your pic. It is made by wrapping uncured, reinforced silicone sheets around a mandrel that is prelubed for easier removal after heating to cure the silicone and may not be adequately flushed. Residual flux from soldering or brazing is another possibility.    

The label on the tank indicates the recommendation is to use their red and not to mix coolants.

All green is not the same. If it were, I would not have made recommendations. The cheapest "green" is likely Supertech at Walmart and I do not recommend it.

Ratios vary as well. I've found the cheaper premix to be very weak and cheap concentrate to be weaker as well for more profit, similar to the subtle shrinking of food packaging. It is on the installer to check and adjust the ratio; not to rely on the label on the bottle.

 

[Croc]

On 2/8/2025 at 8:28 AM, MV8 said:

Due to residual oils and chemicals from manufacturing processes and anything that may have migrated into all the components before installation, a new build should be flushed before adding coolant. One example is the hose in your pic. It is made by wrapping uncured, reinforced silicone sheets around a mandrel that is prelubed for easier removal after heating to cure the silicone and may not be adequately flushed. Residual flux from soldering or brazing is another possibility.   

 

Not enough is made of this important point.  Always flush new builds to remove production residues and always flush between different types of coolants.