Admin …
I cannot find a cooling and heating system section in your spanner sections to post this up in…???
Any way for the I’ll informed on the “BROWN RAD OF DEATH”…
Copy and paste into your search bars…
http://www.mazdamenders.net/forum/viewtopic.php?f=219&t=6967
Know the correct facts before spreading ear say…
Stop worrying and stop wasting money until it is needed to be used…
Drive safe and enjoy your roadsters.
M-m
Yes, agree with this. That olive green/brown colour seems to manifest itself quite quickly with the original radiators.
Although most rads that expire are that colour it is far from certain that a rad that colour is about to expire.
Our Eunos rad was always olive green as old but only expired after a further 8 years of ownership and when I interfered with it doing a cambelt change.
I have had a lot more experience, particularly on the MK1 of partially blocked radiators where the narrow tubes become choked and the flow rate reduced to the point that the rad is useless.
It happened on my MK1 that was regularly serviced so definitely worth keeping an eye on the flow rate of an old radiator rather than worrying about a plastic tank split/burst that probably will not happen any time soon.
MM - cooling is one of the subjects covered by ‘engine and transmission’
Yes, as the top tank heat cycles, the dye used by Mazda (Denso) will change. This is not a change deliberately by Denso, and so should not be necessarily used as an indicator to change the radiator.
As the radiator ages, in some cases, a whitening of the radiator can be noticed. In most other cases, the radiator top will start to separate, or stress fractures appear around the radiator cap. These stress fractures may not be immediately apparent with the radiator in-situ. When the car is hot, they may open a little, causing loss of coolant. Leaking coolant can track back along the top and pool in the far corners. On 1.8 models, where there is a sealing foam strip, the foam might be wet to touch.
In cases where there is intrinsic overpressurisation of the system, the radiator may dramatically open up, because it is weakened. However, all water-based cooling systems will pressurise. Plastic that is weakened will have a greater likelihood of failing than a newer radiator. Conversion to a Waterless coolant, recommended by Comber Racing and others, removes or reduces this risk, as waterless systems do not pressurise (offering improved efficiency, due to no cavitation, or microbubbles).
In this example, a 1996 radiator developed leakage due to hairline fractures. The coolant was in excellent condition, and the radiator clean.
The new radiator is a Nipparts item.
Upon removal, on the engine side, a fracture was noted
A HOAT-based antifreeze is good for 5 years before changing. Waterless coolants (I use Evans Powercool 180) have a longer service life. They are a little more money than regular antifreeze, and the conversion is expensive, due to the need to clean the system of water first (clean out costs £50, but garages can reuse the cleaner, so its possible to save a bit of money by having two cars done). The coolant itself is about £50-60. Lack of pressurization means that if there is a hose failure, there is no chance of a catastrophic loss of coolant (but lack of pressurization means the hoses now won’t split). No water means no corrosion, so the radiator won’t block up because you have been topping off with tap water. No pressurisation means no loss of coolant because the radiator cap is old.
Water based systems, with standard caps, pressurise to about 16PSI, before the cap opens up into the expansion tank. Modified cars may have higher pressure caps fitted. Pressurisation is essential with water, because you need to get it to boil at over 100 Celcius. If it boils at 100 Celcius, cavitation occurs (bubbles) where the water contacts the head, leading to hot spots, affecting efficiency and shortening engine life. Manufacturers will state that these microbubbles can exert 60,000 PSI of pressure, and will pit the metal.
There is a measurable benefit in track times, because of the improved cooling efficiency (see MCR). It is essential that the cooling system is in good condition (esp. the water pump).
If there is an underlying fault in the engine causing over pressurisation, replacing the radiator with a larger capacity aluminium radiator may just mask the issue.
The NAs are getting to an age now when there can’t be hard and fast rules when or how a radiator may fail. Many are now onto their second radiator now, in many cases, not a Denso radiator. We have no idea how these radiators will do over a 10-15 year service life.
On the other hand, if you are looking at a MX5 that is approaching 30 years old with an original radiator, it might be cost effective to carry out preventative maintenance now, and replace the radiator while original Denso items are still available (I wouldn’t bank on that in 5 years time, I expect original parts to very quickly disappear over the next few years). Or start storing parts. The radiator sees a lot of abuse, and its always preferable to replace it at a time of your choosing, rather than having a car pouring steam at the roadside, leaving you with the worry if the engine was cooked (the B6/BP engine though is quite resilient). I changed these a couple of times, its an easy enough job.
Now i have just gone to post on the other abuot this being locked up so you cannot post on it, and thats locked up …whats going on in here???
Any way this was my reply on the now locked up thread…
A polite PM to inform about the intentions would of been nice, the post was posted to dismiss the wrong info and advice being past around as correct, which even owners in the national rally in the comps were hit with and caused unnecessary worry and concern to many that was not needed and should never of happened plus they were knocked points off for the “BROWN RAD OF DEATH” which was wrong also.
there are loads of myths that are posted up as correct which to be dead honest to the chaps that know these roadsters inside out and worked on that many we can do it blind folded, we laugh in the back ground at some of the guesses,and misinformed info that is spread as fact from ear say etc, that really does not help anyone.
The mazda mx5 owners club UK on two face book is a prime example of bad advice and info being given as correct, it is very entertaining for us, because they will not listen anyway so not worth wasting time on,
That FB group by the way which is nothing what so ever to do with the MX-5 owners club which forum we are on is nothing what so ever to do with the club and a lot of members are joining thinking it is one and the same …it is not, so if you are in this joke group, remove yourself ,it is a joke of a group and not what you think.
So as most of the stuff i but from total frustration from hearing rubbish posted and shared as correct info i built the guide to put fellow owners at rest to stop worrying to the whispers of doom and gloom that are incorrect, to share it with you you , because just like you lot i have a budget for my roadsters,i do not want to spend if not needed but keep the cars correct, and i am lucky to have been around cars a long time on the spanner side, fault finding, repairing…upgrading…mending and been around the mazda roadsters from day one as i moved on from classics, and built up a wide knowledge of theses ace little roadsters that Mazda built for us to play with ,and i share this info freely so you lot don’t get ripped off, because if i personally did not know the knowledge i have it would happen to me, so i make sure it will not happen to me or you.
Anyway time to start work.
It is going to be a good week weather wise, slight chill but the heaters in these things are great.
Drive safe
M-m