Ben, you are correct. The core is a single plane and air blend doors are used to vary the temp. If rear air system is installed, then it is broken off into two separate cores, one in the front, and one in the rear.

 

What I'd like to know is where the silt comes from that clogs the heater matrix. Is it corrosion from the aluminium that the heads and block are made of ? This begs the question as to whether the diesel cars suffer this syndrome, as these only have aluminium cylinder heads, the block is cast iron.

Final thought is - surely all this OAT anti-freeze technology was supposed to stop all this ?

 

Silicates causes cavitation in aluminum. There are steel liners, even though the block is aluminum. Rubber hoses shed internally due to age. Improper maintenance can add water that is not distilled which causes electrolysis and shedding of material, as well as growth of mineral and hard water deposits. Mixture of different additives, mixture of different types of coolant can cause gelling. There are many reasons why cooling systems need to be maintained. The real fix is regular maintenance, including hose replacement and tree replacement.

 

Not used my car for about a week, so today, as it's -3 outside, and the frost hasn't lifted all day, i thought i would start it up and run it up to temp, I let it run for maybe 15 mins, then i went out and sat in it, engine temp was 72, turned on the heat and it was look-warm, So I brought the revs up to 1500, and the temp went up to 90, no further, turned the heating on again, still look-warm. You now have me wondering if it's just because it's so cold outside and the car isn't being driven, or if I also now have a blockage in my heater. on the plus side the heated seat had to be turned off as my **** was burning, LOL.

Been looking at Evans waterless coolant, it's not cheap at £60 a gallon.
Evans Power Cool 180 Waterless Coolant 5Ltr

Evans Power Cool 180 is the coolant of choice for many professional racing teams and performance car specialists. For use in all performance car engines primarily fabricated from aluminium, plus some steel and copper components.
Conversion from a water-based coolant to Evans is a straight forward process that can be undertaken by anyone with some basic experience in engine mechanics.
The primary objective of converting to Evans Waterless Engine Coolant is to eliminate all of the problems associated to water:
Eliminates Overheating
Evans Waterless Coolants have a boiling point above 180°C and will not vaporise, thus eliminating overheating, boil-over and after-boil.
Reduces Pressure
Evans Waterless Coolants generate very low vapour pressures reducing strain on engine hoses and cooling system components.
Prevents Corrosion
Water promotes corrosion via oxidation and electrolysis. Evans Waterless Coolants contain no oxygen and are virtually non-conductive effectively preventing corrosion.
Maximise BHP
Evans Waterless Coolants eliminate pre-ignition and detonation caused by overheating - thus increasing combustion efficiency and delivering more power.
Stops Erosion
Evans Waterless Coolants stop cavitation and eliminate liner and cooling pump erosion.
Freeze Protection
Evans Waterless Coolants freeze below -40ºC
Non-Toxic
Evans Waterless Coolants are proven to be Non-Toxic. Standard anti-freeze is toxic and known to kill pets.
If the engine to be converted is currently filled with a water-based coolant an important part of a good installation is using Evans Prep Fluid. Prep Fluid is specifically formulated to purge remaining water-based antifreeze from the system after initial drain.
The prep fluid is £40 a gallon, and I think a 4.2 V8 SC would need 2 gallons of each, so that's about £200. But it sounds like it would be a good way to go, only thing is, yuo would have to make sure no one doing a service drained it, or topped it up with standard coolant, or water.

 

Interesting point. If you look at the coolant change interval on the service sheets for the petrol (gasoline) and diesel engines ...

Petrol 5 yrs or 150,000 miles (240,000 kms)

Diesel 10 yrs or 150,000 miles

 

Yes, from another thread, I'm also reading it wrong:


And from Tech "Brutal": ok again I answer same issue. did he blow it out first? I have cut many cores open(theres only one) and the drivers side portion is on the end loop and gets plugged with sediment from the cooling system(never found sand). If its been flushed and blown out, you need to replace the core..This issue comes up EVERY yr when it starts to get cold and people use the heater again after a summer of non use.

https://www.jaguarforums.com/forum/x...er-core-85672/

Sorry gentlemen, for the misleading info.

 

Hi Ben

I have seen your posts on the UK forum and I know you are based in Telford where I have driven past many times on my way from Kent to North Wales.

I suggest the following:

The blockage MAY be aluminium hydroxide.

We know aluminium hydroxide is white, gelatinous, sticky and crystallises

with time.

The deposit has been reported to be yellowish-this may be due to

contamination.

No need for a pump etc IMO remove matrix from the car by removing

the glove box which doesn't look very difficult.

Sodium hydroxide will precipitate aluminium in solution as aluminium

hydroxide but if you continue to raise the ph it will redissolve.

I am not sure how the flow is arranged in a matrix but you will

need to ensure that the caustic solution gets to the blockage if you see

what I mean hence clamp the matrix with the connections facing up.

The problem is that caustic will dissolve aluminium if it is too strong.

I don't know how you decide if the blockage has been removed or not

since if you flush with water I believe it will appear to run 'full bore' when

blocked.

The matrix could be immersed in warm water to increase the rate of

reaction. Rate of reaction doubles with every 10 deg C rise.

Robert

 

Very interesting thank you. Not long after I bought my car I had noticed some residue on the top of the level indicator in the coolant expansion tank exactly the same as you describe the aluminium hydroxide to be.

The previous link showing the cut open of the matrix shows how bad the internals must be, and seems doubtful that a flush would get rid of that mess very easily.

From what I read the matrix removal is quite a difficult job, even after removing the glovebox (which I have previously done for another reason), so the thought of being able to flush the matrix properly just via the pipes in the engine bay was quite tempting! I also have the same issue with my rear heat in the 4 zone climate.

If going to the trouble of removing the matrix I think I would just swap with a new one to guarantee it working. But, it would be interesting to do some experiments with the old one to see if a proper flush is possible. As you say, it’s difficult to know whether it’s been successful as the flow seems the same whether it’s blocked or not, I imagine circulating hot water and viewing with a thermal camera or thermometer would be the best ways to check.


Ben

 

What is the matrix made of ? Is it aluminium ?

 

The problem is that the coolant flow can be the same, but as it's going through a much smaller part of the matrix, the ability to transfer the heat into the air flow from the fan is lowered. It's the same with the main radiator where this gets partially blocked; the hot coolant gets through, but doesn't give up enough heat so on re-entry to the engine its not cool enough to accept enough heat from the engine thus it overheats.

 

Yup, but depending on vendor for replacement, it could be either aluminum or brass.

 

I have lowered the glove box in the past and then you can see the end of

the matrix and once you have disconnected the hoses I assume the

matrix just slides out. I hasten to add that I have not needed to do it myself.

The problem will come I think when re connecting the hoses because the

clips etc look pathetic to me!

 

Found this thread in the archive https://www.jaguarforums.com/forum/x...lation-130143/

Ben

 

WOW, yeah now that's a revelation, some serious blockage in there. The full flow from a " flushed" matrix will be down to the way the matrix is constructed, it's basically a series of pipes with a reservoir either side, so fluid fills it and flows through all the pipes at the same time, so if one is blocked the fluid still flows through the clear pipes, but not the blocked pipes, so really what it's doing is reducing the surface area of the matrix, the more pipes that are blocked , the less surface area there is to heat up, and as the matrix will be fitted either standing up or angled, then it stands to reason that gravity will have an effect on just how the blockage develops, i'e from the bottom up, which means the more pipes that are blocked the less heat there will be to blow through, and your blower will cool it down quicker. hence less overall heat, you may find that not using the heater at all until the engine is at full operating temp, will produce a good initial heat from the unit, but the heat will die away quite quickly.

As for dissolving the "sediment", if you don't then flush the system properly, then that sediment is only held in suspension, until it solidifies again and settles right back where it started.

And I do agree that if it came to the stage where I had removed the matrix to flush it out, then, for £130 or so, and a pretty much guaranteed 10 years trouble free, I would def just replace it with a new matrix. But working from the ground up as it were, I would attempt a flush with everything in situ first, It may do the trick initially, and at the very least get you through the winter, but come summer I would be then looking at a long term fix.