THE INTERNATIONAL JAGUAR 'S'-TYPE REGISTER FORUM

Thanks for the info my S type has OAT in at present and it looks good colour wise.

Dave ~ I've had both OAT & HOAT coolants in my car already depending what I had to hand during the build. I'm not here to promote my old company's products. I don't mind if you use Prestone etc.

At present I have the following HOAT product in the system because it's approved for my Benz as well.

https://hallmarkoil.com/wp-content/uplo ... ne-XLC.pdf

Out of interest the Benz version of this product has been in my low mileage (31 thousand miles) Benz quadcam V6 engine for 10 years without change & is still clear & bright. Will easily go 15 years as long as I don't spring a leak.

I note since my retirement the rotters in the industry have steadily reduced recommended mileage from 10 years, to 8 & now to 5 years to try & sell more product. e.g. I note that Prestone's European literature still claims 10 years whereas their US literature states 5.

As long as the product remains clear & bright the non depleting inhibitors are doing their job. In totally captive systems slight evaporative loss can be topped up with deionised water as the inhibitors don't deplete. The only reason I recommend top up with premix is to ensure that glycol concentration does not drop in cold climates where antifreeze properties must be maintained and the user might not be sure of the mechanism of coolant loss.

Thank's once again GLyn for you comprehensive explanation regarding anti freeze & coolant. As a matter of interest what have you put into your S type OAT or HOAT and what make is the product ?.
Cheers
Dave J.

Thanks very much, Glyn.

Hi Orlando ~ Our company was the pioneer of extended life coolant using carboxylate and other inhibitor technology & holds more patents than any other. We also have more million mile tests under our belt than any other with just about every OEM on the planet including other than automotive applications. There is more nonsense spoken on the internet about coolants than just about any other oil company products. They are today universal in their use. Cooling systems are healthier than ever & less expended glycol is polluting our planet due to long service life.

There is nothing in the metallurgy, componentry or design of our Jaguar cooling systems that would make ELC's anything but absolutely ideal for their protection.

I am personally delighted that I'm running long life coolant in my S Type so that I can maintain the system in as new condition. One of the reasons I'm trying to eliminate coolant loss in shut down, heat soak conditions.

There are some that wish to get stuck in the past as though the past is somehow better. We should by all means learn from the past but technology marches on for the better. These products are tried & proven & mature. Fortunately most OEM's today consider lubricants, coolants etc. as a design component of the vehicle.

Interestingly I have been re reading one of my old Aston Martin books & the knowledgeable scribe points out that many of the issues experienced by Aston with the Watson/WO Bentley for Lagonda & Tadek Marek designed engines are simply of no consequence with modern oil technology ~ Amen!

Glyn, do you think there's anything in the multitude of scare stories online about the use of OAT in classics?

Also recommend you use modern OAT or HOAT long life coolant & you will suffer zero depositing, sludging, scaling or gel formation. Even radiator solder will remain bright & coolant clear & bright over extended periods.

We unfortunately don't have totally captive systems, but in a totally captive system, companies like Benz now go 15 years without coolant change.

With our open systems 5 years would probably be a sensible change period but with constant top up could go longer. e.g. 8 years

Your only possible negative might be that the water jacket might be a little fouled up due to negligence in the past requiring multiple flushes for good effect. If one is starting with a rebuilt clean engine/radiator these coolants will maintain performance for a very long time.

The only caveats ~ don't mix different coolants, always top up with premix at the desired ratio (most people don't walk around with refractometers to check concentration for anti freeze properties). Change if the coolant is not clear & bright.

As you may want to drain the system frequently in the future, it may be worth considering fitting an armoured drain pipe and repositioning the drain tap/ blank under the dynamo area. The additional pipe can be clipped to the sump set screws. This arrangement encourages more frequent flushing being far easier to drain the cylinder block than fighting to reach the block tap that is often blocked.

If you are having either a re-cored or new radiator you may also find it worthwhile having extra threaded ports in the header tank. These make pressure testing under running conditions very easy and also permit an additional point to return the coolant from the rear of the engine if required.

Norman.

This is the construction of that coolant drain tap ~ C2354. (available from XK's Unlimited.)

Agree with Orlando ~ smother it with penetrating oil & let it soak for a few days. Then try & knock the pivot shaft up against the spring & you will hopefully break the seizure.

Apply heat as a last resort.

Otherwise replace.

San Jose Scott wrote: ↑Wed Jul 31, 2019 5:46 am Any suggestions on how to un-freeze the tap? If I want to replace it is there an easy way to remove it or do I need to pull the exhaust manifold?

Well, you could try WD40 or penetrating oil, but it's probably easiest to just replace it, although that's easy for me to say - I've never done it! I don't think you would have to remove the exhaust manifold, but, I agree, it is awkward to get at. The position doubtless works for earlier Jaguars which don't have the swept back exhaust manifolds.

My parts catalogue says the part number is C31616, but SNGB offers a drain plug for that part, which I guess would work - and better for flushing:


They do offer a tap as well under part number C2354, which their website says fits the S-type: