I'm about to attempt to drain and fill my coolant myself. I have never done this on any car could someone provide me detailed instructions on this process for a 1992 vdp. I don't know where to find the drain plug. Could you recommend the best antifreeze or will that prediluted 5050 work? Will I need more that one? Thanks in advance? Also the reason I'm doing this is because my car never gets warm anymore it chills between c and n byhut a lot closer to c but on warm days it will get warm but then why do I need the heater

 

Sounds like you need a new thermostat there mate! BTW, go easy on the thermostat housing bolts, the snap very easily. Your gas mileage will improve too if you fit a new (working!) one.

To drain the system, undo the (plastic) radiator drain plug - as I remember it's located at the bottom of the rad, over on the passenger side. When I re-filled mine I was concerned about getting an air lock but that wasn't an issue ...I just kept the header tank open and topped it up as necessary as the engine warmed up.

If you can't undo the drain plug (should be easy though) you could always release the bottom hose from the rad, driver's side.

I plumped for straight anti-freeze and did the dilution myself, but 50/50 would be ok too, just make sure it says it's safe for aluminum engines - however most brands today conform to that standard I should think ..maybe some other member has more precise specs for anti-freeze, I just went for the first stuff that said it was ok for aluminum.

Oh and for the amount - good idea to buy more than you need and return the extras after you get through with the job. I used the non diluted stuff and I think I used 2 gallon bottles, however memory ain't what it used to be, maybe google the coolant capacity or look in Haynes if you have it?

all the best

Larry

 

Here's some more info from the archive

https://www.jaguarforums.com/forum/x...en-plas-84277/

Larry

 

Hi Donald,

It sounds like your coolant thermostat may be stuck open, preventing the engine from reaching operating temperature. The large photos are still not working at Jag-Lovers, but you can see my thumbnails and descriptions here:

Jaguar XJ40 Coolant Thermostat Replacement

The radiator drain plug is somewhere along the lower edge of the radiator but I can't recall which side. Hopefully someone else will remember.

Thermostat failure is very common, but another issue that can affect your heat is the heater control valve. If your '92 is equipped with one, it looks like this:




As far as coolant goes, any good conventional green ethylene glycol phosphate-free coolant will be fine. You will typically save money by purchasing the concentrated coolant and mixing it 50/50 with distilled water, rather than purchasing the pre-mixed coolant that already has water added (I'll mention another reason to go with the concentrate later). I think you will need a couple of gallons of concentrated coolant.

Professional shops may use special hose fittings and equipment to back-flush the cooling system, vacuum-powered refill systems, etc., but you can do a pretty good job of flushing the system yourself, with a few gallons of distilled water. Here's one DIY method that avoids the need to access the block drain plug (which is under the exhaust manifold and hard to access):

1. Drain as much coolant as possible from the radiator drain plug or disconnect the lower radiator hose. Collect the coolant in a large container, like a wide-mouth catch pan:


Ethylene glycol coolant is toxic, but its sweet smell and taste attract children and animals, so it must be disposed of promptly and properly. Check your local regulations.

2. Tighten the drain plug or reattach the lower radiator hose.

3 Add distilled water to the coolant reservoir until it is full. Leave the cap off and start the engine. As the coolant level declines, continue to add distilled water until the reservoir remains full. Install the reservoir cap.

4. Run the engine to full operating temperature and then an additional 5 or 10 minutes. Shut off the engine.

5. Draining via the radiator drain plug leaves the system about half full of old coolant-water mix. To remove the remaining old coolant, repeat steps 1 through 4 two or three additional times.

6. At this point, the system will be full of distilled water, with only dilute traces of old coolant. If you were to drain the system again (leaving it half full of distilled water), then add a 50/50 mix of coolant and distilled water, the resulting coolant concentration would be something like 25/75. So instead, after draining the system one more time, add straight concentrated coolant until the bottom surface of the reservoir remains covered with coolant. Leave the remaining volume of the reservoir empty for final adjustments.

7. Leave the reservoir cap off and run the engine. Watch the coolant level in the reservoir and add coolant as necessary to keep the bottom surface of the reservoir covered. When the coolant level is stabilized at the bottom of the reservoir, install the cap and run the engine for 10 minutes.

8. Shut off the engine and allow to cool enough to safely remove the reservoir cap.

9. Use an inexpensive anti-freeze hydrometer to check the freeze- and boiling-points of the coolant-water mix:



Typically, a 50/50 mix of ethylene glycol and water will provide a freezing point of around -35F and a boiling point of around 223F. If the tester shows that your coolant mix has a higher freezing point, you can add more concentrated coolant to the reservoir. Run the engine for 10 minutes and test the concentration again. Add either straight coolant, straight distilled water, or a 50/50 mix as appropriate until the reservoir is full.

I hope this all makes sense.

Cheers,

Don

 

One other point as has been mentioned, IF your car has the heater cut off valve turn the heat control to full heat to ensure the heater matrix is in the circuit.
For the initial flush I would probably use straight tap water rather than purchasing distilled water, and definatly go with the concentrate, and keep the unused liquid, you are going to need it eventually.

 

So I should change the thermostat before flinching the fluid or would it be fine to change the fluid nowand the thermostat on friday

 

Some coolant will spill out when you disconnect the thermostat housing, so to avoid wasting new coolant I would recommend draining the old coolant, then either flushing the system or replacing the thermostat in either order, then refilling with new coolant.

Rob's suggestion of using tap water for the initial fill is probably fine in many areas, but since some of the tap water is going to remain in your final coolant-water mixture (unless you follow up with at least 3 or 4 pure distilled water flushes, which will undermine any potential savings), it would be ill-advised to use tap water if you live in an area with hard water or water with a high mineral content. In our area, distilled water is available in every grocery store for less than USD $1.50 per gallon, so I use it exclusively to avoid introducing any unnecessary minerals into cooling systems.

Cheers,

Don

 

Fair comment Don, Being in NZ for so long I had forgotten about the problems that can be had with water. Thinking back I can remember the build up in the kettle (jug) when I lived in Birmingham., I had to purchase 4 litres of demineralised water yesterday due to the XJR springing a leak cost me $nz9.00

 

One other issue I should have mentioned is that today there are several varieties of antifreeze available, and some of them must not be mixed with others for various reasons, including the possibility of the formation of sludge or accelerated corrosion. As I mentioned, Jaguar specified ethylene glycol (EG)-based antifreeze that is phosphate free. Today EG antifreeze is categorized as using Inorganic Acid Technology (IAT). You can purchase conventional green EG antifreeze at most auto parts stores either under the store brand or national brands like Zerex or Peak.

In a system designed for IAT coolant, it is important to not use an Extended Life Organic Acid Technology (OAT) antifreeze (based on propylene glycol (PG) and typically dyed orange, red or pink) such as Dex-Cool, used in many GM and Ford vehicles and later Jaguars (X100 and X308 onward); or a Hybrid Organic Acid Technology (HOAT) antifreeze (also PG-based) as used in Chryslers (also dyed red or orange, or sometimes clear); or variations of these with or without silicates or phosphates as used in Asian and European cars (typically dyed blue, pink, red, yellow, etc.). Despite the claims of third-party antifreeze manufacturers, many auto manufacturers warn that IAT, OAT and HOAT coolants should never be mixed.

Prestone's ubiquitous yellow-dyed "universal" antifreeze is EG based, but I do not know if its corrosion inhibitors and other additives are fully-compatible with traditional green EG, so I use green EG in all vehicles that call for it. As an added benefit, conventional green EG is often less expensive than Prestone yellow or OAT or HOAT antifreeze.

Cheers,

Don

 

I changed the thermostat and coolant everything is back to normal the ole thermostat was clearly stuck open. Thanks for all your help those links provided were great tools in getting this done.