Thanks ICS...

Its like,,, yesterday things were working well. Did some work, and today they are not... I don't think I need new parts.

It sounds like my ideas or belief that ratios of coolant to water and water to coolant wouldn't produce what I'm seeing. It sounds like I haven't bleed the system correctly. I thought I had. Back to the drawing board!!!

Thanks for all of the amazing information (as usual) in your reply!

If there were numbers instead of just the word normal. You could eventually educate yourself that a blend of Anti Freeze and water ( please tell me it was distilled water* and not tap water). Is better for your cars health. 180- 210 is ideal. Less than 160 won’t evaporate the condensation that happen when a hot engine cools off nor will it get rid of the acid that is formed from the dissimilar metals in your engine.
Slightly hotter than midway helps the engine. If you wanted to get a million miles out of your engine you probably could but you would have to never shut it off. That heat is good because less than 160 degrees is too cool to properly evaporate the condensation and acids that build up in the oil. 180- 210 is best. Convince yourself, buy one of those infrared digital thermometers about $20 on Amazon. Now open the hood of your car when the temperature reads slightly over 1/2 way and aim it down at the lower Right radiator hose. That’s the actual temp of the coolant.
If you aim it at the top hose where it comes out of the engine ( and the temperature is measured) you’ll see the difference and that’s the amount of heat removed from the engine. Anything less than boiling is safe. Once boiling, air pockets form and wherever those are no heat is being removed. Above There is a chart that explains percent of coolant And pressure the actual point of boiling.

The hardest thing to do to your engine and any car is shut off the engine. That’s when heat soak gets it because there is no longer cool air and cool water flowing through. That heat soak pushes gaskets and hoses. If you leave the ignition on but shut the car off you can watch it happen.

In addition oil drains away from wear surfaces. So later when you start up the car you have bare metal on bare metal. Until the oil pump picks up oil from the pan and circulates it to every bearing and up into the cylinders. The location of the oil pressure pickup fools you into thinking you get oil right away. Located at the start of oil’s circulation through the engine it shows pressure long before bearings at the end of oil’s path get any oil.

*distilled water because you don’t want to put iron and all the chemicals in tap water into your engine Distilled is pure water free of impurities.

JJJ
It is far more likely that the engine is running at the same temps, but that you have a better or different connection t
from the temp sender than before you did all the work! If you are worried buy a 15 dollar temp gizmo and tape it to the top hose and see while you drive!.
https://www.ebay.co.uk/itm/Dual-Two-...0AAOSwgmJX1itg

I think that I did a bad job at burping and bleeding... I will do it over again. Im not so worried,,, until I need to be. And that ain't yet.

I know it's running hotter. I can feel it, smell it and now, unlike before, the second fan is running once I've been going a while almost all the time. When I shut the car off, it runs for a period. Wasn't doing that in most cases before. Not at all.

Guys... I was asking some general questions about coolant/antifreeze and water, the differences. And using what I was dealing with in my car,,, as an example.

Although I would LOVE it if this car lasted forever, I know that nothing does. I want it running right, or as close to right as possible - but I got 4 old cars and I ain't gunna go crazy with them. I will do the work,,, I love to actually,,, but am by no means a perfectionist, and I'll get it right eventually...

And, thanks for the magnificent explanations but I have to shut the car off, sometimes... I think...

If the car IS running hotter then there is a cause, and you must find it.
What have you done out of this list since you started out:

• radiator clean, test or renew
• fan clutch renew
• water pump belt / fan belt renew
• thermostat renew

Once all the coolant is out, there is always a chance of a blockage somewhere. I would get the car warming up and see (by placing your hand on the top hoses every 30 seconds, which one heats up first, and when both heated, which is running hotter. A jammed closed ot pertially opening thermostat is a possibility.

Finally, have you reconnected the heater hoses to the matrix pipes to the cabin? i mean, you have not bypassed the heater core have you?

Hi Man.

I have not bypassed the heater core. Heats working fine.

If by since I started out you mean since the BEGINNING beginning,,,,, ? I've replaced belt(s), thermostats, water pump, hoses, just replaced the yellow fan with the black denso fan, coolant... Until I did the work I did last week she was running NICE and COOL. Always. Mind you, it wasn't 90 degrees here before the last few days.

From the quote above, in red, are you saying that draining the coolant may have caused a blockage? Interesting.

Last week,,,,, I did cam cover gasket/seal, sealed an oil leak, and new intake gaskets and,,,, new hoses to the heater core at the BACK of the engine, since access was easy... water/coolant WAS spilled... No big deal... Not nearly all.

After the work, she fired right up,,, I think I made a MISTAKE in not properly bleeding the system. And I will check in that. Friday.... I think there is a good possibility THAT is my problem. Except new hoses,,, nothing is different than before I did this work.

If draining and taking another shot at bleeding the system and adjustment of the ratio of coolant to H2O, I'll report back. But, I have a feeling that will sort things out.

I sound like a broken record but if you have a Lucas distributor have you oiled your distributor? It’s in the owners manual and also the Kirby Palm book. You are supposed to oil the advance mechanism at 65,000 miles.
The factory Assumed that would happen at about the 3-4 year mark and failed to mention that. As a result the timing siezes up and you’re driving around with the timing off
Because it’s a V12 and most of the time it’s just loafing along drivers don’t notice anything wrong. It’s still starts and runs Smooth and. fine.

Maybe a tiny bit less power and sometimes it needs to crank a bit more before it starts.
Don’t worry it’s not a big deal and easy to check and fix.
ask and I’ll explain the simple steps involved.

i run OAT ready mixed coolant in my V12 , the one designed for aluminium blocks ,
OAT is Organic Acid Technology , and is supplied ready mixed or a concentrate , i use ready mix as putting in ' normal ' water contains a certain amount of other chemicals and minerals that the engine probably wont like , OAT uses distilled or 'purified ' water in the mixing process

i have have used this coolant in my cars for around 10 years now with no adverse issues ,

as mentioned above, the filling process is vital, and once filled correctly , dont be tempted to remove the overflow tank thermostat cap ( or the other cap or bleed screw ) as this will facilitate the need for the engine to run through a hot cycle again to get the correct level , and dont forget the atmospheric recovery tank in the wing, the cooling engine sucks back fluid from this thank to equalise the coolant again for expansion and contraction of the heat cycle , so fill that half way before a heat cycle, you WILL see fluid loss from this tank during the first heat cycle, but not after if you leave the caps in place......

a properly filled and bled coolant system will not give you any issues , even on the hottest of days


BB

Do you know what ratio of water to antifreeze you now have? Once you get much past a 50/50 mix, too much antifreeze certainly will make it run hotter. It just doesn't transfer the heat as well. I would use an antifreeze hydrometer to check it. Shoot for freeze protection of about -20F. Colder than that requires a lot of antifreeze and could result in running hotter.

Gonna chime back in again. IMNSHO the issue with OP's car is NOT AT ALL related to the % of antifreeze/distilled water. It's either an incomplete burp/bleed, or a loss of pressure causing visibly higher
temps than before.

OP did not mention whether or not he used a caustic "radiator" flush at any point during his adventure, if so all bets are off. If a flush WAS used, drain and refill it AGAIN, then replace the thermostat because the flush exposes bare metal in a cooling system; battery actions starts up afresh (dissimilar metals) , metal plates itself from one place to another until the "battery" eventually discharges, and often times the place it plates ONTO is the shaft of the thermostat.

I will say absolutely, unequivocably, do not EVER uses caustic radiator/cooling system flushes, period. On ANY vehicle. Drain and refill is GOOD ENOUGH and CAUSES far fewer problems. Working at a Nissan
dealership I saw ONE AFTER ANOTHER sticking thermostat / overheating vehicles where the owner had decided to use radiator flush to "get it good and clean."

If your radiator or block is so rusted up you're considering using a flush take the radiator to the radiator shop, and pull the motor and have it boiled out. but DO NOT....

Diagnosis of ALL overheating ALWAYS begins with pressure testing the cooling system, and radiator cap. Buy, rent or borrow a cooling system pressure tester. Do not lie to yourself, if that
needle moves VISIBLY downwards, ONE IOTA, during a 20 minute test, you've got a leak, SOMEWHERE. Loose hose clamp, leaking heater core, head gasket, wherever, and a little
UV fluorescent dye can help immensely in finding it. Buy a NEW Jaguar or Stant Radiator cap if the rubber gasket is compressed cracked, or if it fails testing. Or even if it doesn't. Too easy
and cheap a way to rule out a frequent cause of overheating.

Try pressure testing the offending vehicle both COLD, and warm --- warm it up with the radiator /expansion tank cap OFF, shut the motor down, then attach the tester.

A cooling system with a pressure leak, even the TINIEST drip from a single loose hose clamp, will consistently run 10-30F hotter than (chose one: otherwise, before, it's designed to)

Having PROVEN to yourself conclusively the cooling SYSTEM is NOT losing pressure, at all, then consider issues like radiator fans, relays, thermostats, testing for exhaust gasses in the coolant (incipient head gasket failure), leaves/debris in the radiator, etc. You can even remove the t-stat and run without it a few days to convince yourself IT is not the cause of your hot-running condition.

Wrong or incorrect t-stats have plagued Jaguars since the XKE days when a dual-disk t-stat became UNAVAILABLE from British Leyland, and the "common" one-disk thermostat substituted failed to block off the BYPASS line leading to 80% of the hot coolant simply recirculating even when the t-stat was fully open. With the bypass plugged off (with a big enough bolt, nut and washer) that miserable 2-bladed fan originally outfitted to Series 1 XKE's was MORE than adequate. Even in Phoenix.

Installing a 160 thermostat instead of the factory spec (usually 180) again is a incorrect action by someone who has yet to identify and fix the ACTUAL cause of their overheating. So is administration of snake oil additives to the coolant.

When topping up the the radiator AFTER the vehicle has warmed up fill it until ZERO bubbles appear in the neck of the radiator or expansion tank, whatever, and KEEP idling another 15 minutes AFTER that just to be sure.

Yes on distilled water, not tap.

I have given anyone with ears to hear more than enough information here to correctly diagnose and repair 95% of all Jaguar overheating. I've told this same tale at least 25 times on a half dozen different autmotive forums, and STILL folks want to install bigger fans, put in a 160 thermostat, add snake oil, change the gauge sender, and do everything BUT start by PRESSURE TESTING the cooling system on their overheating vehicle.

"You can tell them but you can't make them listen" my SO continually reminds me.

When you properly diagnose and fix your cooling system you can start living again, enjoy actually DRIVING your Jaguar without your eyes pegged to the gauge continually. When you achieve this nirvana you can send me a boquet of roses.

For me it was sitting at a stoplight on the 101 near downtown Santa Barbara, in my XKE, sweating a tad, and instead of being able to focus on the even hotter co-eds in the convertible '67 Mustang next to me, instead constantly glancing between the stoplight and the temperature gauge, WONDERING if the light would change BEFORE the needle went into the red and she began puking coolant was the final straw. I decided I was gonna fix that mother ****ing overheating piece of British **** if it killed me. It was close, but I won the battle. That was oh, some forty years ago.

I used to have a 1964 E Type, and it had been owned by a guy who lived in an area with very hard water. When I got it, when the ambient temperature went over about 21C the temp gauge would just start going up and there was nothing I could do to bring it down. At the time I didn't know about the sliding sleeve type thermostat, and they were unavailable anyway, so I ran a regular thermostat.

However, I decided to do a block flush to make sure the block and rad were clean. I consulted with a chemistry professor at the university who I knew and he advised to use acetic acid. So I obtained some and filled the radiator, ran the car until the thermostat opened and then let the mixture soak for a while then drained it into my catch pan; which was a large rubbermaid tub at least as long as the engine. The mix of water and acid that went in clear came out looking like milk. I let it settle overnight and the layer of minerals in the bottom of the drain pan was at least 1/2 inch thick.

I did a through flush to remove the acid, refilled with new antifreeze and never had any more over heating problems. I figured the acid cleans out my kettle from minerals in the water, why wouldn't it clean out my engine? Turned out to work very well.

Hey! Good Morning!

Thank you all for the stories, advise, pointers and facts! Really!

I always tell on my self. Hopefully it will help me change the way I work for the bettah! Yesterday did some stuff that had to do with steering and suspension. Turns out what I thought might be going on, wasn't and the problem... What I had experienced had to do with my own shoddy work or not coming back and giving work done a second look (bearings)... I need to work better. Get better at this stuff. Stop rushing, for one.

Yesterday I went in to try and re-bleed the system, check hoses and such. I tied into the fire hydrant for flush water,(neighborhood kids liked that) during which I drained the coolant. I looked a little while thinking my car WOULDN'T have a rad drain plug (1990), didn't find one, so I used the low hose.

Q: can the car be properly drained/flushed with the nose up? Or does an XJS need to be flushed running, level on the ground?

I drained and caught as much as I could. Messy. But no big deal.

I then removed both thermostats. Plan was to flush for a while with thermostats OUT. And this is what I found. It looks like the RH thermostat was NEVER properly seated in the small groove that runs around the block side of the thermostat casing. That when I went to place the cover (2yrs ago), it had fallen out of its groove and got pinned between the two faces of the thermostat casing BEFORE I could place the outer face. 2+ yrs!!! NEVER leaked, overheated or ran hot until I did a top end refresh 2 weeks ago - intake and cam cover gaskets. Used RTV and a gasket on the thermostat, which probably explains the no leak. I felt and looked onto the casting for the thermo and there is no way being THIS out of line, the thermostat could have ever have sealed or blocked completely the inner coolant flow/direction port as designed. Bugger.


I used some red markings. If you look closely you can see witness marks that show how FAR thermostat was from being centered in its seat. Gasket had indents where misaligned thermostat sat for 2yrs. CRAZY SHODDY.


So, I reused old gaskets with a smear of RTV (no leaks) and carried on.

Telling on myself again - nose up, I started up the car and filled it slowly as described. Thermostats in of course. Slowly slowly and things started heating up. Got steam coming out of the bleed, followed by geyser of air and coolant, and then pure coolant, and a bit bubbling out of the reservoir. Capped reservoir and continued filling (couldn't over worry about coolant on the street - feel wrong about it but HEY!) at which I went with the bleed screw taped on a 12mm socket and got it covered. Then capped the main tube... Done????

MISTAKE - can you BELIEVE that I never went and tightened DOWN the bleed screw!?!?!? Drove 12+ miles. 80+degrees and the car ran much cooler (like it used to) for a while, then started getting hot again. Got to my destination to realize that I had FORGOTTEN to tighten down the bleed. Thankfully it was still there, loose, but there! For my neglect I had lost more than 3/4 of a gallon of coolant between Staten Island and Brooklyn - AND MOST LIKELY HAVE TO REPEAT THE WHILE PROCESS,,,, feeling like a dope. Not toooo terrible tho. My girlfriend is laughing at me 😂

That's my story and I am sticking to it.

TEMP-WISE she was running more like "NORMAL" for a little tho. That's encouraging...

I need to be more careful and better at this.