Cooling system

OK - $10.00 on the thermostat - my check is in the mail to Patrick. Keep us posted Ray.

Stew Cleave
JOCO Chief Judge
'69 E-Type 2+2
and other LBC's

Ray: Never heard if your other fan is missing and if there's just a big hole in the shroud where it used to go?

Patrick McLoad
1966 E-Type, Right-hand Drive Roadster
#1E1445

PS: I'll hold the money.

Ray:
My money is on the thermostat despite the fans being AFU. Who's gets to hold the money? Can you post the pictures on this thread - its really easy just follow the directions - I tried to do it from memory once without reading the directions and got AFU.

Pascal:
Its ok to say "all fouled up" on this site, isn't it? :)

Stew Cleave
JOCO Chief Judge
'69 E-Type 2+2
and other LBC's

Ray Suchta
Mike,
I'll email photos tomorrow. No I don't think it ever worked correctly. I've owned the car for a year and it always ran with the temp guage needle on "L" in normal. Would creep up to the red range on very hot days but never pegged the needle like it does now!. I have a 72 TR-6 that rarely reaches the center of the temp guage, even on 90 degree days, so I'm spoiled I guess.

Ray:

Did this ever work for you? It's just not right. The two stock fans would have been 10", and pulled 600CFM each if in good shape. An aftermarket 12" fan might pull 1000CFM. Not enough to keep the motor cool, especially with a/c. Can you post a photo? It would save a dozen questions.

Some sort of bypass is needed for proper operation of the thermostat. If the hose is missing, then the bypass is gone. They may have installed a thermostat with a "bobble" bypass,or they may have just slapped in a standard thermostat. In the latter case, a quick and dirty solution is to drill a 1/8" hole in the flat part of the thermostat. Otherwise, you will need to find the special S2 thermostat, with the bypass that Stew Cleave described, and replace the hose. The purpose of the bypass is to allow a little bit of coolant to circulate when the engine is cold, so that heated water will eventually reach the thermostat. Omitting it will extend warm-ups. Again, a picture would save a thousand words.

The dumbest thing that Jaguar did on these cars was design the cooling system to be low pressure. Leave the 13lb cap if it's in good shape. Going to 7lbs will make your problem worse.

Mike Frank

Ray Suchta
Mike,
Thanks for the reply. Only one fan about 10 or 12 inches mounted on the right side of the radiator. Runs constantly. The capped tube is on the right. Could be the by pass hose you mentioned. i will check that fan is running in the correct direction and check the thermostat to make sure it is opend at the right temp. My header tank is correct. Now that I don't have the A/C in the car can I goe to the 7psi cap in lieu of the 13 psi cap?

Ray:

I think you've had some good advice here, so I will try not to be repetitive. Your fan set up isn't stock, and given that you've removed the a/c, I'm still betting that the problem is there somewhere...either the fan isn't working, isn't coming on at the right temp, or turning backwards. Does the fan cover the whole radiator, or is there just one 10" fan?

The overflow tube on the header tank is supposed to go nowhere, as odd as that sounds. A few years back,I was running at Limerock, and the tech inspectors made me put an overflow bottle on...I improvised with an old oil bottle. Poked a pencil hole just below the neck, stuffed the overflow tube in, and hid it behind the battery. I've kept it there ever since. Works, too: once in a while, I have to empty it.

Is the capped tube on your radiator really on the left side of the car? If so, then your radiator is also an aftermarket item. You should have three fittings on the top tank: the overflow tube (which goes to the header tank), the big input hose from the thermostat housing (right side), and the small bypass hose from the thermostat housing (which is right next to the input hose). There should be no fittings on the left. You should also have an Otter switch on the front of the top tank.

I have a cooling system checklist that I send to my customers...I've sent you a copy by e-mail.

Mike Frank

Ray Suchta
Stew,
I will check the thermostat. My expansion tank, hoses etc. is installed correctly. I will check the fan, make sure it is "pulling" and not "pushing". The fact that I only have one fan gives me pause.

:-)

I know..... new stands for Never Ever Worked

Pascal Gademer
South Florida Jaguar Club
72 E-type 2+2
00 XKR Coupe
99 XJR

Ray: Check the thermostat and make sure it is of the proper (original) bypass type with the small nylon ball and tee shaped thingy in the bypass hole. All Series 1.5 and 2's had two fans that pulled air toward the engine. The expansion tank is small and mounted on the firewall, a 1/2" o.d. hose runs from just below the radiator cap along the rails to the middle of the expansion tank. An overflow tube runs from just below the expansion tank cap to atmosphere, below the stone guards (bottom of engine compartment). The cap on the expansion tank is 13 psi w/ac and 7 psi without. The system should be topped up (final and periodic filling) through the expansion tank. Always test the thermostat by placing in hot water on the stove and observing when it opens with a thermometer before installing (you can get a bad one out of the box). For example, a 180 degree thermostat should begin to open at 180 degrees.

Pascal: The fact that we can get bad new parts fresh out of the box is one reason why many mechanics don't like to replace things unless they are broken - I'm referring to the coil problem on another thread. This bad out of the box problem's been around along time - not something new.

Stew Cleave
JOCO Chief Judge
'69 E-Type 2+2
and other LBC's

Ray,

the first thing is to check the actual temperature. use an IR thermometer point it where you find is the hotest point in teh cooling system. In the V12, the Tstat housing is the hotest point, not sure where it is on the 6.

That will cfm that you have a problem.

#2, check that you don't have too much coolant in the system. If so, it will spill because of expansion when hot until it stabilizes to a point where it won't spill.

#3, check that the fan starts after engine is warm while sitting and blows in the right direction... don't laugh.. it's happened to a few guys...

#4, Tstat, water pump, hoses... on the V12 a common cause of overheating is the lower hose collapsing uner suction when they get old.

If you are indeed overheating to the point that the gauge pegs, if it is accurate, you have a major problem. that woudl eliminate the rad as a suspect. I'd think aradiator problem would show more as a gradual overheating, not drastic.

Pascal Gademer
72 E-type 2+2

Ray Suchta
The condensor, compressor, drier, etc. and all hoses are now out of the car. Took it out for a test drive and within 10 minutes temp. guaue was pegged in the red zone. Coolant was flowing out of the expansion tank onto my drive way. My car only has one fan so I was wondering if the A/C installation was after manufacture. Also the hose from the radiator filler neck runs to the expansion tank. Second hose from expansion tank runs nowhere! Should there be an overflow bottle or some thing? Also, at the top of the radiator to the left of the filler neck is a hose which has been capped off. Where should this have gone? What are trouble shooting procedures now? Thermostat, radiator, water pump? Cooling system was drained and flushed last September. Only about 500 miles since then.

Patrick:

The "normal" output voltage of the IVR is 10 volts, but it's not DC: there's a bimetallic strip inside the IVR which makes the circuit until it gets hot, then breaks the circuit. This can happen hundreds of times a minute, yeilding a sort of square wave pattern. The importance of this is that you can't check your IVR with a digital voltmeter, it won't register correctly.

It's very easy to replace the instrument voltage regulator with an LM317 solid state adjustable regulator. All the parts you need are available at Radio Shack, and the schematic is printed on the back of the LM317 package! An LM317 produces a much cleaner and more accurate output voltage than the stock unit, and you can calibrate your gauges by simply adjusting a potentiometer. If you are a good hand with the soldering iron, the new circuit can be built right into an IVR case, so it will even look correct.

On a separate issue, the Ser II Otter switch is located in the radiator, not the header tank. If it's not fully submerged, then your radiator is seriously depleted! The Series III Otter switch is located in a fitting in the lower radiator hose, so if that's not immersed, you're empty!

Mike Frank

I agree with George that there is a very loose association of actual temperature to the gauge indication. A while back, I checked with the Nisonger folks and they there is no way to calibrate a gauge to temp. sending unit as needel deflection is dependent on the 12 volt instrument rectfier mounted on the panel. Two different rectifiers can give two different readings, and they are not manufactured with any precision whatsoever. So, if you are not blowing water out of the cap, then you are probably okay.

I'm not sure where the otter switch is located on a series 2, but I assume it is on the header tank. As you know, if the switch goes bad, or, if water level eventually lowers to where it is not touching the switch, then your fans may not come on...this is why most folks hot wire their fans directly. I always check to see if mine has switched on.

Could it be possible that your fans are not up to speed? You might consider a set of CoolCats to greatly increase the amount of air drawn through the radiator. I put one on my Series 1 and it works great. The best part is that they fit in the original mounting bracket and use existing wiring. When showtime arrives (if you are concerend about concours scores) these can be removed and your originals put back on.
Here is the CoolCat link:
http://coolcatcorp.com/Merchant2/merchant.mv?Screen=CTGY&Category_Code=CS

That's my 2 cents; good luck and let us know.

Patrick McLoad
1966 E-Type, Right-hand Drive Roadster
#1E1445

George:
Thanks. I stand corrected on the rich/lean thing - now that I think about it, it makes perfect sense that lean would run hot. I got the foam piece over the radiator, now I need to put the bottom sheet metal piece on.

Stew Cleave
JOCO Chief Judge
'69 E-Type 2+2
and other LBC's

Stew- running rich will not overheat you-lean will. I have over 300k+ on a SII with ac- you need the foam and the closing pannel. Running the fans all the time is a waste. In some situations it hurts cooling. As far as the gage it was changed to stop worriers. If you are not in the red you are not overheating. If in doubt look and see if you boil over when you stop. There is no relationship of the NORMAL to a specific temp. What I do for my customers is make a chart and read the temp at the manifold with a laser and record at each letter. L is ofter about 180 but it varies. As far as the unhooked ac goes me thinks I would look at the wiring that was rolled up and stuffed in the facia.
George Camp

Ray:
What did you do with the wires? They aren't touching so that the compressor comes on are they? Before I installed my AC system, after restoring it and getting a good valance, I ran with the guage straight down at normal. After instaling the condenser (component in front of the radiator) I ran at the L in normal. This in a 2+2 with automatic. The guage seems very sensitive to ambient, running much cooler in 40 degree winters and much hotter in 90 degree summers (at the end of the L). I've been told the foam shroud over the radiator and the sheet metal deflector plate between the bottom of the radiator and the frame is very important for proper cooling. Most cars are missing these pieces, including mine, but not for long. BTW, I looked 10 years for a good presentable interior A/C valance with all the louvers intact - this component is hard to come by. Also, if you are running rich you will run hot - check the color of your spark plugs - should be chocolate brown, not black. If black you're running rich, could be your float setting.

Tell us how you make out - we like feedback.
Stew Cleave
JOCO Chief Judge
'69 E-Type 2+2
and other LBC's

My '68 never had A/C and the relays have been bypassed so the fans are on when the key is on. Mine also also runs in the upper end of normal and on hot days in Texas would creep up close to the red. After doing all the obvious things like flushing out the system and rodding out the radiator without satisfactory result I changed out the indicator voltage stabilizer on the back of the indicator/switch panel and so far it has not indicated past the L in NORMAL. Not sure yet if I have a final fix as I just changed it over the winter but it seems to be doing better. You might want to stick an baking thermometer in top of the radiator to help see if it really is hot or an indication problem.

Ditto with Mike's response. Check to make sure the radiator cooling fans are coming on.

Also, if you have removed the underdash unit you might as well remove the condensor in front of the radiator, the compressor, the hoses and the dryer. If the Series 1-1/2 set up is the same as a Series II this should be pretty easy to do.

Doing so will remove about 40-50 pounds from the front of the car and increase airflow through the radiator. I would save the parts however, you might someday get the urge to have AC in the car or a potential future owner may want it.

Regards, John

Are your fans coming on? The SII a/c system has two fan relays, one is controlled by the A/C system. At first glance, I don't think there's any way that removing the unit would cause the set up not to work, but that's the only place the A/C and the cooling system come together.

Mike Frank