So I am headed home from work, everything seems fine, and then I see the temp is headed to the top of the gauge. I'd just gunned it to merge onto the interstate. I got off the road and park, there is coolant all over the left side of the car and the engine bay.
My best guess was that my thermostat wasn't opening, so I got a new one and replaced it in the parking lot. Started it up and let it come to temp but the needle just kept on going. I heard some odd pops from the engine bay after I first started it up, but metallic clangy sounds, but then it seemed to run fairly smooth. The temperature did seem to rise pretty quick, but it may have just been paranoia or because the block was still a little warm.
Now I am waiting for a tow truck.
There was no coolant in the oil, but I am fearing the worst. Any ideas? Things to check?

 

These cars will make some crazy noises in the coolant path when running hot! Where did you get the thermostat? The car is particular to the correct thermostat usually from a jaguar supplier. No coolant in the oil/oil in the coolant, all is prob fine. But don't run it until you get the cooling issue solved. Where did the coolant leak come from? check all hoses?

 

Hi there. Now that the engine has cooled down and you have a calming coffee at hand . . . we can review. First, backtrack to original boil-over and try to picture source of escaping coolant . . . if a burst pipe, that's your priority coz it will recur until you replace it . . . if from header filler cap, then most common (but not sole) cause is sudden failure of thermostat, which you have now replaced.

Word of caution . . . some modern ultra thin pellet style replacements can be reverse fitted, which immediately replicates a "stuck shut" condition. A simple strategy for any sudden overheat condition is to remove thermostat once engine has cooled sufficiently not to scald . . . bolt housing minus suspect thermostat . . . refill slowly, carefully, if possible with engine idling. Stop engine, top up header and re-cap. Start engine; a few jabs on throttle; engine should not venture past "normal". If resolved, thermostat was the cause and you can safely drive car to supplier for a replacement thermostat. If not resolved, broaden your search.

Most embarrassing "boil-over" for me was wedding night 50 years ago . . . mates had adorned our getaway car with cream, confetti, streamers, tin cans off rear bumper . . . huge fun . . . but with car parked nose to wall, I failed to note the wide cardboard sign "JUST MARRIED" fixed to grille and totally obscuring radiator. We made it about 10 miles before boiling and clanging to a sudden stop!

The good news is as suggested by [slofut] . . . engines can be somewhat forgiving, but keep a watch on oil pressure as well as coolant temp.

Best wishes,

Ken

 

or a water pump impeller self-destroying?

or the lower radiator hose cracked?

 

Hi all, very reassuring. I got the thing home and tested the old thermostat that I pulled out of it and found it to be functional.
I double checked the new one from NAPA, it appeared to be identical. I installed it the same way the old one was in.
I couldn't hear the coolant escaping when it boiled over until I got off the highway. Most of the coolant seemed to be coming from the catch can sort of thing found under the front drivers side fender, a lot also seemed to be coming from header filler cap.
After I replaced the thermostat and filled it back up with coolant, I idled all the way up to temp and a bit beyond, and it didn't leak.
I remember that the lower radiator hose was cold when I pulled over, so my suspicion is still that coolant isn't flowing. My best guess right now is that the radiator is plugged. I'm finding it hard to find radiators for this thing online. Jagbits has one for an 81 but it's $400, anybody know of a good supplier for a radiator, are they that hard to get a hold of now? Any non OEM options anybody has tried?
I replaced the water pump about a month ago, and flushed the coolant then. If the impellor failed, I'll have some harsh words with the supplier.
I won't be able to take a deeper look at it until Monday night, I am in the process of moving and my weekend is spoken for. Thank you all for your replies, I found it very reassuring.

 

Ok, also, it's a lot easier to find a radiator for an '82 and up. Why is the radiator different for 79-81? Anyone know if I can swap the too fairly easily should the need arise?

 

you could have the radiator serviced or re-cored, keeping the original upper and lower caps. or you can contact David at www.everydayxj.com to see if he has a good used one.

the "bladder" under the fender is an expansion tank for the expansion tank in the engine bay, sounds like the coolant is boiling and expanding past the expansion tank.

this could be a bad water pump impeller as well.

when refilling the coolant, make sure the engine is idling at normal temperature, Heater is ON, and the TEMP is at maximum heat, so coolant flows through the heater core and the system is fully filled.

 

I've had my misadventures with various critters over heating. The burble and gurgle appeared in most!!!


All iron engines handle it better than those with an iron block and alloy head/s.


A leaking radiator cap is not a good sign. Overflow via the tank behind the left out board tank is at times, others not so much.


Some have searched and found Mustang and Camaro alloy radiators that adapt to the SJ chassis with minor changes. Relatively cheap.


But, if it fits your needs best, as Jose suggests, fin a reliable shop to fit a quality
core. All cores are not equal!!!


When my 4.2 blew it's top, the fascia guage was too late.


Carl

 

As far as I know the only difference is that earlier radiators have a hole for the low coolant sensor. On later cars the sensor was moved to the tank on the LH inner fender.

I agree with Jose that you should try having the radiator professionally cleaned/repair at a local radiator shop. Worth a try; you might just need good 'boil out' and face only a $100 bill.

Also, it's common for these radiators to clog *externally* with leaves and other debris

Cheers
DD

 

Was a water pump impeller.


Ok all, I finally got to dig into this and water seemed to flow freely through the radiator so I pulled my water pump. Pieces of the impeller fell everywhere. See the picture. Very catastrophic. I replaced the water pump a couple months ago with one from A1 Cardone through RockAuto. To their credit, it has a two year warranty and they would have replaced it for free, but I didn't want another from the same group so I sourced a different higher grade pump (AC Delco), also from RockAuto. Hopefully the new one doesn't fly apart when merging into traffic. I don't get it until April 10th, so the poor girl will have to wait until then. You'd think you would be able to hear that go, but honestly I heard nothing. Then again, you can't really hear the motor running in these things.

 

Looks like Jose nailed it in post #7 !

A broken impellor is something you hear about but don't actually see all that often. A good example of "never say never" !

Cheers
DD

 

Yep, way to go Jose. The impellor seemed fine when I installed it, but looking closely I am surprised by how thin and poor (pitted and bubbly looking) the casting is. Now working on MGs I've seen my fair share of poorly crafted metal parts, but given the first water pump lasted more than 35 years, I think I will very carefully compare this impeller with the new one when it comes in and post my findings. I wonder if some process A1 Cardone is using when the remanufacture may weaken or damage the metal. That or there was something large in my coolant line which washed in there and got caught between the impeller and the housing and caused the thing to come apart, but that seems kind of unlikely to me.

 

Jose sure got it right on the nose!!


I've seen seriously corroded impellers in other critters. but, never one that flat out disintegrated !!!


On the bright side, two points:


1. The engine suffered no damage.
2. The cause is clear and unamibigious (sp)?


I wonder if A1 Cardone uses used impellers or new castings?


Yup, I sure can see a lack of confidence in another from the same source.


Angst? Would the AC Delco be any better???


Water does not compress. It's hydraulic force is tremendous.
back in my insurance claims career, my employer insured a company that leased and operated a former Navy ship yard. It's main claim to fame was a huge dry dock. A huge electric driven water pump was used to empty it into SF Bay. The works was accessible via a ladder. A huge brass impeller. Issue was that debris got into the pump camber and bent the huge fins way back. Lots of $'s to "make" a new one and refit it!!! Some investigation found prior failures during Navy service and after. And changing material from which the impeller was forged. The Ship Yard relied on an experienced Marine Surveyor's opinion that debris damaged it. Covered by insurance.


My instinct said not so fast. The blades are bent back not irregularly or with pieces missing. So, I retained a forensic lab with hydraulic and mechanical engnering talent
"aboard". Force lines on the unit in situ were established from many plots to measure. A drawing was created to demonstrate them. Very analytical. In lay terms, the blades bent when turned with great force against a near solid obstacle. Many cyles til failure occurred. Elasticity over brittleness resulted in a bend rather than fracture.


In the Jag pump, the brittleness gave way....


Carl

 

A1 Cardone Impeller


AC Delco Impeller


Ok all, I got my new water pump early. This difference is substantial and just goes to show that you can go cheap, but not too cheap. The A1 cardone impeller is considerably thinner and the casting is very poor. The AC Delco impeller comes all the way back flush with the shaft, and I don't believe that is just differences in installation, and although is machined in the back, doesn't have the same sandy/bubbly feel on the raw cast surfaces that the A1 Cardone pump does.
I installed the AC Delco water pump, but then ran out of daylight so wasn't able to finish. Hopefully I'll have it all put back together this weekend and the Jag will go back to my dailly driver monday next week. She has her work cut out for her, the main road into work is closed for bridge repairs and my drive to work is now 50 minutes each way.
I recently moved my family to a new city for work, I have a new house much closer to work but I don't get to move in until the 28th. In the meantime I am going to be putting a lot of miles on the Jaguar. The water pump gave out after just a week of that, I have a feeling it won't be the last thing to leave me stranded.

 

ok ok, did I win anything?

I am starting to wonder if the original water pump was / is from General Motors?? These cars were built with many GM parts, examples being the Power Steering Saginaw Pump, the AC Delco Air Pump, the Harrison A/C compressor, the AC Delco Ignition Amplifier, the BW transmission, and the door electric mirrors were from American Motors.

Anyway, the GM water pump looks solid.

 

Jose:


Naah, this ain't Vegas.


Parts origins are interesting. Even the big guys buy elsewhere. None can do it all in house, certainly not a small maker like Jaguar.


1. Borg Warner is an independent company and maker of transmissions. Their products have been provided to may car manufacturers over the decades. The BW over drive was once very popular. Three on the tree plus OD was actualy six forward gears to play with. My 49 Mercury was so equipped. With it's 4 to 1 final drive, second OD was very lively. And, it could cruise happily in 3 Of.


2. I'm not sure as to the real relationship of AC Delco to GM. Rebuilding stuff seems to be a present mainstay. Gone independent?


3. Interesting as to the electric door mirrors. I have my doubts as to AMC actually making them. As a relatively small manufacturer, I expect they bought a lot from outside. Thusly, the mirrors from a common out source.


And, I sure do agree that the ACDelco water pump rebuild looks far more solid than the failed unit!!! An awful casting !!!


Commutes: Oh yes, I remember those days well. In the late 60's and early 70's. We lived in CA's famed San Fernando Valley. My job on mid Wilshire, about 25 miles one way. I was fortunate !! Some of my fellow workers came from a lot further away!!!
I soon just plumb wore out. We moved to the SF Bay area. Rode the BART. Not perfect, by a long way, but much better to "leave the driving t them".


Carl