Ok, looks like I screwed up my V12 engine.

Last weekend it overheated and as I pulled over, it started steaming. The steam did not come out by the coolant filler caps, but right in front of the windshield. And the tail lights and trunk had droplets all over.

Today it barely started and will not stay running. One drive around the block proved that it is not roadworthy. I also get a rubbery smell when driving.

My prime suspect is a head gasket. Any other ideas? You don't have to tell me that I royally screwed it up, I already know that.

Looks like the perfect opportunity to start learning how to repair this engine. :-) (I learned how to rebuild old Beetle engines after burning up the lopes on a camshaft trying to go 90mph.)

What a day!

 

I admire your positive attitude.

 

Sorry to hear this. When they run, they are beautiful, and when they break down it can be quite disheartening.

Still, it's just a car and will take parts, time, and $ to set right.

While you're in there doing whatever, take care of as much else as possible!

 

OOPS.

Sounds like one of the "easy" heater hoses let go.

Lots of unknowns obviously, but if it got SERIOUSLY hot, then the cylinder heads may have "gone soft", which is basically a polite word for throw away.

The fact it runs at all is a partly good sign, and may not be terminal, and finding the external reasons for the running issues may be all it needs.

Good luck.

 

Did you see the temp gauge going up at or immediately before you suspected the engine overheated?

 

When I pulled over, the temperature gauge went up from N to the middle between N and H in a very short time, whithin two miles from the gas station where I had stopped. I had shifted manually and run from 0 to 60 mph in first gear.

Today, after barely making it around the block, she seemed to run just fine two hours later when I drove her back into the garage.

 

Weeeeeell.

That Lotto got won, and it was not you, but you might JUST have dodged a bullet worth about the same.

If there are NO strange "tapping" noises, etc, then the valve seats sound like they are behaving and staying in place.

Now the reason for the steam etc is to be found, AND, if it were mine, ALL the coolant hoses would be changed with NEW clamps, both thermostats changed, heater tap checked very carefully for pressure leaks (they are cheap so a new would be smart), and then fill and bleed, and see what happens.

 

Ignore this advice at your peril!!!

 

My plan was to replace all cooling components including the water pump and all sensors. My last XJS stayed cool, no matter how hard I drove it.

 

VERY VERY smart XJS owner.

Wish there were more like you.

Keep us posted, my fingers are no longer crossed, I needed the blood flow to return, HA>

 

We've heard it a hundred times, Jaguar V12 credo:

"Do it all, do it once, do it right. Then forget about it for years"



Cheers
DD

 

Good advice. Hose clamps can't be counted on as a forever thing. With age they'll sometimes refuse to hold tension.

A "FWIW" tidbit.....

I've found that the Jubilee brand clamps are very high grade and long lasting. NOT inexpensive.....about 4x the price of an ordinary clamp at your local auto parts store. But if the budget allows, worthwhile

https://i.ebayimg.com/images/g/ZuYAA...Pgc/s-l300.jpg

Cheers
DD

 

It seems that luck may have struck. What looked like a major disaster is only a "minor" one.


Hose and clamp failure and perhaps the heater valve. Lottsa coolant escaped. Enough to go under the car and be sucked up on to the tail lamps by the low pressure there.


Along with the WP and hose and clamp replacement, I'd remove the radiator and have it serviced. That would alos allow an opportunity to clean the debris behind the AC evaporator or is it condenser?


Alloy engines don't do well in heat.


Composite ones even less. Don't ask....


Carl

 

My car overheated once and blew a hose on the highway. Valvetrain was loud as hell as she overheated but that was 7 years ago and I still drive it daily.

I took a look in the engine bay where the coolant was and immediately assumed it was the head gasket. It was actually one of the heater hoses. (Coolant sprayed onto edge of head).

You probably just had coolant on the brakes from the wind pulling coolant over the roof down to the rear of the car or underneath and up.


The only big worry on these cars is overheating causing dropped valve seats, but I can't say I am a member of that club and I overheated the **** out of mine. The V12 is quite a robust beast.

 

Aluminum radiators are now available for less than $300 if yours is in question

 

Me too, when I forgot to put the thermo fan fuses back in and went for a drive on a 42°C day, lost most of the coolant at a set of traffic lights. That was 5 years ago and she is still going.

The later V12's seem to be far more robust in this department. I have never heard of a 6.0L dropping a valve seat.

The heater hoses are a PITA to replace as is the heater tap. When I did mine I used a GM heater tap from an Aussie Commodore, been in there now nearly 10 years.

 

An addition to your list from downunder.

The steel,well metal anyway, pipe that runs across the front of the engine, with the filler spout as part of it, is prone to rotting out on the underside, usually just above the water pump.

Last one I got was stainless, and about $125, but when I inspected the old one, and not too closely, the pin holes were held together by rust and a small amount of paint, so a disaster like yours was only a few kms up the road.

 

Tomorrow the princess finally has her shop appointment to get the cooling system replaced. I am hoping for less than $2000.

 

So cool: My XJS 'Princess' goes 70 mph in 90 degree weather without cooling problems. My mechanic replaced the entire cooling system except for the radiator, even 26 hose clamps.

And on her 200 mile test run she even earned her H.E. badge at 17.2 mpg.

It is a good day in lala land.