Antifreeze leak

My 1989 XJS 12 2 door drove a 15 mile trip. When I got out of the car there was a substantial amount of antifreeze pooling under driver front fender, . The drive had been great, temp good, no smoking…
Its been in garage and I’ve started it briefly, red radiator symbol appeared on dash. The next start a day later, nothing on floor under car, no dash warning. Can I drive the car?
I let it run til warm (because nothing on floor) til temperature almost to the “N”
Again, no leak, no smoke , Sat there purring. Kathy.

There is an expansion tank right there, it just overflowed. No big deal.

Sounds like one or both of two things. The pressure cap on the atmospheric tank is weak allowing coolant to overflow the overflow bottle in the fender well behind the from left tire or there was actual overheating which overflowed the atmospheric tank and over flowed the blow out coolant in the over flow bottle in the fender well. At any rate the level in the atmospheric tank is also low of coolant and must simply be filled. This is first action to take and to then see if the problem persists of coolant flowing out of the overflow bottle in the fender behind the left front tire.

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Thanks so much for the help. I added coolant to the little reservoir on left fender, ran it til warm (idled perfect) and no new leak.
Is it ok to drive?
Older lady here and Don’t want to be stranded on the road . Kathy.

As long as the cooling system is full, it’s not overheating, and there are no large active drips as it runs, you’ll be OK… for a small distance.

It needs to be gas-checked–to determine if a head gasket is bad–and pressure tested, to locate any external leaks.

Yes, then it is OK to use normally. The red idiot light on the dash will tell you if there is a need to fill it. It always comes on when you turn the key to the on position but don’t turn it over to start it. Read up on what each highlighted red symbol stands for.

Happy cruising.


Added to the little reservoir on left fender?

I thought the place to add coolant (slowly) is the cap on the crossover tube, in the center. With the bleeder on radiator top left screwed out so you you can tell when full – see fluid coming out.

Then button up all caps and bleeder, run car at 2000 rpm with defrost setting and max temp for couple minutes. Shut down and recheck level in the crossover tube filler. Should be 2 to 3 inches below cap.

And Kirby would further recommend adding one of those plastic Ts used for backflushing the radiator. Add it just ahead of the heater valve…highest point in the system…and it is a great and easy place to burp your system and add, as necessary, fluid.


Jim’s points are all valid and the correct way to add coolant is indeed from the crossover tube in the center as every time you open the expansion tank you introduce air into the system.

Nevertheless, your car emptied all it’s coolant for a reason.
Either a defective cap, either excessive pressure due to a head gasket failure.

As a starter I would change the expansion tank cap and keep a close eye at the coolant level.
Keep in mind that it’s normal for the level to be a couple of cm lower than the top when you check, but not more.

All the best.

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Actually, an other reason could be a thermostat that was stuck closed, and possibly the one on the A bank (Right side) as the gauge did not show anything (the temperature sensor is in the B bank).

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Well, that wouldn’t do it unless there were other problems as well.

Wouldn’t that bank overheat?

Of course not. It still gets plenty of flow via the bypass back to pump inlet. The only downside is that there will be less flow through the radiator, which might cause both banks to run warmer – but it might not, the reduced flow through the radiator only reduces the total cooling capacity a few percent. If the engine actually starts overheating, the cooling system probably needed attention for issues other than the sticking thermostat.


Update…I found "pepper " all over engine. Seller won’t return my call. Stopped driving my beautiful car after only two times.


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Maybe trying to clog a leak, have always heard it can be used for that in a bind. Probably an old wives tale