Wife was sitting at idle in long line at emissions testing with AC blaring and car overheated. Let it cool and finally started. On driving home, temp seemed to be running hot, but did not get to the "red zone" due to finally getting some air flow. I'm thinking my water pump finally took a poop...any suggestions? should I r&r the thermostat while I'm at it?

Thanks, J

 

When was the last time any maintenance was done to the cooling system?

If none of the components have been replaced for a long time, it's the perfect time of year to go through and replace them all. All can be done for roughly $200 and you don't have to worry about having problems again for at least a couple years.

I'm talking radiator, water pump, thermostat, fan clutch, hoses, rad cap and fresh coolant. If you do it all at the same time, you only have to drain and refill the system once.

And it would also be a good idea to take off the thermostat housing and water pump, stick a hose in the thermostat hole and flush out all the gunk that's sitting in the block.

After all this and a fun-filled afternoon, your XJ will be running cooler than ever

 

Drove it twice more today and seems fine. Holding at 210. Something about idling with the A/C on put it in the red zone. Any further thoughts?

 

Maybe possibly a heat soak issue. Is it throwing any codes.

Ps.I'm dealing with a similar issue on my 96

 

Not sure what heat soak is. I don't think there's any codes. I'm not sure my water pump is working properly. Is a water pump a binary piece of equipment (either on or off) or can it fail over time and not push enough coolant on hot days with the AC running?

 

It sure could fail over time. The water pump is working whether the AC is on or off. Same goes for the rad, thermostat and fan clutch. Which is why I suggested giving it an overhaul

Do you know if your electric fan kicks on once the temperature reaches 212?

 

Did some further research on heat soak. I'm not sold on that.

Other research points to the radiator going bad. Having the original rad makes for probable corrosion on the interior. The corrosion blocks the cold/heat transfer.

Best answer may be to replace it all, but still looking for answers. I think my WP is weeping anyway. Still undecided.

 

same exact thing happen to me the other day it overheated at idle and started up but i towed it home cause it was a long drive home

 

I'll ask again, have you ever done any maintenance? If not, it is a good time to replace every component of the cooling system.

 

Checking fan operation tomorrow.

I agree to swap it all out...Just watching the nickels and dimes having not made squat since Lehman brothers went broke.

I need to make some dough before I do non-essentials. My masters degree is in real estate and construction management, so you can imagine how much I'm making these days ($0.00).

Luckily I've been fishing a lot to ease the pain. One week on the Big Horn in Montana last week.

 

Do u ever feel like when talking maintenance, especially the cooling system. I rotf,lmao when I read "I'm overheating but don't want to just throw money at it". I would bet a lot of job interviews would go further to easing the pain than fishing.

 

Easier said than done. I take it you are gainfully employed. I've sent out hundreds of resumes brother. What do you do for a living? ...and by the way, I said I didn't want to do the non-essentials, which is why someone might come on the forum in the first place...what a richard.

 

After 45 years of working hard in oil & gas I likewise am unemployed.....some call it retired. Scrap up +/-$250 and replace the entire system, including the radiator, on a Saturday afternoon.

 

This particular water pump (the one in the 4.0) tends to degrade gradually. The fins on the impeller wear down, slowly reducing the amount of water it pumps.
I've seen pictures of them with basically nothing left but the shaft, lol.
While yours isn't that bad (you'd be overheating all the time), it may be worn enough to have slowed the flow somewhat.
Couple that with a marginal radiator and other old cooling system parts and the reserve isn't there anymore for the A/C load.
That's why folks say to change everything. Because it often isn't just one or two worn out parts....it's the sum of all of them.

BTW, is your AUX fan coming on with the A/C? The additional electric fan?

 

Having friends who formerly worked as mortgage brokers, contractors and RE agents...you aren't kidding that certain occupations are really, really tough right now. Most of those related to real estate are really squeezed. There just aren't any openings.
Might be time for the 'ole career-switcharoo. I had to do an about-face at 35. DW at 49. Roll with the tide and keep your head above the waves..