Anyone seen the Gates brand pump in the flesh to be able to say metal or plastic impellers?

 

Just an FYI, (and not intending to detract from our sponsors) most our Public Library's provide AllData free of charge.

Vince

 

does your local library have late night hours or web access to alldata. I dont know about you but I like to access stuff as I go anytime day or night

 

That hurt LOL

 

Simply passing on useable info Brutal. What forum member choose to do with it is their business.

Vince

 

The fans seem to be operating. I hear the fan running at overheat conditions at high speed after the car is turned off. I always assumed that if it runs at high speed it must work at low speed too.

I haven't checked the rad for being plugged. I know that may be an issue if my thermostat housing problem caused a piece to lodge in the rad.

 

So, with the help I've received from this forum, I was able to replace my water pump on Saturday.

Ended up draining the coolant, removing the air intake (which required loosening the brake fluid reservoir), removing one coolant hose (directly above/in front of the water pump), removed the belt, pulley, and then the pump and (metal) gasket.

I had avoided removing the thermostat housing and throttle body, so it was all a tight squeeze. After removing the old pump, I was surprised to see that it all looked ok (including impeller). I then looked down as best I could and felt in/around the ports. I found a small bit of plastic (about the size of a nickel -- see pic). I presume is an old part of the previously cracked (and dealer replaced) thermostat housing. It was sitting just in front of the pump, so I think it fell out of one of the ports. I couldn't find anything else in the area. This was my "AHA" moment. I did not try to look into the ports with a mirror.

I installed a new pump with (paper) gasket and put everything back together. I filtered the coolant and found a few small bits of debris (nothing larger than a grain of sand).

Once everything was back together I didn't have time to do a proper test and put the car in the garage.

Next day, wife took the car out. No warnings came up but it was still hot (as determined by an OBD tool when she returned). It was at 106 C. I know that the jaguar "overheating" light comes on at 119C -- there's no reason an idling car should be at 106. It was at this point that I noticed that it had lost some coolant (overflow was down about 2 inches). Sure enough, there was also some on the garage floor too. It looks like I was too timid about tightening the water pump bolts. I imagine that most of the coolant was lost during driving due to the higher pressures that would have been present.

I hope to find an hour or two one night this week to tighten the water pump bolts. I am not sure if I can do it this time without draining the coolant or not. If I do need to drain coolant, I'll remove the pump again and see if I can find any more debris in that area.

I hope that the low coolant was the problem and not that there is another blockage in the system.

So here' my question for the forum this time -- would a 2 inch coolant drop (as seen at the overflow) cause this kind of overheating?

 

Glad you seem to have found the problem! I hope it all gets sorted quickly!

 

Thats the broken inner piece off the t stat housing i was talking about earlier. Its probobly the only piece as they tend to get stuck in the wp cavity where you found it impeeding flow. As far as the coolant level you had/have trapped air. I always like to run the car after a repair like this then let sit overnight and cool and top the reservoiir back up.

 

When I did the work earlier, I reused all of the fluid and didn't lose any material amount. That's why I don't think I had an air pocket.

I checked the overflow tank this morning. While it was down 2 inches when hot, it was only about 1 inch down when cold. I topped it to the max line and we'll see how much it leaks. I'm trying to determine if I should go to the effort of getting access to tighten the bolts, or if it will be futile. Seems like a minor amount of fluid loss to cause overheating.

 

It looks like you've done your homework. It would seem the only thing left is the radiator. I also have an o7 XK and a 1-2 in drop in coolant will not cause that overheating issue. As I've not had to look into it I don't know if the radiator can be boiled out at your local shop. That being said the price of radiators (for most cars) is inexpensive. Napa should be able to handle it.

 

I'd be mildly surprised if the rad plugged up at 40k unless something found its way to it (however, I'll settle for any correct diagnosis at this point). The coolant looks good, and when I drained it I filtered and found nothing -- doesn't really sound like a plugged rad. If it was plugged, it would appear that someone replaced the coolant (and maybe didn't solve whatever problem the rad had?)

Once heated up, I noticed that the top rad hose was hot and bottom one was cool. Does this mean that the rad is doing its job?

With the cracked thermostat I had, where else could the debris end up? I found one piece down by the water pump. Is it possible that something could end up elsewhere, like deeper in the engine?

When I idled the car for 20 minutes, the engine warmed up (quite slowly) to 95. The AC was on. I then flipped on the heater to full and the temp dropped quite quickly to 85. It seems that the heater matrix is working - not sure if this means anything else?

Lastly, At what temperature would you expect an idling xk to 'level out' at? I think that the thermostat opens between 80 and 95? Does this mean that this is where you'd expect the engine to be if not driven hard?

Sorry for all the questions -- I'm learning as I go here!

 

Progress! And a request for advice...

I had tried removing the water pump a second time to see if another piece of plastic had found its way down there, but found nothing. The car was still overheating, but at least much less quickly and more easily 'fixed' if I revved the engine at 2000 rpm.

Took it to another shop. They did a rad flush with no effect. Then they started taking it apart. Despite my having paid a Jag dealer nearly $500 the first time I had it in, it turns out that they didn't replace the entire thermostat housing. They said it was cracked, but only replaced the upper cap. This new shop found that the lower part was also cracked badly. Part has been ordered, and for good measure I've asked them to do a backflush of the block.

I've asked them to bag the defective parts. Should I take this up with the original dealer who obviously didn't replace the housing properly? Costs were $60 coolant, $87.05 for gaskets, $70 for housing, $135 diagnostics (pressure test I think), and $270 for 2 hours labour. Seems like a ton of bills to have half a job done, and it really threw me off "diagnostic wise" as the one thing I relied on being right was the thermostat and housing!