Water pump confusion
 

I don't know if the water pump on my early 97 xk8 (10/96) has been changed, so when I install the aluminum thermostat housing I will replace it. The many parts suppliers referenced on the forum list at least ten different pumps ranging from $41 to $123, all of which are supposed to fit my car. At least one dealer has a OEM pump and specifies that only yellow Jaguar coolant be used to prevent damage to the pump.
I would appreciate some input from members who have replaced pumps, but note that I am NOT trying to start another discussion on antifreeze.
Thanks, RJ

I've changed a few Jaguar V8 water pumps and none of them had broken impellers! The problem pumps seem to be the early ones and your '97 is in the build period of those most liable to failure. Like you, replacement of a 15 year old pump is a precaution I'd certainly be taking.

There's no reason why any of the available pumps wouldn't fit although $41 sounds just too good to be true. The manufacturing quality could be marginal. I've used both OE Jaguar replacement and mid range aftermarket pumps and never had any issue with fit or subsequent performance. You know exactly what you're getting if you purchase an OE Jaguar pump but an aftermarket one from a reliable supplier will be equally satisfactory.

I'm longing to comment on the reason for using Jaguar yellow coolant but will respect your prohibition. :icon_lol:

Graham

Didn't I read on this forum that we are supposed to use those and avoid the plastic impellers? Or, one specific color of impeller?

I want to hear the chemistry and physics of why the yellow Jag fluid is any better at protecting the water pump. :icon_saywhat:

Graham, maybe I was being a little hasty when I asked that no one comment on the yellow jag coolant. Considering your experience, I think your views on the topic would be of great value. Please proceed.

I think it was Brutal posted recently about avoiding metal impellers and now Avos has done the same.

As far as I can remember the reason is the metal type wear more quickly than the plastic type.

I've changed a few pumps on V8's and impeller colour isn't a reliable guide. There's many aftermarket sources for pumps and the impellers can be orange, black or white.

Graham

The oem plastic impeller pumps from 1998 forwards are good! They have been used until 2009 (last 4.2 engine). Only if your vin is pre 028000 you need to check your pump, if it has 96JV-8501-CA, CB, CC or CD, you need to change it (see TSB x303-60).

Some have reported that the aftermarket metal impeller ones (think these are for the Lincoln LS) where prone to leaking.

If you want to use a metal impeller one, you need to use a coolant that has cavitation inhibitors like silicon to ensure a long life, but I can’t see the point in going for a metal impeller as such as the oem ones are good (and certainly not as you also need a flush and change to a different coolant).

It's not that the colour yellow has magical properties!

Long gone are the days when we added 'AntiFreeze' to prevent frost damage in winter, now replaced by all year 'Coolant', a chemical soup with all kinds of inhibitors to prevent problems in aluminium engines as well as greater low temperature protection.

The issue comes with compatability. For years ethlyene glycol was the commonest component in AntiFreeze. If this is mixed with the current generation of OAT Coolants (such as Jaguar yellow), a sludge can form which blocks the system.

When changing coolant, it's good practice to flush the system anyway but this is even more important if changing from the old MEG type to OAT coolant. It's also a good plan to use distilled or de-ionised water in the 50:50 mix rather than tap water.

Graham

Great info Avos :icon_clapclap:

I hadn't seen the TSB identifying the exact range of affected pumps. Here it is for anyone else who may not have found it:

Attachment 19198

The impellar colour applies to Jaguar OE pumps but unfortunatley not to aftermarket ones where colour seems to be a fashion statement and not a design indicator. :icon_lol:

Graham

The oem plastic impeller pumps from 1998 forwards are good! They have been used until 2009 (last 4.2 engine). Only if your vin is pre 028000 you need to check your pump, if it has 96JV-8501-CA, CB, CC or CD, you need to change it (see TSB x303-60).



When it says VIN 28000, what VIN are they talking about?

Vin 028000 not 28000 (or A28000, which is also way past 1998)

It's from VIN 028001-on

That means the last six digits in the VIN string. Later model XK8's start the last six with an 'A'.

Graham

Thanks Graham. That was confusing. My number is A with five numbers following. I think I'll leave well enough alone. If it ain't broke don'g fix it.

EZDriver 2000 XK8

And it still is. It is the rest of the components that differ.

70:30, not 50:50 is the most effective for both freezing and boilover protection.

The strategy for filling after flushing is to add full strength coolant to the system if the drain method was through the radiator drains without using the block drains. This is because with the remaining water in the system, adding pre-mix will result in a final ratio much lower than 50:50.

In fact, adding straight coolant to the system, one will be hard pressed to achieve 50:50, much less 70:30.