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So I was going to reinstall the water pump on my 2000 XJR and I pulled out the new gasket that I had ordered awhile back. It was only then that I noticed my gasket did not match the shape of my water pump. I was annoyed but figured I had just ordered the wrong part by mistake. The part I ordered was part no AJ83300 which is listed as fitting my car, the other part number listed is AJ88922, but when searching for that part I find it is the same shape as the gasket I already have. It seems every gasket I search for this car is this shape.
Below is a picture of my water pump, and a picture of the engine block where the water pump goes. The old gasket I took off matches this shape:
And here is a picture of my new gasket:
Why can't I seem to find a water pump of a water pump gasket that matches what came off my car??? Does anyone have a part number for it? Every part number I can find seems to be the wrong shape.
Is that even the correct water pump? Does the new gasket you have pictured line up with the mounting holes on the block? The gasket itself looks correct. The gasket you have is exactly what I used on my 2002 XJR but the back of my water pump looks completely different.
It looks like there were several different original part numbers based on VIN and engine number but they ALL seem to have been superseded by one single replacement part number - AJ88912 for the water pump and AJ88922 for the gasket.
Is that even the correct water pump? Does the new gasket you have pictured line up with the mounting holes on the block? The gasket itself looks correct. The gasket you have is exactly what I used on my 2002 XJR but the back of my water pump looks completely different.
It looks like there were several different original part numbers based on VIN and engine number but they ALL seem to have been superseded by one single replacement part number - AJ88912
I'm pretty sure its the correct water pump, because it matches exactly with the engine block. The new gasket lines up with the holes on the block but the shape is completely wrong and it covers two of the holes. I've put a picture below.
I'm searched all the old part numbers as well and the one for every vin or engine number, they all seem to be the same shape as the gasket I have.
Also here is a picture of the old gasket, it matches the pump I have and the engine block:
I'm pretty sure its the correct water pump, because it matches exactly with the engine block. The new gasket lines up with the holes on the block but the shape is completely wrong and it covers two of the holes. I've put a picture below.
The water pump has two gaskets: one between the pump halves which is not separately available (the old black gasket you have shown) and another between the pump assembly and the engine block. You have not actually removed the complete pump assembly from the engine block but just separated the pump outer half from its inner half where the special gasket sits. If you pull out the half of the pump remaining attached to the block, you will find the gasket AJ88922 where your new aftermarket gasket will fit. The two pump halves are normally not separated, except for pump rebuilds. Once you have pulled the inner half of the pump out, join back the two pump halves using the old black gasket and some sealant on it. The two pump halves are held together by two short bolts (which you should not have removed), where shown on the pic by red circles. I have painted the heads of these two bolts red so that I do not accidentally undo them next time.
Otherwise, the genuine AJ88922 gasket looks like this:
The water pump has two gaskets: one between the pump halves which is not separately available (the old black gasket you have shown) and another between the pump assembly and the engine block. You have not actually removed the complete pump assembly from the engine block but just separated the pump outer half from its inner half where the special gasket sits. If you pull out the half of the pump remaining attached to the block, you will find the gasket AJ88922 where your new aftermarket gasket will fit. The two pump halves are normally not separated, except for pump rebuilds. Once you have pulled the inner half of the pump out, join back the two pump halves using the old black gasket and some sealant on it. The two pump halves are held together by two short bolts (which you should not have removed), where shown on the pic by red circles. I have painted the heads of these two bolts red so that I do not accidentally undo them next time.
Otherwise, the genuine AJ88922 gasket looks like this:
If that gasket is not available am I stuck buying a new water pump?
If that gasket is not available am I stuck buying a new water pump?
The old gasket looks pretty good on the picture. Just clean it and clean the mating surfaces (do not scratch them) and assemble. You can use a very very thin coat of some liquid gasket sealant on it but it may not be necessary if the rubberised coating of the old (metal) gasket has no damages.
M. Stojanovic has nailed it! I can see it now; the part still on your block is what I see as the back of my water pump.
M. Stojanovic did in fact nail it. A few gental taps with a mallet and the other half of the water pump came off to reveal a matching gasket to the one I've ordered.
Originally Posted by M. Stojanovic
The old gasket looks pretty good on the picture. Just clean it and clean the mating surfaces (do not scratch them) and assemble. You can use a very very thin coat of some liquid gasket sealant on it but it may not be necessary if the rubberised coating of the old (metal) gasket has no damages.
I think I'm just going to order a new water pump for piece of mind. It was a coolant leak that lead to the overheating that brought down the car in the first place, I don't want to put it all back together only to find new leaks to solve.
But thanks for solving this one for me.
just ordered a new pump from Moss (XKS Unlimited) one with a metal impeller instead of a plastic one. Price was more than double some other ones online but knowing this one is metal instead of plastic, I think its worth the expense.
I have made that mistake. The new water pump leaked from day one. I guess I would have gone for a much cheaper AC Delco: The two halves are integral and the gasket that comes with it is a perfect fit. Never had a leak thereafter.
one more question, what's the deal with this o-ring pictures in this parts diagram? Part no AJ81324. where does it go? I'm assuming I'll need a new one of these if it doesn't come with the new water pump.
It seems that some engines had an o-ring for the water pump and some did not. There are two o-ring sizes, 55 and 70 mm, depending on the diameter of the round opening in the block. If used, the o-ring is placed at the opening of the engine block first, then goes the gasket then the pump. But. it seems that the o-ring was later omitted, probably with the revised gasket which has a sealing "rib" for the round opening in the block (see the pic of the genuine gasket I posted earlier). The old pump gasket on your engine was genuine and, if you did not find any o-ring there, that's how it goes (without o-ring). However, your new aftermarket gasket does not have any integrated rubberised seal around its big round hole so it will need an o-ring there. Alternatively, if there was no o-ring with your old genuine pump gasket, you can buy a new genuine gasket and assemble without any o-ring.
It seems that some engines had an o-ring for the water pump and some did not. There are two o-ring sizes, 55 and 70 mm, depending on the diameter of the round opening in the block. If used, the o-ring is placed at the opening of the engine block first, then goes the gasket then the pump. But. it seems that the o-ring was later omitted, probably with the revised gasket which has a sealing "rib" for the round opening in the block (see the pic of the genuine gasket I posted earlier). The old pump gasket on your engine was genuine and, if you did not find any o-ring there, that's how it goes (without o-ring). However, your new aftermarket gasket does not have any integrated rubberised seal around its big round hole so it will need an o-ring there. Alternatively, if there was no o-ring with your old genuine pump gasket, you can buy a new genuine gasket and assemble without any o-ring.
I'm not sure I'm completely understanding you. Are you say the new gasket I have is made to be used with an o-ring? And if there is no old o-ring in place on my motor then I need to order a different gasket, or alternatively order a o-ring???
I'm not sure I'm completely understanding you. Are you say the new gasket I have is made to be used with an o-ring? And if there is no old o-ring in place on my motor then I need to order a different gasket, or alternatively order a o-ring???
Yes, if there was no o-ring with your old (genuine Jaguar) gasket, then if you prefer to go without an o-ring, you should get a a new genuine gasket. Otherwise, if you wish to use the aftermarket gasket you got, you will need to use an o-ring with it. Sometimes new water pumps come with a gasket and an/or o-ring but you will have to see if they are included when you get the new pump. The XKS Unlimited state that their pump is "Supplied with a top-quality Cometic gasket" which may be the type which does not require an o-ring. On the other hand, they don't say whether the Cometic gasket they mentioned is the gasket already installed (between the two halves of the pump) or whether they supply, together with the pump, the gasket to go between the pump and the block so you will have to see what you get.
07-09-2019, 08:47 PM
Water pump question:
