No heat. Or not much heat

Michael,

Your experience, sadly, is not unlike mine as far as having anyone actually take the time to even consider looking at this pump to determine what was wrong with it and whether it could be repaired. That's so unfortunate because it looks like these things, other than their brushes, could probably last "virtually forever."

When I went looking for replacement brushes I'd already taken the motor apart and took only the brush nubs with me.

These motors can (as you now know) easily be repaired. For anyone reading this who wants to know how, see the link at the end of the post. Even if you have a later car the auxiliary coolant flow pumps are so similar, particularly at the "working end," that the repair should be very much the same.

After visiting several electric motor shops looking for brushes and every one of them refusing to even look at it, I pulled some brushes out of an old power window motor and used them. It worked and as far as I know is still working. The wife traded the XJ in on a new Jeep Grand Cherokee. No more oil and coolant drops on the garage floor. I can get used to that.

Howard,

Access to that silly pump is a pain, but it can be done. Here is a view and legend for the cooling pack and pumps.

Hope it helps!

Edited on 2013-07-07 16:17:54

Howard,

The attached image is straight out of JTIS (Jaguar Technical Information System). The auxiliary coolant flow pump is item #3. It looks almost precisely like the one on my 1999 XJ8L except it's been relocated to the front of the car rather than being mounted near to the firewall.

Here is an eBay listing for your auxiliary coolant flow pump (AKA, auxiliary heater pump or scavenger pump):
http://www.ebay.com/itm/2004-2005-2006-2007-JAGUAR-XJ8-XJ8L-VANDEN-PLAS-...

and here is one for the earlier version of the pump, like the one in my car:
http://www.ebay.com/itm/1998-2000-2003-JAGUAR-XJ8-XJR-VANDEN-PLAS-AUXILI...

As you can see, while they vary slightly in their details, overall it's pretty much the same beast.

When the brushes in my auxiliary coolant pump were starting to fail I'd get "on again, off again" heat. Some days it would work and others it would not, until one of the brushes was completely consumed. This is all documented in another thread on the MNC6710AC and repairing same.

Good luck with fixing yours. If you photo document the process please post what you find when you take things apart. This is a somewhat tedious job, but it's by no means difficult.

Steven

I suspect I am looking right at the pump, but don't see it. Should I be removing the coolant expansion tank, and leaving the hoses attached so that I can see the pump and work on it? I suspect the pump is bad, since on long drives in the winter heat is insufficient, but on short drives the heater performs much better. I appreciate any help you can provide.

Howard,

On your car the coolant pump for the heater is just to the left and straight down from the coolant expansion tank; as you look at it standing in front for the car with the bonnet open. It attaches to the fan shroud.

Cheers,

Howard,

I do not have JTIS in front of me at the moment, but my gut tells me that it's unlikely that this pump was relocated between 1999 and 2004. I'll double check later.

In my car it's located just in front of the firewall on the left side and is easily visible when you open the hood/bonnet.

Based on a quick eBay search for the part the auxiliary heat pump looks pretty much the same for the 2004s and later as it did for the earlier cars. Check the location I noted first. Even if it's in another location, it wouldn't surprise me if your issue is the same as the one I had, and documented the repair steps for:

http://jcna.com/forums/view.php?Vref=JCNA&Vfnum=170&Vthread=7890

I would appreciate some details on locating this circulator pump. I have a 2004 XJR.

thanks

Just checked out your pump motor pics. Looks fairly straight forward. As many times as I have rebuilt the power window motors in my '65 Thunderbird, this should be a breeze. Except the draining the coolant part. I always make a mess. Thanks!

Mike,

This task is not difficult at all. One thing I learned after doing this (see the thread I posted with pictures) is that you do *NOT* have to pull off the metal cap that's generally very well sealed to the impeller side of the pump. If you just take the two screws off that hold the motor on you can slide the entire housing off exposing the armature and the brush plate.

If at all possible, try to find brushes of the correct size. I had to buy somewhat larger ones. Though they can be sanded down pretty simply, it's still a tedious process.

Also, *beware* the three studs that the motor bracket bolts to. These are, for some bizarre reason, brass and are *very* easy to break if you overtighten the nuts even slightly. This is the voice of experience speaking.

Brian, who hasn't checked in for a while

I have found used pumps for a hundred bucks or so. New ones are 4 to 5 hundred. May just take mine apart and clean it up.

I have done some research in other forums and believe the electric water pump is the likely culprit. Apparently the brushes can be cleaned out and reassembled, and the replacement part can be found for about $100.

I have done some research in other forums and believe the electric water pump is the likely culprit. Apparently the brushes can be cleaned out and reassembled, and the replacement part can be found for about $100.

Yes.

Is the coolant topped off?