maybe the connection got soaked in coolant and needs to dry off

 

The plugs are directly behind the TB.

 

OK I managed to pull out the two connectors for the left and right hand side pre cat sensors.



Next I measured the resistance between the two sets of silver and gold pins. Both sets of gold pins read open circuit (the sensor) and on the right bank (the good side) the silver pins were about 3 ohms but the left bank (bad side) was open circuit.



I tried swapping the connectors over to see if the fault code followed the sensor, it did, the fault code changed to P1646 and the back to P1647 when I put it back to stock.

The conclusion is the sensor has gone bad or the wiring has gone open circuit, either way I will go for a new sensor.

Any issue going with this one at half the price of the jag item?

NEW Oxygen Lambda lambada heated 4 wire O2 sensor,1yr warranty,next day delivery | eBay

 

A great guide.
Added to HOW TO thread.

Graham

 

I am in the install phase of a complete hose replacement. This thread was most helpful, but NOTHING can reduce the the PITA that this project is! The air condition hose and those friggin' Instrumounts are the biggest pains of all. I can't imagine what the labor costs of this would be if I'd brought it to a shop, or God-forbid, ... the Dealer!

NOTE: To add to the great advice given here, I offer the following: These aren't part of the manual's instruction, but at least for the 4.2 XKRs, take the EGR valve off the throttle elbow before undoing the elbow - this will make getting the elbow out effortless. And take the MAP sensor off the elbow before trying to unbolt the elbow from the supercharger - this will make getting to the lower left bolt much easier.

My thanks to everyone who's posted here.

 

I wish I had read this entire thread before removing my water ctl valve. BUT, let me throw out a tip I found about removing hoses from the male end that works great. Maybe this is common knowledge but it wasn't to me.

Instead of PULLING on the hose, you have to PUSH it off. So take a screwdriver or any prising device you can fit in there, and push the end of the hose away. Works like a charm, even if you can't get on it very well.

Apparently when you PULL on it, the hose tightens its grip on the male end. When you PUSH that doesn't happen. I've been parting my car and pulling hoses off is the worst. Tried the PUSH method, and pretty slick and it doesn't feel like you have to go full Godzilla on the thing.

Hope this helps someone!

 

I realize I'm late to the party but thought I'd add this for future readers. These pliers are intended for vacuum hose removal but I use them whenever I can (have had them for years.) Work fine for most heater hoses on plastic nipples, they normally just need a nudge to break them loose then come off quite easily. Most every tool dealer carries them. If you're having difficulty finding pair use Google Image or search "vacuum hose pliers".

 

There are indeed a couple things that will make this process go much smoother, AND increase the access to the valve and pump. You know that coolant tank bracket you show in the removal process pictures? It's held on with two bolts, 1) Remove the top bolt completely, be very careful not to drop it into oblivion, 2) Loosen the bottom bolt but don't remove it as it's a slip fit bracket. Take that bracket off and you just gave yourself a LOT more room to work with. (You may need a wobble extension to access the bottom bolt depending on the extent of your personal dissaembly preference)

In addition, buy some long reach hose removal pliers to simplify hose removal. You've seen them, they are the odd looking pliers with the hooked ends that allow gripping onto the hose to twist the hose and break it free

 

Good timing for a thread resurrection. I'll be diving into this monstrosity this week.

 

I've seen (and own), many, many pliers, but I've never encountered those long reach hose pliers before. Yup - definitely "odd", but I can see where they'd be incredibly useful (lower radiator hose, perhaps? Or some of the supercharger heat exchanger menagerie?).

Thanks Marvin!

 

Are you sure it has failed? I have had no-heat conditions 2 times in the last 2 years, and both times it resolved with a core flush. Somehow. These parts (pump, valve) are so expensive and hard to reach, the diagnostic needs to be on point...

 

Harbor Freight has a cheap set. Pep Boys, too, I believe. And yes, unbelievably useful for anything hose-related.

 

I'm in the same boat it appears. I was pretty much assuming the brushes on the heater pump motor were gone, but before I dive in, may I ask fmertz, how did you do the flush ?
Any chemical flush stuff ? This might sound elementary, since I've done it dozens of times on older cars, but maybe I could use a brush-up. Also, did you get the radiator petcock
open, or just pull the bottom hose ? TIA.

 

Well, start by checking that the motor has some resistance (a few Ohms, not "infinity"). You can do that from the relay connection. Top left side of the T.

Then do a shunt wire at the relay position to power the pump. You should be able to hear it run, but it is faint.

The heater valve defaults open, so you can disconnect it at the firewall to make sure there is flow.

For the flush, I did just the heater. You have to get stuff out of the way for access to the 2 pipes off the firewall, kind of behind the brake booster. You have to remove the 2 hoses. Just clamps, then easy twist/pull with these long hose pliers. I then used a few feet of clear plastic tubing, 5/8" i.d. from memory. Split the hose in 2, one, say, 2 feet, and then the rest. On the short tube, put a barbed/garden hose adapter for supply from your garden hose, the other long hose for a drain. Then use the garden hose to supply clean water under pressure. The drain will show what comes out. I did not see anything spectacular, no ha-ha moment, really. I then used standard radiator cleaner poured through the supply hose, and left it there 10 min. Then I flushed it. I then swapped the hoses for a back flush just because I was already there. Make sure you disconnect the hose on the supply side at the end so the drain side can siphon-off the remaining water off the heater core. Then put everything back together. Pump the radiator hose by hand to help refill. After that, there was heat in the cabin in less than a minute after starting the engine. Not super hot air, but some heat you can definitely feel. Not completely clear why, but this has worked perfectly for me.

Best of luck, keep us posted.

 

My heater went from working great to not working at all overnight, so I doubt a flush is going to resolve anything.

I will be getting methodical with it to make sure the diagnosis is correct. Besides that, I've needed an excuse to do the valley hoses, and the degree of extra teardown is pretty minimal.

 

This is how i removed my heater pump on my 1999

Link JagRepair.com - Jaguar Repair Information Resource

 

You can get them through various auto parts stores websites. I got mine at harbor freight tools and their extremely useful.

 

There is a fuse, too, dedicated to the pump. Easy to check first.

 

That does sound more like a problem with the pump than a clogged heater core.


I've had excellent results cleaning heater cores with CLR (Calcium Lime Rust), available in the kitchen and home cleaning supply areas of grocery stores, Walmarts, etc. With a hose setup similar to that described by fmertz, I first blow all of the water/coolant out of the heater core with compressed air. Then I tie both hoses up to the hood/bonnet with string to keep their ends high so the cleaner won't drain right out of the heater core. If your hood struts are weak, use a prop stick to support it. I put a funnel in the end of one hose and pour about 1/2 bottle of CLR into the hose so it can make its way into the heater core. Allow to sit for 30 minutes and flush with clear water, taking care to keep the CLR away from any painted surfaces. Then I blow out the heater core with compressed air again and repeat the CLR application. This has cleaned every core I've ever tried it on, but YMMV. CLR is not recommended for use on aluminum or brass, so I am careful to not let it soak for more than 30 minutes. Use at your own risk.

Cheers,

Don

 

I picked up a cheap (~$20) mechanics stethoscope off Amazon, so I gave it a try on the heater pump, and I'm pretty sure I could hear it running. The stethoscope has a long metal probe fortunately, so was able to at least touch it to the pump bracket. So, I ordered some of those long reach hose pliers from Harbor Freight (~$20), and some CLR stuff - is this forum great, or what ? So, when I get my stuff together, I'll give the flush a shot. Sounds so much easier than digging for the pump.