Howdy, Jon

Any help here ? ...
https://www.jaguarforums.com/forum/x...-pliers-77985/

 

Bingo! Thanks, Dennis!

Now I can practice on them. Even if they do properly open and close without deformation, it may make sense to replace them with good ol' screw-type worm-drive clamps. Do you guys agree, or is that too much potential pressure on the plastic nozzles?

 

If I could not get the clamp NORMA off without damaging it, I replaced with same from dealer. If it came off like the pics in the link above then i would reuse.

 

The little clamps need to be squeezed with a pair of pliers . . . gently . . . to unlatch the clamp and pried apart with a very small screwdriver or awl.

As far as bending over to work on this car why not jack it up to whatever height if comfortable. When working on the pick up truck I take the front tires off and lower it on the jack to eliminate the need for a stool to get over the fender.

 

Thanks again to all who have contributed in this thread. I believe I now have all the various tools I'll need for this job. Tomorrow may be the day. We'll see....

We're off to Pinehurst for our annual feast in about an hour. Happy Thanksgiving to all....

 

Update:

Done. I ran into a couple of problems. The biggest one was the fact that the coolant temperature sensor plastic clip on the wiring harness snapped off in my hand as I removed it. Age and heat cycles made that plastic clip extremely weak. I used electrical tape to hold the sensor plastic clip body into the new sensor. Any suggestions on a better way? I doubt if Jaguar sells just these plastic clips because you would have to remove the old one from the wiring harness and that would involve cutting wires, resoldering them, etc....

The second problem was the fact that the plastic hose running from the coolant expansion tank to the top of the coolant outlet pipe was also brittle and cracked when I pulled it off the coolant outlet pipe. I replaced it with a section of 5/16-inch fuel hose and two worm-drive clamps I purchased from Advance Auto Parts. The new hose is much more robust and I don't care what it looks like because it will be hidden by the engine dust cover....

The eight bolts that hold the coolant outlet pipe in place were all Torx T-30. I could not get to the two rear bolts on the bypass to water pump section until I removed the manifold front plate. Four 8mm hex bolts hold that plate on. When I took it off, I also pulled out its old gasket and replaced it with a new gasket. The old gasket was cooked in place pretty tightly. I used my needle-nose pliers and some careful tugging with my fingers to get the old gasket out. It came out completely intact so I was lucky there....

Once I had the front plate off, I could get my 1/4-inch drive Torx T-30 bit and 6-inch extension on those two rear bolts. It was very tight, but I took my time and managed without dropping any bolts. I had placed an old rag directly underneath that area to catch any bolts in case I fumbled them....

When I finally had all of the old plastic coolant outlet pipe components off the engine, I cleaned all mounting surfaces up to bright-and-shiny status before installing the new components. No sandpaper, just a clean rag and plenty of elbow grease....

Before I started this job, I thought about how I would drain the cooling system low enough to where the remaining coolant level would be below the bottom of the bypass to water pump section. I knew if I could get it that low, coolant spillage would be minimal. So I pumped out the coolant expansion tank, removed the small hose running between the coolant expansion tank and the top of the coolant outlet pipe, and then pulled the heater core hose off the back of the old plastic assembly. I had placed an old towel underneath that area before pulling that hose, and I lost perhaps 10 to 12 ounces of coolant into the towel. I then forced my hand pump hose down that heater core hose and pumped until no more coolant came out. I used an empty gallon orange juice jug as my coolant catch basin. I then removed the two large radiator hoses at the front of the coolant outlet pipe and pumped each of them dry. I pumped out a total of right at a gallon of coolant from the four different areas I crammed my hand pump hose into. This coolant was still bright orange and very clean, so once I had the new parts in place and the hoses properly attached and clamped, I poured that captured coolant back into the system to refill it. I had to add about a quart or so of fresh coolant in order to fill the coolant expansion tank back up to the bottom of its filler neck, which is where I typically keep it....

Once finished I cranked up the engine and let it run for about ten minutes with the cabin heat set to HIGH and the cabin blower set to MAX while watching for any leaks. I saw none. So I took the car for a ten-mile test drive. No dash lights, no warning messages, and the coolant temperature gauge sat right in the middle of the dial where it typically does. I'll let the system cool overnight and check the level in the coolant expansion tank tomorrow morning. I expect to have to add a bit of coolant each morning for the next few days until the system finally burps all the air out....

Many thanks to all who contributed advice and recommendations in this thread. I could not have successfully performed this repair without your kind assistance....

If anyone has any suggestions about how to resolve the fatigued and now broken-off plastic clip that snugs the coolant temperature sensor harness onto the sensor itself, I would be much obliged. I don't know how well my electrical tape wrap will hold it given the heat it must endure....

 

Jon, so glad you got it done and things kind of went as expected. We know someone who will be happy.
Sorry about the connector, if you can get one from the dealer or cut one off at the junk yard, we can fix it up. The tape may not hold up, strips of duct tape may do until a better plan.
I keep watching all afternoon, hoping you who let us know and congratulations on a job well done.


Wayne

 

Use a 3 or 4 dabs of RTV to fasten the two connector shells. It will hold tight and be removable if you need to get it off in the future.

 

Isn't it great to work on your car, take it for a test drive . . . and get home!

Both my connector attachment tabs broke off also. Just hanging loose at the moment.

Without reading through 60 posts did your repair involve replacement of the temperature sensor? I just did and find that the brand new sensor is reporting temperature much higher than an IR temperature gauge is reading on the sensor itself.

 

test point,

A new temperature sensor comes already installed in the new coolant outlet duct from Jaguar. I have no idea how accurate or inaccurate these sensors are. The needle on the dashboard gauge still sits about halfway on the gauge once the car has done enough miles to bring the system up to temperature. But I know these factory gauges are little more than idiot lights....



Steve,

I like your suggestion to use a few dabs of RTV to hold the two plastic sensor shells in place now that the plastic retainer clip has broken off. I never would have thought of that. Thanks, Steve....

 

My new sensor delivered a resistance signal to the ECM that was 14*C higher than the IR temp gauge reading at the sensor.

Problem is that until TORQUE Pro the hobby mechanic never had a way to see this difference between expected and reported temp.

 

For those of you 4.2 engine owners facing this repair (own the car long enough and you will), here are the two Jaguar parts and part numbers you'll need:

1. Coolant outlet duct, part no. AJ89486. My local dealership's list price is $147 plus tax. They offered it to me for $115 plus tax.

2. Manifold front seal, part no. AJ87991. My local dealership's list price is $9 plus tax. They offered it to me for $4.50 plus tax.

The parts guys at my local dealership acknowledged that they sell both of these parts like candy so they keep a fairly hefty supply in stock....

I suppose we'll never see an aftermarket aluminum coolant outlet duct like you 4.0 engine owners have available to you. The XK8/XKR was probably already planned for its end-of-production by the time the 4.2 took over, so the numbers just aren't high enough....

 

Well done, Jon.

Questions: What was the condition of the plastic components you removed? What's the mileage on your car?

I'm sort of second-guessing myself about not replacing the whole assembly, but I go back and forth on this. I replaced just the thermostat and seal at ~ 45k miles. The seal had begun to leak. The plastic bits all looked fine (can we tell by looking?) and I come back to the fact that the plastic tower on my '01 (said to be of inferior plastic) made it to 90k miles. At least I think it did; it might have been changed before I got the car at ~ 30k mi., but no record of it. Surely an exception if it did make it that far.

Do we have anything like an expected lifetime for the plastic bits in the 03+ ?

 

Dennis,

The original plastic components I removed definitely showed their age when compared to the new plastic components I installed. I did not see hairline cracks or pitted surfaces, but age and heat cycles had definitely lightened the color and made the edges more brittle. The dealership parts guys told me that these pieces tend to warp slightly as the heat cycles torture them over the years, warpage eventually leads to seam gaps, and then your leak(s) manifests and gradually worsens over time. My leak probably started a month or so ago. I never saw it or smelled it. Only the marginal decreases in the coolant expansion tank fluid level during the past few weeks told me that something was wrong. The minute amount of coolant that escaped was instantly vaporized by the engine heat, leaving no trace that I could see. The pressure test kit loaned from Advance Auto Parts last Sunday morning exposed the leak (and enlarged it in the process). The car stayed parked until I sourced the parts and tools needed for the repair, then I had to wait for the weather to clear in order to do the job the way I wanted to do it....

The car's mileage was 85,541 on the day of the repair....

Regarding your question concerning the expected life of these components, we all know what happens to the plastics in our Jaguar engine bays. Jaguar plastic is far more susceptible to age and heat failure than any other vehicle brand I've ever owned and I've been driving since 1969. I believe that the plastics and the electronics in both of our Jaguars will be the culprits that eventually cause them to fail my cost/benefit analysis that I set up for every vehicle we bring into our stable. Once the vehicle becomes a money pit, it's gone. It either gets sold or donated to charity for a tax write-off. I will never become so attached to a vehicle that I completely disregard my economics training and continue to waste money attempting to keep it viable for our transportation purposes....

Your thermostat and seal replacement may hold up for awhile. But sooner or later that plastic coolant outlet duct is going to warp. When it does, you should replace the entire assembly. My advice is to check the fluid level in your coolant expansion tank at least a couple of times per week. If you don't catch these leaks quickly, the risk of losing your engine increases exponentially....

 

All good advice there, Jon. Thanks.

If my car's cooling system plastic makes it to 85-90k miles, I may escape doing this job. But by then it will probably be 16 years old or so. We'll see.

I was trained by the best (an MGA) to watch temperature gauges like a hawk. It's been reported that our stock gauge maps a wide range of temperatures to a single mid-scale reading, but I'm not sure this is exactly true. On my '01, when it was starting to develop leaks, I noted that there was very slight pointer movement (about the width of one hash mark on the gauge) when the coolant level was down a bit. This before I got a "coolant low" message. It told me enough to keep me out of trouble.

I don't know if my '03 would do the same, and hope never to find out.

 

The factory coolant gauge does indeed have a narrow 'analog' range above center scale. It can vary a bit between vehicles, but is typically over 235 F when it begins to rise and then within a space of an additional 3-4 degrees F rises from center scale to the red range. It is unrelated to coolant level, unless the level is low enough to cause excessively high operating temperature.

On other models (the X-type for example) the rise starts at a slightly lower temperature, offering up a bit more early warning.

 

Yes, I understand that the temp gauge can't sense coolant level directly. My interpretation was that the temperature was up somewhat, suggesting that there could be less coolant at work. This was the earliest warning I got, preceding a low-coolant message by 15 minutes or so of driving.

 

Update:

I expected to have to add coolant in stages after this repair as the system continues to burp any trapped air out. The repair was last Friday, and I drove the car about 10 miles afterwards. First thing Saturday morning I had to add perhaps 6 ounces of coolant. I then drove the car that same 10 miles. Yesterday morning I had to add perhaps 2 ounces of coolant. The car was not driven yesterday. So I'll drive it that same 10 miles today and then check the coolant level first thing tomorrow morning. I hope I'm almost done....

 

As I mentioned in a previous post, check your hoses while you're wrenching within the bowels of the engine. One of mine was quite severely bulged at one end and if it had gone, the results would have been catastrophic .. much more severe than just a "Low Coolant" warning.

Now the dealership price for the lower hose was about $170 .. perhaps you guys can do better .. I hope. But at 85k and 11 years old, better take a close look while you've got her opened up. While changing hoses may be a 100K service item, bear in mind that most daily drivers are at 100K long before their 11th birthday. '03 XK8 conv 85K. Cheers!

 

With the exception of the lousy plastic hose that runs between the coolant expansion tank and the top of the coolant outlet duct, all of the other hoses that I could get to looked and felt to be in decent shape. They re-clamped properly and thus far show no signs of any coolant leakage, but I know it is still much too soon after the repairs to declare victory. I left the engine dust cover off for the time being so I can have frequent looks and I will continue to check the coolant expansion tank fluid level every morning for at least the next couple of weeks. Better safe than sorry....

My wife is very happy to be back in her XK8 as of this morning. We'll see how it goes....