1991 Jaguar XJ-S

[AKROVER]

My touchup kit arrived today, and I spent an hour fixing my mistakes from last week and touching up a few other edges. I also did a little more polishing. The best approach appears to be wet sanding with 1500 and then using polishing compound. At this point, the couple of spots that I originally described as failing the 10-foot test are now passing down to about 5 feet. It looks a lot better. There are still a few other spots that I think could clean up better. This will be an ongoing effort. My results are satisfying me. I am no longer contemplating taking this to a pro. I do need to attack the rust spots, one on the passenger door, one on the passenger wheel well, and the underneath edges of the trunk lid. For that, I will need to get some spray touchup, but prep and priming will be the first steps.

[AKROVER]

I have a squeak that repeats proportional to vehicle speed. It sounds a little like a cricket. The squeak vanishes with just the lightest touch of the brake pedal. It isn’t always there, but it is annoying when it shows up. Yesterday, I pulled each front and inspected the brakes because I thought the sound was coming from the front. It is all good there. I then jacked up the rear, put the car in neutral, and rotated the wheels. I could hear a squeak, but I couldn’t really isolate it. I can’t seem to identify where the sound is coming from. I thought it might be one of the u-joint covers on the axle shafts, but playing with those didn’t change anything. It is probably just one of the new brake pads, but it is annoying. I will probably need to crawl under further to find the culprit which will require putting the car on stands.

I have also continued trying to fix up the paint. I now think I understand what has been touched up, what has been re-sprayed, and what is original. I also have figured out how to reduce the appearance of the seams of the touchup spots. The driver quarter has been re-sprayed with a blend line at the top of the c-pillar buttress. It left an edge of what I think was clear coat, but I was able to sand that off and then polish the seam so that it looks a lot better (far from perfect). There was also a touchup right behind the driver’s door that I sanded and polished which better hid the seams. The original paint has some imperfections that look like water spots, but those don’t seem to come out no matter how much I polish. I keep flirting with disaster with wet sanding and polishing, but so far I haven’t gone through the color, other than my overly aggressive effort a couple weeks ago. With the touchup paint, I am really learning the importance of thickness. If I get the primer too thick, when I try to even out the color, I burn through the color. It seems to be an iterative process. At some point I just need to stop as it will never be perfect, but it is an amusing way to pass time in the garage with my car.

I continue to drive it regularly. I am just a few miles from 48K so I will have to watch to see if my odometer makes the turn this thousand. Since the IRS went back in, my last couple tanks of gas seemed to deliver better mileage, but my data isn’t precise enough to be sure as I never fill the tank. It looks like the last two tanks were pretty close to 15mpg, bringing my total ownership up to 13.7 mpg. With the fuel tank back to its target three quarter full, I also measured the rear bumper height, and it hasn’t changed at all, still 22.5”. Prior to pumping gas the other day, it had actually climbed over a quarter inch due to the low tank level. This means that I could use bumper height as a fuel gauge.

[AKROVER]

I bought a cheap accessory for the Jaguar, a Bluetooth cassette tape adapter that allows me to play music from my phone through the car stereo. It works surprisingly well. I wouldn’t describe the sound quality as great, but I don’t think the phone delivers great sound quality to my other cars, either. I was surprised that the sound seems very clean. I was almost expecting some analog pops and hiss, but I was also expecting that my stereo had a potentiometer issue that was causing some intermittent sound. It turns out that my problems with the car stereo have been entirely radio reception, which shouldn’t be too surprising given our near lack of radio stations and the hills and valleys that block the signals. The stereo in the Jaguar seems to be a decent unit. The adapter does have wheels that turn so there is that classic motor/mechanical sound of a cassette player when the music fades out.

[AKROVER]

Today was the first time I did any work on the car in over two months. The car has been driven regularly and mostly is running great. The squeaky brake problem still hasn’t gone away. With music in the car now, the squeak is almost not an issue, but I don’t always want loud music in the car, and it is embarrassing squeaking my way through downtown where many people recognize my car. I did some research, and I am pretty sure that I simply have brake pads vibrating and making noises when they are not being compressed. The general recommendation is to put some lubricant on the contact points of the pad (slides and piston, obviously not rotor). Since the pads are relatively easy to pull, I decided to try it. I jacked up the rear, put it on stands, and crawled under. I probably didn’t jack it up high enough, so it was quite awkward, but I was able to remove the pins that retain the pads and then pry and slide the pads out. The recommended lubricant is a copper-based lubricant, essentially anti-seize, but none of the local stores had it so I decided to just use my existing aluminum-based compound on the back of the pads where the piston hits. It made a big difference, but I still have a squeak when moving very slowly after driving for a while. I lubricated the pins, too, but those really are more of retaining pins than slides. I think the pads are guided by the caliper body itself, so I am now wondering if the remaining squeak is from contact along the edge of the metal backing of the pads. I might be able to lubricate those edges, but it is hard working under there without making a mess.

The car has now been in my possession for over a year. I have put on over 1800 miles. I have averaged 13.8 mpg, but the last three tanks have been 15.1. That is since the major work on the IRS, so perhaps I had a brake dragging previously. I also know I had a fuel leak for the first month of ownership and the first three times I pumped gas averaged only 13.3mpg. So far, I have spent $507 on fuel and $2288 in parts. It is amazing to look back at all the work I have done on this car (185 hours of garage time). It is also nice to be in a period of primarily just driving it. I am sure the next problem is just around the corner, but in a way, I look forward to that, too.

We drove the Jag to dinner on Thursday and it was pretty cold when we headed home. It was the first time I was sure it was below the 59-degree cabin temperature required to permit the seat heaters to work. I heard relays click when the switches were hit and the lights on both switches came on. It wasn’t at all like a modern seat heater putting me on broil, but I am pretty sure both were working on the short drive home as we both were feeling warmth both on the back and the seat. Hardly an important feature in a classic car, but good to know they still work.

[MostMint]

Random questions on the brake noise:

Since the brake noise is when moving slowly, will it do it at walking speed? Just wondering if hearing it from the outside might help you isolate where its coming from.

Is it any different when you turn?

Are you certain this is not a wheel bearing issue?

Does this car have ABS? Where is the sensor?

Have you tried a different set of pads? I'm wondering if there is some hard spot in the pad that may drag just a bit on a high spot on the rotor.

[AKROVER]

Random questions on the brake noise:

Since the brake noise is when moving slowly, will it do it at walking speed? Just wondering if hearing it from the outside might help you isolate where its coming from.

Is it any different when you turn?

Are you certain this is not a wheel bearing issue?

Does this car have ABS? Where is the sensor?

Have you tried a different set of pads? I'm wondering if there is some hard spot in the pad that may drag just a bit on a high spot on the rotor.

I actually don't know if it will make the noise at walking speed. With my slightly elevated idle, I am not even sure the car can go at a walking speed without riding the brake (which completely silences the noise). I am actually curious what it would even sound like at such a low speed. I will see if I can find an empty parking lot the next time it is squeaking.

The noise doesn't seem to care about turning.

I am not certain that this is not a wheel bearing issue, but the noise always disappears with just the lightest touch of the brake pedal (light enough not to even feel any braking). I don't think a wheel bearing would respond that way.

The car does have ABS, and the sensors are mounted into the side of the outboard bearing housings that hang on the ends of the IRS.

I do not have an extra set of pads to try.

I drove it again today and the one thing that has clearly changed since lubricating the back of the pads is that the noise now goes away at higher speeds. It used to just chirp faster and at a higher pitch. The car never seems to squeak at the start of my drive. It always seems to be squeaking when I get back into town which in most drives is after a long downhill with dropping speed limits, so moderate brake use seems to cause the problem to occur, as if it were thermally related.

[MostMint]

Slight grade and roll in neutral if the engine idle is too high.

With the Lacrosse the inners of the hub (where the ABS sensor components are) were quite rusted and I'm pretty sure that was the cause of the noise there. The Jaguar ABS setup is probably completely different, but that was why I was asking about the ABS sensor.

I wonder if there is a hard spot in the pad material or a rotor that expands when warmed up that could be causing this. Long shots I know - just something to consider, and why I was asking about other pads.

If it's only doing it on one side you could switch the pads from side to side and see where the sound goes.

[GMJohnny]

I’m not certain what the configuration of the pads is, but I’ve always used a grinder
to open the slot on the pads to add a bit of slop to the action. I’ve done this ever since
I had a squeaky set and the grinding cured the issue. Just a thought.

GM

[AKROVER]

The cricket has been squashed. It was a squeaky brake pad.

I kept contemplating how to pinpoint the precise source of the sound. Last night, I even experimented with driving at a walking pace in the longest local parking lot, trying to imagine my instructions to my wife on how to drive slowly without hitting the brake pedal. I was also imagining my own contribution of trying to pinpoint by ear the source of the sound. Left and right wouldn’t be easy to determine when the rear brakes are near the center of the car. I thought about getting the brakes warmed up to their squeaking condition and then quickly driving home to put the car up on a jack so I could hand turn the wheels and perhaps locate the squeak. This afternoon, I found myself mentally obsessed with the edges of the pads. While I lubricated the contact points with the piston, those edges of the pad backing plate had to be a direct metal-to-metal contact with the housing of the caliper and a potential source of the sound. I decided that if I jacked the car up a bit higher this time, I could probably work quickly without as much struggle as the pads really are easy to pull. It took just a half hour from start to finish, including putting the tools away. This would have been so much easier on a lift. Jaguar never considered future owners working in a home garage.

My plan was simply to pull the pads, lubricate the edges, and install them in the opposite location from where they came out, figuring that both lubrication and position swap had a good chance of solving the problem. When I pulled the second pad on the driver’s side, I began applying a light coating of lubrication on the edges. The first thing I noticed is that the edges are not exactly smooth. The second thing I noticed was a bit of a burr that was smooth and shiny, a clear rub point. When I saw that, I was pretty sure I had found the problem. I thought about taking a file to that edge, but I figured swapping was going to change the edge of greatest contact anyway (in other words, I was too lazy to crawl out from underneath the car). The other three pads had no similar burrs, but the edges are certainly not machined to a bearing-quality smoothness.

The test drive was such a relief. The squeak is gone, even after braking from 70 to 25 on the downhill coming back into town. Of course, driving around in a 35-year-old car with the music off while listening intently for odd sounds is never a completely positive experience. Next annoying sound on my list appears to be the HVAC fan motor. I suppose the other option is to download a heavy metal playlist and just enjoy the drive.