Prudence, my 87 Town Car

[Lutrova]

I did pull the plugs last summer, I think, and found some evidence of fouling on the back cylinders. If I check them again then I'll probably just throw the new ones in since they're ready to go. Wires could also be trouble. I've replaced one or two from the connection breaking after I pulled them. Maybe another is getting loose or otherwise not seating right.

On the suspension, all the rubber is fresh on that front right side except for the lower control arm bushings, which are shot. But I would expect those to make more of a clunk than a lighter rattle. Brake hardware also looks to be good, and the wheel covers are tight. It still rattles even with the wheel covers off, so that's not it.

I should've said with the paint that it's single stage. I've compounded and polished the hood before and the pads turn black, so there's no clear. Whatever they repainted it with is on the soft side. I should probably figure out what kind it is so I can match with the touch-up.

[friskyfrankie]

If any plugs are fouling you need to figure out why - if not replacing them is only a short term fix. Could be a bad or dirty fuel injector (assuming we're not talking about oil fouling). I use ATS CRF 505 to keep the entire system clean. Certainly NOT cheap but is VERY effective.

[Lutrova]

I looked briefly for my post last time I pulled the plugs, but I can't find it. If these cars are known to have valve stem issues - and after 37 years I have no problem believing mine could - that would definitely explain a spark plug misfiring. On the other hand, if one or more of the injectors are bad, wouldn't that be something the cylinder balance test could catch?

[jaywish]

I had a injector stuck open and it did not get picked up on the balance test. I found it when another eased to operate. When I fixed that, with all new injectors, eventually I had to up the temp of a plug one notch as it was not keeping clean like the others. IIRC it was number 8, the passenger side rear cylinder.

I used platinum plugs in conjunction with a slightly hotter coil. All was great after that with one hotter plug and the hotter coil.

[gadget73]

if its got valve seal issues it will go through oil and you'll likely see some smoke on cold start or when pulling away from stops. If its not doing that I wouldn't be too concerned. It is possible to change them in the car and you can also fit the later, better type, but its sort of a miserable job. I did it on mine when the cam swap ate all of them and it started drinking oil like crazy. 14/16 seals were wasted and it went from zero oil use to a quart in 600 miles. Its a lot of time spent bent over the fender working on the engine. None of it technically difficult, its just hard on the back. I did the job easily in a day, not rushing and taking lots of breaks.

second the rattle thought as being endlinks, but bad caliper bushings will do this too, so will loose / missing shock bolts. These things are prone to stripping those lower bolts out.

[87gtVIC]

You can look at wetsanding residue to make certain the panel you work on is clear coated or single stage.

In your case...black residue=single stage

clear/milky=clear coat.


Good luck. That peal is unsightly.

[Lutrova]

Lower shock bolts are both present. That same thought had crossed my mind.

Will loose sway bar links appear worn visually or by pulling on the sway bar? Nothing looks amiss, but if there's only play when the suspension is loose after a bump, that could do it. The end link hardware definitely looks like it's the right size to make a light rattle, and I think both sides were replaced last in 2016.

[DerekTheGreat]

if its got valve seal issues it will go through oil and you'll likely see some smoke on cold start or when pulling away from stops. If its not doing that I wouldn't be too concerned...

Every 302 I've ever owned or maintained has used oil more than any other engine under my care, except for the 305 in the Firebird. Although they usually don't start to consume oil until about 600 miles or four months into the oil change. In the case of that '89, we never saw smoke at any time, just started fouling the plug. Would take about 300 miles or so to foul it up. Sort of surprised my '88 hasn't started to foul plugs. It's got the same ones that were dropped in some seven or eight years and 40k+ miles ago.

Other than the dust shield and that upper ball joint, the stuff in the photo looks OK. Perhaps that link is a little loose, all I check for is play in stuff up & down and side to side. You might try pumping more schmoo into the ball joint and bending that dust shield straight.

[gadget73]

none of my HO engines have ever had oil usage issues and two of them have been well north of 200k mile engines. The original in the Towncar leaked massively, I did fix it but it immediately wiped out a bearing so I don't honestly know if it burned oil. It went through a quart every 200 miles, but less than 100 miles after fixing all that it was knocking and got parked. Thats the one and only non-HO 302 I've ever had and I had it in running condition for maybe 4 months nearly 20 years ago at this point. The HO in the Towncar before I rebuilt it had enough cylinder wear that the pistons would wobble in the bores, and it still never needed oil between changes or fouled plugs.

anyway, endlinks you can usually visually check. If the donuts are all present and just giving it a shake by hand doesn't make the noise, probably not it. usually when they fail its either obviously broken, or one of the donuts turns to dust and the whole stack of stuff is loose.

if the backing plate is cracked or has a missing rivet it can rattle, but most of these have plastic backing plates. If yours is metal it may be aftermarket and not quite installed right.

[DerekTheGreat]

I should've clarified, meant LoPo. I had one H.O. equipped car, it didn't use nearly as much oil as the LoPo stuff, but did have a taste for it.

[Lutrova]

I replaced the plugs and wires last week. I've only driven it a couple times since, and maybe it's made a difference, but I'm still getting a bit of a jerk when letting off the gas. Haven't had time to do any more diagnosing, so I can't really say what direction I'll go next on the miss. I still need to pull the codes. I've also recently acquired an infrared thermometer, so I might be able to use it find out if any cylinders aren't pulling their weight.

On the front end rattle I think I've made some progress. The noise seems to go away when using the brakes. So I assume that points to the brake pads and the clip that holds them in the caliper? Can anything go wrong with them that won't be obvious once I've taken the caliper off?

[DerekTheGreat]

That is probably trans related, does it do it in every gear or just OD? How did plugs 4 and 8 look?

Worth taking a look. While you're there and have it apart, check for play in the rotors by pushing & pulling on them. If the bearings are too loose, you'll get some play. If it hasn't been driven like that forever you can probably get away with snugging up the castle nut a bit.

[Lutrova]

I was originally thinking it was trans related too, and maybe it is, but the guys who rebuilt it were pretty thorough and still the jerk was there before and after the rebuild. It'll do it out of OD. Can't say for sure whether it's present in first, but it's definitely there in third and fourth, which is where I'm doing most of the driving.

Plug 8 had some deposits, the rest were more or less normal with varying degrees of oil on the threads. I took out platinums and replaced with Motorcraft coppers. Number 8 went one notch hotter.

***

Setting wheel bearing preload seems to be a bit of an art. I've always done it with a torque wrench exactly as the service manual lays out since I don't have a good sense for doing it by feel.

One thing I've noticed long before this rattle appeared is a soft scraping sound when spinning the front wheels. For most of their 'orbit' they spin silently, but there's about a 30 degree stretch where it sounds like there's light contact between the pads and rotor. I assume this is because the rotors are warped, but I doubt that's the source of the rattle.

[gadget73]

the rubber bushings in the caliper can also cause rattle problems when they wear. The caliper will slop around on the pin instead of just sliding back and forth. If there are no rubber cups that the pins slide into at all, then thats definitely it. They do sometimes just disintegrate.

the way I've always done bearing preload is to put the wheel on with the cap off. Tighten the nut using just the socket until the wheel has no slop and turn the nut just far enough past that point to get the cotter pin to go through. That should give no play, but no drag either. Give it several spins and make sure it doesn't loosen up after it squishes some grease out from under the rollers too.

[jaywish]

Yes it is kind of cool getting it just right.