kishy's 1991 Grand Marquis

[DerekTheGreat]

Those you have to reset once they pop. These are great for the little critters:
Uhlik Repeater Traps | The #1 Live Repeater Trap For Rodents

[kishy]

Alrighty, with the road trip (http://www.grandmarq.net/vb/forum/si...e-dragon-2024/) being complete and both the car and I having made it home fine, there are some findings over the course of the trip that should be evaluated or at least noted.

First, bringing over the stats as noted in the road trip thread:

States visited or driven through: MI, OH, KY, TN, NC, VA, briefly WV, MD, DE, NJ, PA.
Worst drivers found in: VA once again! They found new ways to be annoying this time, but they were still the worst in really obnoxious ways.
Tolls paid: about 10 USD but one of the booths was bill-by-plate only so a bill may or may not appear in the mail for an amount I will not know until/unless it does
Distance driven: 2403.5 miles or 3868.1 km per trip odometer
Fuel consumed: 125.8 US gallons per actual fuel station pumps
Fuel economy: 18.91 US MPG average across trip per actual calculation of actual fuel vs odometer in each leg of the trip. Low 14.4, high 22.4
Highest elevation reached in the car was 6320 ft at Clingman's Dome parking lot (where we proceeded on foot to 6641 ft at Clingman's Dome itself).
Lowest elevation would be essentially zero in Atlantic City.

Prior to this road trip and the work done in lead-up to it, this car had last seen regular use in 2016, before it handed off daily driver duty to the '84 Town Car. That was a relatively extended period of downtime but none of the car's needs before the trip were particularly severe, so it didn't seem like a big gamble to me.

Observations through the course of the trip:

• Over the 2400 miles, it consumed 1.5 litres of Rotella T6 5W40 synthetic HDEO. Replacement oil was added in 0.5 litre increments at fuel stops where I checked the dipstick, and lost oil was replaced with more of the same T6.
  • When the car was parked in 2016, it was already a known oil burner. I don't have an exact figure on oil loss but this car was always more of a burner than a leaker once I addressed the intake and valve covers forever ago. Maybe a litre per change interval, and regardless of oil choice, always changing at 3000 miles / 4800km.
  • This car was always observed to absolutely drink 5W30 while showing acceptable loss (the 1L/4800KM figure) with 10W30. It was also observed to absolutely drink synthetic while showing acceptable loss with conventional. Accelerated loss with a 5W synthetic oil, especially on a trip with a lot of sustained hill climbing, sustained downhill engine braking, and a lot of wide open throttle was not a surprise and does not concern me.
  • As the car feels pretty good for power, to address oil loss I would probably just pull the heads and do valve-related stuff (guides, seals). It is worth noting that this does have a pretty noisy bottom end at cold startup (suspect piston slap) and prior to the 5W40 oil going in, it did have no oil pressure at idle when good and hot. But the 40 weight stuff is apparently filling the widened tolerances adequately and pressure stays up now. So it's fair to say the bottom end needs love but it's maybe not a concern yet.
• The car continues to exhibit aggressive spark knock in conditions which it did 10 years ago, which I never successfully chased down, and still find myself clueless about. 10 years ago, I found that running premium made it go away, but there are some considerations:
  • The transmission behaviour causes the engine to run at much lower RPM than any of my other Panthers in conditions that are prime candidates for spark knock. E.g. hot engine, low RPM, try to get kickdown out of OD, get knocking until the trans performs the shift. Too much load relative to current RPM in those conditions.
  • But, regardless of the transmission behaviour, with a properly hot engine it will also knock at mid-throttle acceleration in a lower gear at higher RPM. It won't do this consistently, just sometimes, and is highly dependent upon exactly how far into the pedal I am.
• The transmission behaviour outlined earlier in the thread is infuriating, but manual 3-4 operation makes it tolerable.
  • TV is set high, in the sense that there is not much more cable available to use. Current gauge readings unknown.
  • The squeal sound before a shift, most notable in 2, suggests a problem.
  • The 3-4 shift is not an immediate "thunk" like my others, it's more of a 2-stage "ka-chunk" with a little gap in the middle. There is no shift flare or slip on any shifts, however it very very very rarely will not actually engage drive until I bump the gas pedal slightly.
  • Transmission behaviour has not changed over the course of the trip. It remains as it was before the trip, which is the same as it was 10 years ago. There is clearly something broken or leaking somewhere but not enough to prevent it working anyway.
• The brakes were quite smooth at the start of the trip and are now quite grabby, most notably the rears feel like something weird is happening.
  • The car still stops very well, but there is now a "tip over point" where the brakes go from "normal slowing down" to "we're stopping NOW" rather suddenly. This can be mitigated with the pedal but it isn't how it's supposed to be.
  • Also, on the trip, what I initially thought was the smell of burning plastic but later realized was hot brakes did come up a few times, and I do not believe it was from the front brakes. I did look for, and could not locate any melting or burning plastic or rubber which could have been the source of the smell, and my friends immediately thought it was the smell of hot brakes rather than plastic.
  • The $6 brake pads did shed a lot of dust and the HPPs up front are filthy now.
  • I plan to take the drums off and check for axle oil leakage, because that could explain the drums getting a little weird.
• The suspension on this has exactly the feel that I want out of it, which is interesting because I once found this car entirely too firm, particularly after putting the KYB Excel-Gs in it, which it still has today. Maybe as they've aged they've softened a bit. They do seem to be doing some damping but that "sideways axle hop" over certain sudden bumps like railway tracks is creeping back into the picture.
  • The rear sags too easily with too little weight. I believe this has CC817 cargo coils, so maybe a stock replacement single rate spring is the right option.
  • Aesthetically, the front could due with dropping a very tiny bit, but I might change my mind about this after the rear goes a tiny bit higher. Perhaps 1/4 or 1/8 of a coil cut, nothing more. It has Moog 8652 springs up front. This car did at one time have the Speedway 925 springs up front and I hated how it drove more than words can express. Looked great, though.
• The leather seats are a substantial step down from the flocked/velour seats when it comes to cornering on twisty roads. Your clothes kind of interlock with the velour-finish seats whereas you just slide all over on the leather.

Zero regrets about taking this car. It performed well, got better mileage than the wagon did, and was comfortable (except for the seat concern as noted above). I do think the 90+ cars have slightly better driver ergonomics than the older boxes, as well (seat angle and position vs steering wheel vs pedals).





(yes, I'm over the line, but note it's the line where you don't mow down oncoming bikers as a penalty)

[Arquemann]

The suspension on this has exactly the feel that I want out of it, which is interesting because I once found this car entirely too firm, particularly after putting the KYB Excel-Gs in it, which it still has today. Maybe as they've aged they've softened a bit.

Last year I put Excel-Gs in the back of my '85, I certainly found them a bit too harsh. I don't understand how so many jizz over the Gas-A-Justs which are supposedly even firmer. Though the random brand NOS shocks I put in the front are kinda sloppy and definitely could do being firmer.

Nice pictures.

[gadget73]

A tidbit I can offer, I saw a puff of blue-grey oil smoke out of your left tailpipe leaving the diner. Valve seals would be a fair guess for that.
As for the squawk noise, having a gander at the 1991 Mark VII manual's section on AOD symptoms

mushy/early all upshifts pile up / upshifts
fluid level
low TV pressure
low main control pressure
valve body bolts loose/tight
valve body valve throttle control valve sticking
governor valve sticking


there is nothing about noises, but I remember you mentioned it won't hold 2nd
closest its got is soft/early/mushy 2-3, and its all the same stuff except "direct clutch assembly burned/worn"


there is a mention in here about "transmission noisy - valve resonance". Not sure if thats the buzzy noise the AOD does sometimes but it says
fluid level
improper band od clutch application, or oil control system
cooler lines grounding
dirty/sticking valve body
internal leakage or pump cavitation


just based on all that I think I might be looking at the valve body for issues. Seems to be the other common thing. If you happen to have a spare late model valve body around, maybe go through that and make sure its all clean, assembled right, and nothing is sticking and swap the whole thing.

[87gtVIC]

Awesome photos! Looks like a blast.

[DerekTheGreat]

I went through 2.25 quarts of oil to go ~1,800 miles. I'd say your oil consumption isn't bad at all. I managed 24.something mpg as a best during our trip over the weekend. Worst MPG reported was around 21. Hopefully this post makes it. Not sure what to correct to fix why this site displays funny and why I can't post.

Edit: Great pictures, black Mercurys are a rare sight. A poor man's Lincoln.
Interested to find out what is causing the change in brake performance. I have yet to deal with grabby brakes.

[kishy]

I had purchased a new AC accumulator, and it arrived the other day. I set about checking various O-rings for visible faults, found none, swapped the accumulator, and started pulling a vacuum. It came down lower than last time, but I was running out of daylight so I had to give up a little early. I was satisfied with no detectable leakage after 30 minutes so I tossed some refrigerant in. I got pressures to about what I wanted based on my findings on the GoogleNetFaceTube, and validated in doing so that my pressure switch is opening and closing at its specified values.

The system is working - that is, I get refrigerated air inside, the condenser gets hot, the evaporator gets cold, the compressor clutch engages and doesn't cycle at idle, there are no undue noises. I do not believe it's cooling quite right and I suspect I put too much oil in, which would definitely cause inefficient cooling. But it's working well enough to save me from a summer of sweat so I may just roll with it until it demands my attention otherwise. I do believe it's cycling at RPM meaningfully above idle, because I can feel the power being taken away and given back on the highway, but it's not a very rapid cycle, so it's somewhere between very slightly low pressure and just working normally. The refrigerant in the car is neither R12 nor R134A so there is a degree of guesswork to this; as a general rule you need less of it and it'll run the high side pressure lower, so the traditional charts for everything don't quite match up. Mildly tweaking the low pressure switch adjustment screw could stop the cycling but it's just going to get left alone for the moment. I do know the pigtail for the low pressure switch is in need of some love, perhaps replacement, since it only makes contact if it's positioned just right.

Spark knock is worsened (in the sense that it happens in broader circumstances) with AC running (seemingly due to load rather than added heat). On the point about heat though, in stop-n-go/extended idle circumstances, the temperature gauge is higher by about a letter - up from the O in Normal to the R - which is about as I remember it when it still had its R12 charge in 2012.

Spark knock will need to be figured out. The timing on this is set a little on the advanced side - I think I remember 11 and a halfish BTDC. But I am certain that I've hit it right on the nose at 10 in the past and also had it knock. I vaguely remember there being some sort of TSB for retarding timing to cure chronic spark knock, but I also like the power it has. Maybe there are some ECMs that just do timing wrong, I dunno. Not too keen on running premium just to shut it up, which past experience says will work...actually I believe it was content with an 89ish octane midrange, but midrange is generally most of the way to premium in terms of price.

[gadget73]

Rare that I suggest such things but maybe see if a run of Seafoam or equivalent through a vac line does anything. I had problems with my S10 pinging badly and that took care of it. Can probably do the same with water honestly, basically the idea is to de-carbon things and see if its just that causing hot spots.

[kishy]

Rare that I suggest such things but maybe see if a run of Seafoam or equivalent through a vac line does anything. I had problems with my S10 pinging badly and that took care of it. Can probably do the same with water honestly, basically the idea is to de-carbon things and see if its just that causing hot spots.

I'm certainly not going to suggest that the combustion chambers are clean, given the known oil burning, but this was one of the steps I took repeatedly 10 years ago and never got it to improve by doing so.

With that being said, I do still own a large volume of Seafoam, leftover from those previous adventures, so maybe I'll go do some neighbourhood mosquito fogging, assuming the stuff has a good shelf life.

[gadget73]

if it did nothing before, unlikely any magic will happen now. I've only ever had it do something truly useful once but its easy enough to try. Maybe specifically run it through the PCV to distribute it to those cylinders, and if you're feeling ambitious see if pulling some through the evap line does anything different. Maybe slightly different juice distribution.

The other thing besides timing that causes pinging is a lean fuel mix.

[kishy]

But surely lean enough to knock would also be lean enough to set a code?
It did it in the distant past with the likely factory original chubby Ford logo O2s, and it's done it with the Motorcraft replacement O2s it still has now.
It runs smooth, has good power, and doesn't miss, so between that and no codes makes me think it can't be lean.
EGR is working. Thermactor is deleted but that shouldn't be doing anything with this, plus, also wasn't deleted until quite recently.

Today, I had a small list of goals. I didn't hit them all, but I did do some.

Goal 1: Check on the state of the exhaust hangers as there is an occasional gentle banging noise that I can't quite trace.

Findings: The hangers are all intact and working. There is one spot where a tailpipe may be laterally smacking into the frame rail making a dull ringing sound but I don't think that's what's happening.

There is a rivet broken on one of the front brake dust shields. 95+ having steel dust shields, this is an opportunity for a metal noise if it's moving around. Might be it.

Goal 2: Rotate tires due to quite apparent wear from the road trip. Done.
There is a wear pattern suggesting a toe problem up front but it drives so well that I really don't want to mess with it. The cars of mine that have been aligned always end up just a little tiny bit annoying in some way, but this one is as near to perfection as I think it can be. This car was aligned after getting big brakes by a different shop than has done all my other stuff since.

Goal 3: check rear brakes for obvious cause of grabbiness, such as axle oil leakage.
Findings: right side looks normal. Left side does have axle oil leakage, but there is very little of it and it doesn't appear to have made it to the shoes, but it's hard to be sure. I'll formulate a plan for this, because while it's super easy to just throw some seals at this, if the car gets rear discs or 11" drums, there are "might-as-wells" to address while the diff is already drained. Friend has a 2000 parts car heading for scrap soon, and it sounds like he doesn't mind me raiding it for stuff.

Did observe that both drums seem to get good and warm on this one. Not as bad as what I had to deal with on the 84 at one point, but it's clear the drums are doing work.







Goal 4: Address/explore rear ride height by installing new constant-rate springs for a sedan Ford/Mercury
I purchased two sets of Duralast-branded springs from AutoZone (they had a coupon code making them the favourable option). If you play with the catalog on RockAuto or other auto parts stores, you'll find some weirdness around springs especially in the late box years. 91, for example, is said to take the same rear springs as an early 80s Lincoln (and nothing else). While we know all this stuff does fit, obviously springs are set up for different weights in different applications so I very much doubt an early 80s Lincoln, which should weigh more by a meaningful amount, would use the same springs as a 91 Grand Marquis.

Tonight, I took out the Moog CC817 Ford/Mercury sedan cargo coils and put in the Duralast 5557 constant rate springs, which are listed for 79-81, 86-90 Ford/Mercury. Got them in just fine. Car visibly does not seem to sit any different, which almost certainly means after a little while it'll sit too low on them. Moderately annoying.



Goal 5: Check state of fuel return line hackjob. Verify hose is not sliding off, and verify proximity to exhaust is acceptable.
Did not get to this. Not particularly worried about it as I did a quick visual check of this during the road trip.

Goal 6: Install trailer hitch.
This is, above all else, a) because I have one for it and b) to get it to stop taking up space. The car is unlikely to ever tow anything, but a bike rack is obviously very likely at some point.

[gadget73]

At one point in the various combos of stuff I had my car ran lean as verified on a dyno, but never set codes. Just a thought. This being stock I doubt it should be but its not impossible you have one or two weak injectors and its running a little too fat on the others on that bank to compensate. Overall mix is right but some individual cylinders may not be.

If you have a mind to dig through the master parts manual for spring stuff, the base part number is 5560, and there are an absolute laundry list of the things depending on spring code. Not going to post it all but just for 1980 Vic/Grand Marq there are 23 different rear spring codes. It got to be a shorter list over time but there are just a lot of spring codes for these cars, and no specs provided on any of them.

[Tiggie]

It is typical Ford stuff that spring letter codes higher in the alphabet indicate higher spring rates. This would be the single letter codes and not the three letter codes on the springs themselves.

[kishy]

On the whole lean thing - 10 years ago (give or take) I did replace 7 of the 8 injectors. I tried for all 8, but one was defective, so the original remained in that hole. When the warranty replacement arrived, it just sat on the shelf instead of getting installed, and eventually went into the since-sold 86 MGM which had a dead injector.

The spark knock issue existed identically before as it does to this day. The one injector is a wildcard, obviously.

The spring rate nonsense is exactly my type of nerdiness to try to explore, but the master parts manual is an enormous pain in the ass to navigate. Once I upgrade my desktop PC arrangement to have two 4K monitors I'm more likely to want to dig around in there.

As for the car:
The air conditioning is definitely not working correctly. Upon initially turning on, it makes a weird slurp-clunk noise, which almost sounds like I'm hearing it through the evaporator core into the interior (I've theorized it's a big pool of oil at a low spot getting blasted through the system by the compressor kicking on). It is cycling with some regularity when the engine RPM is above idle, however does not cycle at idle. Vent temps have gotten warmer, but it's still enough of a difference from outside air to keep things nicer than outside on a humid sunny day.

Took the car to a car show yesterday. The local Kenny U-Pull has started doing monthly car shows with a nod towards unloved 80s-90s survivors, and thankfully they run these shows at hours that aren't fundamentally incompatible with my life and sleep schedule (11-3, vs the ridiculous and should-be-illegal 8AM Sunday morning nonsense that is commonplace). Obviously, there are only so many appropriate cars, so you get a little bit of everything, and that's cool. This one got a fair bit of attention.

The junkyard did an impressively poor job with photos for their post, but here it is: https://www.facebook.com/KennyUPullW...FuyESXQKo5U6Yl

In the evening, I slapped a coat of paint on a U-Haul/Draw-Tite hitch, since the powder coating has chipped off in a few spots, and depending on my motivation levels tonight I may bolt that on. I've had pretty good luck buying discounted new-old-stock hitches on eBay at good discounts; this and the 83 are the only two remaining without 2" receivers, and I have a hitch on-hand for that car as well.



Also found this while out and about later:



I do believe I've seen this one on the road before, but many years ago now. It has a factory-looking CHMSL so it should be an 86 or 87.

[sly]

yeah... potato tastic pics there at the show.