Table of Contents

Car Mechanics and Maintenance

Whatever my current projects are, not meant to be comprehensive.


Follow a Routine


With all the dust from dirt roads, cleaning the air filter should happen frequently! You may as well check fluids and tire air pressure as well. Make sure the engine and ac cooling fans are working.

It's wise to visually inspect tires at every stop.


Quick Washing Your Car


  1. Rinse car with cordless pressure washer.
  2. (optional) Use a bunch of rags (microfiber towels) in a bucket with rinseless fluid. Avoid scratching paint with soiled rag.

Option for pressure washer dispenser bottle

DIY rinseless wash ingredients:
1 tbsp Baby Shampoo
1/2 cup Distilled Vinegar

Wash and wax

Reddit


Practical Tire Aspect Ratio


Racing Cars Do Not Use Low Profile Tires

Roads are not perfectly smooth racing tracks, and even indy or stock-car racing use sidewalls that are 6“ tall. Sidewall flex is desirable for grip.

Indy 500 Racing Tire:
Indy 500 Racing Tire

Stock Car Racing Tire:
Stock Car Racing Tire

In the 70s sports cars came with 65 or 70 series tires (like the 240Z, 260Z, and 280Z). People on forums say this is because tire development had yet to evolve to make lower profile tires. I think that's bullshit from people's belief that development is always for the better.

Also see: Tires Are Critical to Effective Suspensions


Low Profile Tires are Like Jewelry

The truth is that low profile tires are just bling appreciated by an immature clientele. Low profile tires cause a lot of damage so they are also appreciated by suspension and tire shops.


Wider Tires Are More Comfortable Than Narrow Tires

Some people incorrectly assume wider tires give a rougher ride. That's because they continue to use the same pressure on a wider tire that they were using on a stock width tire. The pressure should be less on the wider tire to have the same tire deformation expected by the manufacturers.

Tire Pressure Calculator from tiresize.com

A more comfortable ride can be had by increasing the total volume of a tire.

Increasing the width and keeping the tire height constant, decreases the pressure needed to run the tire. For speed bumps the 2 dimensional vertical deformation is the same for both the wider and narrower tires. At least on speed bumps. On irregular surfaces the wider tire with more volume will be more comfortable.

To be more precise, the narrower tire does have a contact patch that is longitudinally longer, so it may “caterpillar track” over a bump. But the increased volume afforded by the wider tire overshadows what may be a marginal dynamic deformation improvement? I think so.


Tire Repair


Travel Without A Spare Tire

AWD Subaru differentials need same size wheels to avoid damage and I'm not sure how long they could be driven on a different size spare. After a long search I found a spare to match the diameter of my wheels.

Preventative tire sealants would help in surviving without a spare. Also a tire repair kit with tire plugs and vulcanizing cement and patches. But it's a pain to be doing repairs on the side of the road without a full set of tools. So I prefer to have a spare tire.


Liquid Tire Sealant

I watched Project Farm's review of tire sealants and Slime seemed the least nasty looking when he pulled off the tires (although it starts to dry with time). Plus it's inexpensive. Multi Seal FlatOut is more robust but you need more and it's more expensive.

Other Sealant and Balancers

For a regular hole on the tread of the tire, I'd much rather use a plug than use sealant after the fact.

However, wouldn't it be beneficial to have sealant in the tire as a preventative for future flats? Off-road, by the time you realize you have a flat the rim and tire can be damaged as they roll flat over sharp rocks. Off-road versions of Slime can do this for 2 years. Multi Seal for the life of the tire. So Multi Seal may be the better option as my tires will probably last 5+ years.

My 2008 Subaru is not U.S. spec, so by the owners manual there's no TPMS.

Based on sources from Slime and LiquiTube, I should use about half of the recommended amount of a sealant to avoid imbalance. I will be trying my luck with a 16/22 dose of FlatOut Sportsman volume recommended for over-road tires, so I use up 2 bottles on four wheels.

The following from the MultiSeal FAQ seems to have been written before the introduction of FlatOut brand, which has different varieties that seem purely for marketing reasons:

Is MultiSeal a One Size Fits All Solution?

My impression is that those sealants that would plug larger holes work with thicker slow speed tires such as army vehicles, are more viscous than passenger vehicle sealants. Probably different sized sealing particles as well. “Armor 3500 seals puncture up to 1 ¼” in tires that are 18 plies or greater”.

There seems to be a natural limit for any liquid based option of (hole width / hole depth), but added viscosity helps. Except added viscosity hinders tire balance. Which by my guess are factors for having different formulas: Sportsman → HD 2500 → Armor 3500.

Slime as an Option

Slime Reviews

Multi Seal as an Option

Multi Seal Reviews

LiquiTube as an Option

LiquiTube Reviews


Tire Plugs

Tires can be repaired with plugs. “Unlike the vulcanization of a patch to a tire, tire plugs rely on the general pressure of the tire hole pushing on the plug to create a compression seal, rather than a chemical seal.” slime.com. Along with the tire pressure, plugs usually come with rubber cement as an adhesive and a lubricant for insertion.

Most any correctly installed plug will work reliably, as tested by Project Farm.

Aside from regular plugs, they make plugs that are self vulcanizing, such as 1 and 2, and some come with separate vulcanizing fluid.


Sidewall Repair

Sidewall repair is difficult, but can be accomplished by vulcanizing rubber and mesh fiber into the sidewall, using both heat and pressure with a tire press machine. See How I do a vulcanized tire sidewall repair, by Misfit Toys on YouTube Amazing skill of Repairing a Hard Impact Sidewall Truck Tire, YouTube

One company even claims the ability to repair sidewall damage without the need for a tire press machine, by using plugs and separate vulcanizing fluid. See Fix Punctures and Sidewall Gashes with Tech's Permacure Repairs, YouTube. Another company: How To Fix Sidewall Punctures Without Replacing Your Tire, GlueTread on YouTube. Although I wouldn't have faith in that kind repair for long term use: I'd want the patch on the inside.

A good compromise for sidewall repair could be a reinforced internal patch, such as sidewall from an old tire. Sanded and buffed to remove the shiny surface, then glued on with vulcanizing fluid and allowed to set under pressure from clamps.

The clamps can be applied onto additional layers of sidewall placed over the patch to distribute pressure more evenly. No need for using pieces of plugs or other strips onto the tire exterior for a simple tear. Cold vulcanizing fluid doesn't need heat as it is a chemical process.

Here's a good example of what I'm talking about, although he places the patch on the outside: sixtyfiveford on YouTube. Good advice about running the chords perpendicular to the tear. If I adopt his sewing technique, then an external patch would be necessary to protect the threads?


Tire Removal and Mounting

Make sure to mark the position of the tire with the rim.

Any vegetable oil works as a lubricant for mounting/dismounting. Petroleum based oils harm the rubber. Soapy water is corrosive. See The Tinkering Old-Timer on YouTube.

Something else you may have on hand that works well is silicone oil/lubricant or silicone protectant, although the idea is that the lubricant only lubricates temporarily so the tire doesn't slide on the rim when in use.

You can use a low profile car jack to debead the tire. I use a concrete park bench: slide the wheel under the bench but over the jack. May help to place a tire iron between rim and tire before lowering the jack so the tire doesn't return to place.

You can also loosen the bead of the tire from the rim by driving a car over a wooden plank, as shown by Smitten in the Mitten on YouTube.

Finish removing the tire with pry bars. Don't forget the lube. The tire must unseat completely on one side so that the levers can pull the tire over the rim on the other side.

Mounting a car tire on a rim with NO TOOLS in seconds by Spanky’s Hot Rods on YouTube.

In case it's too hard with tire levers/irons or pry bars


Tire Balancing

Searching “reddit bubble balancer”, I find Reddit is convinced that tires should be balanced dynamically for best results, except for thin tires or bias ply tires.

But I'm well aware the hive mind can be erroneous.

Just an FYI, We used quality bubble balancers to balance very high end race car wheels+tires. Cars that exceeded 230 MPH on some tracks. Done correctly, a bubble balancer will give a good result.

the computerized wheel/tire balancers are not always 100% accurate. I've had balance jobs that were never right. That's why road force balancing came into play.

Remember, many computerized balance techs don't put weights on the outside of an expensive rim. They stick 'em on the inside, often dead center. That is in no way, a proper dynamic balance. AND it often works just fine. Cujet on bobistheoilguy.com


Static - Bubble Balancer

Y Method for Static Balancing by sixtyfiveford on YouTube. Also describes the difficulty in finding a quality bubble balancer.

Upgrade for Bubble Balancer by Mad Ginger Customs on YouTube. This guy likes to talk.

More Expensive Upgrade for Bubble Balancer by John Salt on YouTube. Perhaps add a more precise bubble level? See image. Although there isn't room for a larger one.

My Bad Idea

Alternate


Static - Motorcycle

Marc Parnes saying motorcycle static balancers are superior

Will a bubble balancer work for a motorcycle wheel? Reddit

Static Tire Balancing by Robert Deptula on YouTube. He has a bubble balancer but prefers the motorcycle wheel balancer method (see end of video). But did he do upgrades to the bubble balancer? Based on the stiction movement I think I see, he didn't.


Dynamic

Dynamic Tire Balancing by TarzanRiding on TikTok. Does not work. See mental exercise below.

Mental Exercise for Dynamic Balancing

Referring to pre-70's: “Tires were also spin balanced on the car both balancing the tire, wheel and drums of rotors. We also spun heavy duty truck tires on the chassis.” edp9743 on YouTube.

“Useless if the tires are out of round you cannot tell that with a bubble.” danielleclare2938 on YouTube.

Alternate


Shop Balancer Instructions

Know how so you can correct the guy at the shop. Especially if you ask them to double check and the tire doesn't show as balanced: ask right after they balance one, to remount the balance tire and check for balance.

Full Documentation by derekweaver.com.

Mounting Instructions by Hunter Learning Channel on YouTube.

How to Use a Shop Dynamic Wheel Balancer by Brunton on YouTube.

Alternate


Rim Balancer


Maybe the best way is to remove or apply weight using the same strategy as in tire balancing above. Weight removal could be by sanding / machining. But this may affect road force balance?

Idea fail


Wheel Alignment


Wheel Alignment by That Shop Teacher Guy on YouTube.
Camber by Subearu on YouTube.
Toe-in by Embark With Mark on YouTube.
Toe With a Laser Level by Scott Gress on nasaspeed.com

Alternate

Easy visual toe alignment check

To do an alignment on a vehicle with independent suspension, the weight of the car needs to be on the wheels.

So the wheels are free to slide, turn plates are nice because you don't have to roll the car back and forth to settle the suspension.

DIY turn plates: 2 squares of slick, texture free vinyl floor tiles, without sticky-back, with salt applied between them. I've been told oil and grease are too messy.

Settling of the suspension without tools is done by push-rolling the car forward. Does push-rolling the car forward create a drag force unlike when the wheels sit on turn plates?

If your floor is not level, you can also stack vinyl flooring to even out the height differences under the wheels.

Camber and toe require the steering wheel be centered. “If you don’t have a steering wheel lock, you can move the seat all the way forward and jam a helmet between the steering wheel and the seat.” Wayne Scraba

If you don't have the expensive LongAcre caster and camber tool That Shop Teacher Guy has, the formula for caster can be had from Subearu's camber tool measurements:

Expand formula

I don't have easy access to my wheel spindles. I want to have a set of inexpensive wheel clamps to make things easier. One magnet on the disc brake may be a little off, but two is good enough to make a reliable base for the laser toe-in tool and bubble camber tool.

Magnetic Alignment Face
911Fiddler on nam3forum.com

More images

If you don't have a pit from which to make your adjustments like at the alignment shop, you are shit out of luck and have to raise the car to adjust camber as Subearu did. Unless your vehicle has naturally curly hair, er, I mean has “good ground clearance”.


Charging the Battery


A lead-acid battery, measured without load, should not go under 11.9v. It only takes a dozen or so cycles under this voltage to ruin a battery.

“Batteries can be very long lived if they are charged at a float voltage of 2.20 to 2.30 volts/cell (at 25 degrees C) (13.2V to 13.8V for a 12 V battery).” digikey.com

For 2000s model cars, it's likely ok to charge the battery while still connected to the car, but newer cars may have more complicated electronics? Connect the positive terminal first, then the negative terminal.

Can You Start a Car with a Battery Charger Connected?

Starting your car when the battery is charged and the battery charger is connected as well isn’t that much of an issue, and you can start the car easily.

Starting a car on a dead battery with a charger connected can cause the fuse on the battery charger to blow out or burn the charger itself.

Will just starting a car and leaving it on charge the car's battery, or does the car have to actually be driven? reddit.com

You can restore a battery with a welding machine Project Farm


Oil Change


Is it ok if oil is overfill by this much? Reddit. A little is ok, but how much is too much? The dipstick was at the low mark so I added a quart. Now it's quite above the high mark.

Note: accidental overfilling oil into your engine can cause problems too. As the crankshaft rotates it will churn the oil, causing aeration and eventually sustained foam may form. This can lead to overheated motor oil, oxidation and a loss of oil pressure. Spongy aerated oil is hard to pump. It starves the engine and critical lubricated surfaces. Jim Fitch at machinerylubrication.com

My car calls for 5W-30 for cold climates and best gas mileage. However, the owners manual further states: “Recommended grade and viscosity under severe driving conditions. If the vehicle is used in desert areas, in areas with very high temperatures, or is used for heavy-duty applications, use of oil with the following grade and viscosities is recommended.
API classification SM (or SL):
SAE viscosity No.: 30, 40, 10W-50, 20W-40, 20W-50”

Given my engine has 100K miles, I'll be using 20W-50. I'll be waiting a minute after starting the car so the engine warms up before applying load.


Brake Fluid


Using a squirt bottle to pump brake fluid by GerrysDiy on YouTube.


ELM327 / ODB2 Scanner


If you have a Bluetooth ELM327, and have connectivity issues, one last thing to try is to download different software. That worked for me. For some reason the software made for my ELM327 doesn't connect.

After reading numerous sites and forums, I think it's fine to clear an error code after logging it for future reference. Sometimes there's a glitch and the error doesn't return. For example, random codes can pop-up from having disconnected the battery.

After clearing a code, if the problem persists the error may not return immediately. Some issues require driving a sufficient number of miles (50-70) for the computer to re-diagnose the issue.

For emissions related issues, after clearing the code(s) you will have to wait through a “drive cycle” before the engine light comes on. That can take several weeks, although you can look in your car's owners manual for more specifics.

This Car Scanner app shows which emission tests haven't passed, though it doesn't distinguish between “hasn't passed yet” or “failed”. The engine light will let you know of a fail.


Exhaust Manifold Coatings, Wraps, and Heat Shields


Some super thin ceramic coatings may change surface emissivity but won't much change the surface temperature of the exhaust. I kept seeing really convincing pieces such as this popularhotrodding video. I'm amazed by how deep the marketing rabbit hole goes.

An rx7club.com forum helped guide me away from false marketing.


Exhaust Leaks


Easiest Way to Find Exhaust Leaks, Shiny Fast & Loud on YouTube


Grease for Electrical Connections


Dielectric Grease is what you will use for automotive applications: Moto Mythbusters Dielectric VS Conductive Connector Grease, Taco Moto on YouTube.


Engine Sound: Piston Slap or Worn Valve Clearances


My engine has a more faint version of the clanking sound in the YouTube video referenced in this forum thread. Also could be a need for valve clearance adjustment, as can be heard in this video. The sound lasts a few minutes on cold startup, and goes away more quickly if I rev the engine.


Engine Overhaul or Rebuild


Performance Engine Rebuild by Project Farm

Total Overhaul at 100K by Project Farm:

“Let's go through a vehicle that has over 300,000 miles on it from top to bottom and front to back to prepare this vehicle for another 100,000 reliable miles! Includes rust repair, front end rebuild, complete tune up, axle hub bearing replacement, fluid changes, new brakes and rotors, front end alignment, headlight bulb replacement, MAF sensor cleaning, tensioner pulley bearing replacement, fan clutch replacement, axle seal replacement, and A/C freon level check.”