The Driveway: COBbies talk cars

^^ No, there were little vacuum hoses running to everything that needed vacuum to work, from the little reservoir canisters. And if a vacuum hose develops a leak, whatever it's supposed to operate doesn't work.

Vacuum is used for a multitude of things, even today:

Manifold Absolute Pressure sensors - ECM uses it to determine, in conjunction with the engine's RPM and O2 sensor voltage, how hard the engine is working, so it can determine how much fuel to pulse through the injectors at that moment. Not all cars use MAP sensors; some use Mass Air Flow sensors to directly measure the incoming air mass, which tends to be more accurate - and more delicate - than MAP-based systems.

Your brake booster relies on vacuum suction to boost the apparent pressure delivered to the brake calipers. Press your brakes when the car is off. It gets rather difficult really quickly, doesn't it? No vacuum assist; it's all muscle effort on the hydraulic cylinders doing all the work. Vacuum makes life much easier for you when you want to stop your car.

Vacuum also pulls combustion byproducts out of the engine's crankcase, like fuel vapors blown past the piston rings, and any moisture that condenses in the engine crankcase. Once your oil is up to temperature, any water contamination in the oil is vaporized and then sucked into the intake to be passed through the engine. We call that the PCV, or Positive Crankcase Ventilation. It's an emissions thing, but is essentially a passive system.

Vacuum is used to pull air through your charcoal Evaporative Emissions Canister; this traps evaporated fuel vapors from your fuel tank and fuel system. When the valve opens, the engine's vacuum draws those vapors out of the canister and the vapors are burned, rather than released into the atmosphere. Another passive emissions thing.

Your air-conditioning system commonly relies on vacuum to position the vent doors and ducts to route airflow as demanded, although I bet more cars today use electrical servos to do that now.

As mentioned, all vacuum is generated inside the intake manifold, as when the car is idle, the throttle plate is shut, and the action of the pistons and valve train generates several inches of partial vacuum inside the intake path. A vacuum leak can cause rough idle as unfiltered air leaks into the intake, bypassing the throttle valve. A small leak is usually not a problem (but may toss you a check engine light), but since the brake booster hose is really large, so that leak would make your car run like garbage - been there, done that, got the tee-shirt.

I may be forgetting a few things.

Turbocharged or supercharged cars, since they will end up with pressurized air in the intake manifold, needs check valves so that the vacuum items don't go blowing seals and stuff when the car is generating boost pressure.

The T-bird's headlamp covers were vacuum-operated with a dual-action piston-type vacuum motor. Unfortunately a failure of this system could cause the covers to fail closed and disable the headlamps; thus later concealed-headlamp cars had covers that were held closed by vacuum and would open via springs if the vacuum failed. This causes such cars to have headlamp covers that slowly open over a period of days if the car is not run.

The '67 'Bird also had Ford's infamous auto parking brake release if you put it in gear; another vacuum motor released the parking brake pedal when the shifter was moved out of 'P'. Clearly someone didn't think the safety implications through; a knock of the selector would enable the car to move under power in reverse with no other inputs. Worse, some cars (across Ford's range, not just the 'Bird) had shifter detents made out of a weak plastic that wore out over time or even snapped; sufficient wear, or breakage, would allow the shifter to move on its own through the vibrations of the idling engine.

Quite a few cases of unattended vehicles taking off on their own prompted a recall, but there are no guarantees that a vehicle you buy had the work done. Never leave a late '60s Ford with this design unattended with the engine on in Park.

^ Well, that's just brilliant... Just more reasons not to like vacuum-actuated stuff. Electric or mechanical for me.

My car doesn't have the requirement to hold the brake pedal when shifting out of park, just the pushbutton. Not sure when F-bodies got that added to them. Just an electric solenoid actuated by a brake pedal switch, possibly the same switch that toggles the brake lamps.

My dad's old '79 Chevy truck didn't even have a button to press - just pull on the shifter lever (steering column mounted) and bam, you're in gear. It wasn't difficult to knock the transmission on that truck into gear if you didn't mean to, so you learned to be careful about flailing about the steering wheel when the truck was running.

(also, I could turn the ignition cylinder to off and pull the key out, without the cylinder actually locking in place. Pretty fun prank starting the truck without keys...)

Yeah, those Fords had the column shift too. Really easy to knock.

Though the number of Americans who don't use the parking brake at all rather annoys me.

Anyone remember when cars had phones in them?

I'm pretty sure our Benz C-36 AMG had one, but my father never used it.

edited 17th Oct '11 5:37:58 PM by RocketDude

My dad's M320 has it, but he deactivated the system, as it was an extra monthly charge.

Easy as having a bluetooth earpiece or widget in the car nowadays. Time moves on.

That, and given the whole "Distracted Driving" thing...

Yeah, pre-bluetooh phone systems amuse me, and they were common in basically anything that could be considered "luxury" up until very recently...it took a while for built-in Bluetooth supremacy to catch on. Now it's basically everywhere.

In my mom's '11 Volvo XC70, we use the Bluetooth enthusiastically, but the number keypad also doubles as the way to switch between radio presets! I think this was the case in a lot of cars.

edited 18th Oct '11 8:15:08 AM by frog753

And, apparently, some systems do or will (since I don't know if they have this feature yet) delay phone calls by a couple of seconds for safety reasons.

Ever since I saw an '06 Outlander and Endeavor on my favorite used-car site, I've been thinking about the decline and general saga of Mitsubishi. They were pretty big in the 90's, respected and everything. People were more likely to buy one at that time than a Korean car, I presume.

Then they made some mistakes in the early 2000's, and it all went downhill, and by the time I started thinking about cars as a teenager, I had basically forgotten that this whole company (which I used to know like the whole lineup of when I was a little kid, they were so common back then) even existed. I was awkwardly reminded of their continued existence when we went to South Carolina on vacation last spring, and our rental car which was supposed to be a Mazda6 "or similar" was in fact a Galant.

It was thoroughly mediocre. And ever since, I've been pondering Mitsubishi on and off. It's easy to forget about them because I encounter them so infrequently. (I saw a Galant here at school within the past few days, but that's rare.) But as I may have said before, I like to examine the losers of the car world as much as the winners. I've determined that there's nothing really wrong with Mitsubishi, they just made some bad financial decisions and then have continued to make cars that are merely ok while everyone else (mostly) makes cars that are increasingly better.

I'd buy that '06 Endeavor in an instant if I knew it ran well. Or even the Outlander, if I had to. And at least people still respect the Lancer Evolution. I think. At least, they used at some point in the recent past. And the Eclipse has always been somewhat popular.

edited 19th Oct '11 7:58:14 PM by frog753

Well, I think Mitsubishi has been trying to make a comeback, and I hope that the i-MiEV (an electric car) will help them get back up on thier feet.

I get my Golf back! Fixing it is within my budge to do, so I'm going to do it. New alternator, new timing belt. Then, with my next paycheck, new tires and probably brake-work.

The only thing I'll miss from the truck is Sirius XM. It was quite nice to have radio that actually plays music most of the time.

Yay for Drunkie. What happened to it?

The truck is going back to my dad, who will use it for a company vehicle (he's shopping around for something fuel-efficient to drive on a daily basis).

It's funny, but while I had his truck he was borrowing a Mercedes from a friend. I don't know the year, but it was a V12 "Diplomatic Edition" : Run-flat tires, bulletproof glass, etc. God knows why they had it, but we were joking about how my dad was finally acting like a CEO.

It looks like my truck may be going in for electrical problems.

Electrical problems are Teh Suck.

My Buick Land Yacht Park Avenue has a problem with the brake lamps not working, except the CHMSL. Need to fix that so I can sell it, as it's otherwise a pretty solid car. Very good crash ratings, built like a tank.

To do so, I'll have to pretty much re-wire the brake lamps to ron off of the CHMSL cluster. This involves soldering and running wiring in such a way that it doesn't look like a six-year-old did it.

On my TTA, my driver-side headlamp is noticeably dimmer than the passenger side - even worse if I go hi-beams. Might be a dirty connection or a bad ground. Good thing I have a multimeter...

@drunk: Sounds like a Grosser Mercedes.

I got my car back today, and everything was great...until about three hours after I left the repair place and the goddamn alternator warning light came on AGAIN. I know you aren't supposed to drive a car with a bum alternator, but I have to get to work tomorrow and so does DG.

Grrr. Amusement, I lack it.

DS: New alternator and it's not charging again? What are the symptoms?

Might be the positive battery cable coming off of the alternator. My wife's '96 Grand Prix had that problem; the cable corroded about an inch past the terminal off of the Alternator (the ring connector, not the little one that energizes the windings) so that even after replacing the battery (went dead), the car continued to die out. Found out after I tried replacing the alternator itself.

Got some thick wire, spliced the cable, drove it like that for another two years.

I took my car back to the shop. Apparently the alternator was defective out of the box. They apologized profusely, and are currently sticking a new one in, no charge. I will have my car back in about an hour or so.

I missed a day of work because of this, but other than that the repair is free.

Well, that's about as good as you'll get.

Yeah, but its still irritating. Piece of good news; I thought my brakes were going bad, but it turns out they're still all right. My car is simply handling funny because the tires need to be replaced, which I was already budgeting for.

I've also got a cylinder misfire and a malfunctioning oxygen sensor that need to be fixed. Ah, car ownership.

Almost as much fun as home ownership.

The heater fan on mine now comes on only when it feels like it. I don't know if it's the switch, the wiring, the fan motor itself, something else, or some combination of the four. It's annoying.

Misfires: Spark plugs, wires, possible distributor (if it's primitive enough to have one) or coil pack issue. Rarely, engine control module or ignition control module.

I had a wire touching the intake manifold, so when the car was under enough load, the wire would manage to ground out through the insulation and I'd misfire - could barely get the car above 3000 RPM. New wires that were correctly rounted eliminated that problem, and now I can take it all the way up to the 5200 RPM redline (although I've only exceeded 4000 RPM, like, once).