I work on cars. AMA

[Anonymous]

I always used to turn off the AC before shutting off the engine so that the AC would not be on when I came back and started it up again.

But, with the new screens to control the AC (not just a button or dial), I never shut the AC off before turning off the car anymore.

Is it bad to start the car with the AC running?

[Anonymous]

Anonymous wrote:There is water leaking into my car. It pools on the drivers side floor. I’ve checked the sunroof drains. They seem clear. Per google, I lifted the hood and cleaned debris under the hood at the windshield-that helped but did not solve the problem. Do you have any ideas? My car is so stinky. It’s a 2012 Highlander.

I had that happen. A body shop suggested I tear out the door panels--$$$. After a number of false leads, my mechanic cleaned out the drain from the A/C. That fixed it, and it didn't cost much

[Anonymous]

This might be the most helpful thread to the most people on DCUM ever. Thank you!

[Anonymous]

If I have a car with synthetic oil, normally good for 7-10k miles, and if I end up driving, say 2k miles per year, can I wait 3-5 years before the next oil change at 7-10k mark or do I need to change it more frequently? Does oil degrade with time even if not used/in circulation in engine?

[Anonymous]

I know in MoCo, they have an auction every few months of seized vehicles. Ever been to one of those? Worth it?

[Anonymous]

Most of my driving during the week is to take the kids to and from school. It's 10 minutes there. 10 minutes off while I take them in side, then 10 minutes back. Twice a day. Based on your previous post, this isn't great for the car as it's not running long enough. Any suggestions, other than driving circles around my block and annoying my neighbors? We do get longer drives done on the weekends. It's an Audi 2.0 4-cylinder TFSI (turbo) engine if that makes a diffrence.

[Anonymous]

Anonymous wrote:

Anonymous wrote:What's the best way to buy a vehicle in good condition from the 80s?

From the 80’s? Probably at a classic car auction or a for sale ad on Hemming’s Motor News.

Pretty much the only cars still left from the 80’s are the “keepers”, that the owners specifically wanted to hold on to. That means they’ve been maintained, but also means they’ve lasted long enough that their value is starting to creep back up. Fox Body Mustangs, for example. You couldn’t give away a 1987 5.0 in the mid-2000’s. But now? One in decent shape will run more than it cost new in ‘87.

Thanks! I was looking for a 300-something Mercedes, maybe a wagon, unless you think that's a terrible idea. But I'll check out the mustang you mentioned.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:I used to do it for a living, then I didn’t, then I did again, then I bought a shop, then I sold a shop, and I still work on my own cars and trucks as a hobby now.

So ask me anything. I’ll answer it if can.

how do you change the tires on a 1963 Dodge Dart?

in the 450sl how did they balance weight in rear of car?

What is purpose of STP and who developed it?

How many times it took to created WD40?

16.5” bias ply tubed tires? Or 16” with tubeless radials? Specifiy please.

The battery is in the trunk, IIRC. Why anyone is worried about F/R weight distribution in a soft-sprung convertible tourer driven by tennis wives is beyond me though.

STP was invented by Wayne LePard, the father of the kid down the block from me when I was growing up. I know this because he had an STP sticker on his 1965 Falcon hotrod. It was badass.

40 I suppose. Dunno, I dont use it much, since I’m not an electrician. Being that it’s mostly kerosene, it dissolves grease and oils that are currently in place, so it’s not a very good lubricant. Yeah, it makes the squeaking stop temporarily, but when it evaporates, there’s even less lubricant than before. I use it for cleaningg out water from wiring harnesses in flooded cars, but that about it.

[Anonymous]

Anonymous wrote:I always used to turn off the AC before shutting off the engine so that the AC would not be on when I came back and started it up again.

But, with the new screens to control the AC (not just a button or dial), I never shut the AC off before turning off the car anymore.

Is it bad to start the car with the AC running?

Great question...

[Anonymous]

how do you change the tires on a 1963 Dodge Dart?

in the 450sl how did they balance weight in rear of car?

What is purpose of STP and who developed it?

How many times it took to created WD40?

16.5” bias ply tubed tires? Or 16” with tubeless radials? Specifiy please.

The battery is in the trunk, IIRC. Why anyone is worried about F/R weight distribution in a soft-sprung convertible tourer driven by tennis wives is beyond me though.

STP was invented by Wayne LePard, the father of the kid down the block from me when I was growing up. I know this because he had an STP sticker on his 1965 Falcon hotrod. It was badass.

40 I suppose. Dunno, I dont use it much, since I’m not an electrician. Being that it’s mostly kerosene, it dissolves grease and oils that are currently in place, so it’s not a very good lubricant. Yeah, it makes the squeaking stop temporarily, but when it evaporates, there’s even less lubricant than before. I use it for cleaningg out water from wiring harnesses in flooded cars, but that about it.

The Dodge Dart had 13 inch rims. You remove lug nuts counter clockwise one side and clockwise other side. The 450sl in trunk opposite of battery has a hidden piece of concrete hidden to counterbalance weight of battery on opposite side of trunk

STP is Studerbacker Packard

WD - Water displacement was invented on 40th try

[Anonymous]

Anonymous wrote:I always used to turn off the AC before shutting off the engine so that the AC would not be on when I came back and started it up again.

But, with the new screens to control the AC (not just a button or dial), I never shut the AC off before turning off the car anymore.

Is it bad to start the car with the AC running?

It puts some extra stress on the starter and serpentine belt, but probably doesn’t do any real harm.

[Anonymous]

Anonymous wrote:I always used to turn off the AC before shutting off the engine so that the AC would not be on when I came back and started it up again.

But, with the new screens to control the AC (not just a button or dial), I never shut the AC off before turning off the car anymore.

Is it bad to start the car with the AC running?

Not OP. Should not be an issue, but requires just a little extra juice from the battery when you start the car, won't affect you 99% of the time, but if battery is weak for some reason (battery is old or have not started the car in a while, or if its very very cold outside), starting the car may be an issue.

[Anonymous]

Anonymous wrote:If I have a car with synthetic oil, normally good for 7-10k miles, and if I end up driving, say 2k miles per year, can I wait 3-5 years before the next oil change at 7-10k mark or do I need to change it more frequently? Does oil degrade with time even if not used/in circulation in engine?

It doesn’t degrade, but you should change it at least annually. Reason being, oil accumulates gasoline contaminants and combustion products from the cylinder walls. If the oil heats up enough during driving, these contaminants are partially boiled off. But cars that don’t get driven enough to boil them off hold them in solution with the oil, and they can damage seals and other parts. Changing the oil is the easiest way to get rid of them if you don’t drive enough.

[Anonymous]

Anonymous wrote:I know in MoCo, they have an auction every few months of seized vehicles. Ever been to one of those? Worth it?

No, I haven’t. I don’t like asset forfeiture laws, and I won’t be part of supporting that system by patronizing it.

[Anonymous]

Anonymous wrote:Most of my driving during the week is to take the kids to and from school. It's 10 minutes there. 10 minutes off while I take them in side, then 10 minutes back. Twice a day. Based on your previous post, this isn't great for the car as it's not running long enough. Any suggestions, other than driving circles around my block and annoying my neighbors? We do get longer drives done on the weekends. It's an Audi 2.0 4-cylinder TFSI (turbo) engine if that makes a diffrence.

So in that sort of driving profile, a few things are happening. None are good.

1) your exhaust system is accumulating water inside it, and staying moist, which will eventually corrode it. Yours is made of stainless steel, but the muffler internals and catylist housing is mild steel. That will eventually rust. When gasoline is burned, the biggest by product of that combustion is water vapor. Ideally, the exhaust system will get hot enough during a drive to ensure that all that water stays in a gaseous state all the way out the exhaust system. But before it gets that hot, the rear parts of the system are still cool, and the water vapor condenses there. Unless you get the exhaust hot enough to boil off that water, it’ll have moisture in it.

2) the battery isn’t being charged enough by so litttle driving. You’re in a constantly descending charge state that will eventually not be able to start the car. Think of it like this- this is just a hypothetical, but accurate- let’s say it takes 10:30 of running to replace the electrical charge used to start the car. But you only drive 10:00. So each time, the battery gets :30 too little charge. Over time, that cumulative effect will slowly drain the battery

3) your engine oil isn’t getting hot enough to boil off the contaminants from the gasoline being burned. Same deal as the water in the exhaust, except it’s petroleum contaminants instead of water. Hot oil boils them off and sends it into the PCV system to be burned and disposed off in the exhaust.



Pick one day a week and drive for thirty minutes to an hour, ideally at highway speeds. Also, really get on the throttle aggressively and run it very hard a few times on these weekly drives. Plus, your car is a lot of fun. Go enjoy the performance.