The "Ask a Mechanic" Thread (merged)

[SpringfieldSkins]

can you fix the air conditioner unit in my bedroom?

Did you try opening up the vents? If that doesn't work, window units are certanly a viable option.

[zoony]

Should I be worried about dropping my wife's car off at the dealer.. or having her take it down... for radiator and transmission service...

and they don't do anything? How would I know if they changed the trans fluid? (Honda you can only do 2 quarts at a time) How do I know if they've flushed/replaced coolant?

[SpringfieldSkins]

At what mileage should the timing belt of a 98 Infiniti I30 be changed?

I'd have to consult my trusty service guide, which is on my computer at work. If I remember correctly though, the I30 has a Nissan 3.0L engine which is driven by a timing chain. If so, timing chains do not need to be replaced.


If I remember, I'll try and look it up for you tomorrow and get back to you.

[Redskins Diehard]

I'd have to consult my trusty service guide, which is on my computer at work. If I remember correctly though, the I30 has a Nissan 3.0L engine which is driven by a timing chain. If so, timing chains do not need to be replaced.


If I remember, I'll try and look it up for you tomorrow and get back to you.

That is what I wanted to hear. Good idea for the thread and thanks for the info.

So you are an advocate for the full transmission flush and not just a drain and add?(I know you can't get it all out, but I think most of it)

[PokerPacker]

uh oh, looks like the "ask a ____" threads are making a come back

[SpringfieldSkins]

Is it common practice at dealerships for service advisors to target cars coming in for state inspections for " unneccessary repairs" that are needed to pass inspection? I guess what I'm trying to say is do dealerships ever say, "You need that front strut replaced or it won't pass inspection". Joe Blow then panics because he doesn't want a rejection sticker and says.."Ok, go ahead and fix it". When the front struts are in fact perfectly fine and don't need to be replaced. It would seem to me that state inspections are the perfect time for dealerships to increase profits.

While I won't deny that the inspection station we have at my shop does increase the profits to the station, our inspector will never fail anything that shouldn't fail. People will usually choose to have something fixed while we have it at our shop because it's more convenient for them. All the work we do is because something has actually failed and the work is 100% done. I can't speak for other shops, but it certainly wouldn't surprise me to see shady shops do something like that.


Also, if I'm selling a ticket that and there is something that will fail, I will certainly let the customer know about it. One reason being, I don't want the customer to be pissed at me because I didn't tell them their car was going to fail inspection.


If we find something that will fail inspection, but say the inspection isn't due for 3 more months, I'll also inform the customer of that and give them the option to fix it now or later (if it's not something dangerous). Things like lenses can fail inspection here in VA eventhough it doesn not pose a risk to the person driving the car. I try to give the customer all options available while being as realistic as possible.

[skinfan2k]

I have recently been putting fully syntheic oil for my oil changes. Is it really worth it putting that over regular oil

[zoony]

uh oh, looks like the "ask a ____" threads are making a come back

this is a great thread imo. Hopefully ss will be around for a while so we can randomly bump this when we have questions.

Next thread we need is "ask a lawyer"

(I always said I wished I had two brothers .... one who was a mechanic and the other a lawyer. 2 professions all of us need, but you can never trust )

[HogNose]

this is a great thread imo. Hopefully ss will be around for a while so we can randomly bump this when we have questions.

Next thread we need is "ask a lawyer"

Has there ever been an "Ask the Doctor" thread?

[zoony]

Has there ever been an "Ask the Doctor" thread?

I dunno, that'd be good too. Doctors tend to be too busy to post here though

Blade is a doctor, case in point

[SpringfieldSkins]

Should I be worried about dropping my wife's car off at the dealer.. or having her take it down... for radiator and transmission service...

and they don't do anything? How would I know if they changed the trans fluid? (Honda you can only do 2 quarts at a time) How do I know if they've flushed/replaced coolant?

I don't think you should be worried. I don't view women any differently than I view men who come into the shop, both can be equally as ignorant when it comes to cars.

If you have suspiscion that they might be shady, or you just plain don't trust them you could try this. With the transmissin fluid, take a sample of the fluid, use something white that won't absorb the fluid (like a nice piece from the China cabnet). Get dip the stick and get a few dabs of ATF on the dish, enough to clearly make out the color. Take a picture, make sure it's nice an bright so you can make out the color in the picture. When they are done, repeat this process and see what color difference there is. In the end it should be nice and pink. If it's pink before, it doesn't really need to be flushed in the first place. As far as the coolant, you don't really have much to go on as far as sampling like that, unless the coolant is really nasty.

Some Hondas don't have transmission cooler lines, which are used to peform the flush. They do have to drain and refill the transmission because there is no other way to do it. If you Honda has cooler lines, it should be flushable. If they can't flush it, it may not look "perfect" afterwords, but it should be noticably better.

[SpringfieldSkins]

That is what I wanted to hear. Good idea for the thread and thanks for the info.

So you are an advocate for the full transmission flush and not just a drain and add?(I know you can't get it all out, but I think most of it)

I much perfer a flush over a drain and fill. Reason being, the flush gets 100% of the fluid out, and with a great cleaner pre-flush much of the dirt as well. My main issue with a drain and fill is that it doesn't remove all of the transmission fluid.

Transmission fluid is a detergent, meaning one of it's purposes is to clean. Anyone remember the old "fix" of adding a drop of ATF into the combustion chamber when changing spark plugs to clean the combustion chamber and help seal the piston rings? ATF being a detergent is the reason that one worked.

When you don't replace 100% of the ATF, you have a couple of quarts of old fluid beaing cleaned with the new fluid. If that fluid was pretty dark to begin with, the fluid will be back to the same within several thousand miles.

The only case I would even think of recommending a drain and fill over a flush would be if a vehicle had transmission problems and the fluid was black. Likely that car will need a transmission anyhow, but that would be the least entrusive route to take given the circumstances.

[DCsportsfan53]

2 questions... is the fuel injector service bs? especially if you've been using Techron every 5k or so?

Also, talk to me about changing coolant. Honda manual says 100k... Honda dealer told me 50k. Dealer claims manual is BS, written to satisfy the EPA. WTF. (they also said the same about transmission fluid intervals, etc.)

also, tell me about radiator flushes

The fuel injection service is not bs but it is oversold. It's good to do once in awhile, though, as it does do a pretty good job busting up all that carbon that builds up over time. I would say, though, that the need for it is going to be heavily based on driving conditions. If you do a lot of stop and go, yeah it's going to be helpful to do that every, say, 30k miles. If, however, you are frequently running the engine at full operating temperatures for extended periods of time and letting it stretch its legs a little bit, you probably don't need it.

As far as coolant, I don't go by mileage, I go based on the condition of the coolant and how dirty the coolant/cooling system is. In general, radiator flushes done with the stupid machine are pretty worthless. Personally, I don't bother selling them or the stupid power steering flush because I think they're just ways to get money out of your pocket into mine. That doesn't fly with me. If I'm working on a car and I think it's time the coolant's going to be changed, I'm going to do a full on flush of the whole system, not just change a quarter or a third of it with the machine for a quick buck. I like to run the car, with the return line disconnected and a hose in the coolant bottle, for a good half hour. That really gets all that crap out of there.

Also, just as a note, be very careful about mixing coolants. I've seen engines nearly ruined because people mixed coolant types. When you do that, the newer style long life coolants break down into a brown sludge that just clogs up EVERYTHING. Many times you will never get it all out of the cooling system.

Why do you try to sell extra services?

He's right, to make more money. Personally, I probably cost myself just a little bit by avoiding the services I feel unnecessary even though they're technically "recommended" (by the company selling the product to us, anyways). I'm a HUGE stickler for not trying to sell anything to a customer that the car doesn't actually need or isn't truly preventative maintenance. I stay away from all those BG and MOC flushes and crap. About the only flush I routinely sell is a brake fluid flush because brake fluid absolutely should be changed every two years regardless of mileage.

At the same time, though, it's not like if I'm doing an oil change on a car and I notice things wrong with it that I'm not going to try and sell that work. It varies greatly from shop to shop and tech to tech on what their standards are.

[SpringfieldSkins]

I have recently been putting fully syntheic oil for my oil changes. Is it really worth it putting that over regular oil

This really a loaded question, so I'll try and explain.

First of all, I'll let everyone know, I just bought a new car. I plan on changing the oil at approx. 1,000-2,000 miles to Mobil 1. I plan on continuing my use of Mobil 1 for the life of the vehicle. To me it's worth it.


Now, I'll try and explain oil.

Oil, as we all know, is a petrolium product. All petrolium products contain sulfur among many other things. All oils contain additive packages such as friction modifiers to help prevent the oil from breaking down and causing a loss of viscosity or lubrication. Conventional oil (non-synthetic and non-semi-synthetic) contains sulfur which, when combined with heat and moisture will create sulfuric acid. Sulfuric acid eats through the additive packages, breaks down the oil and causes engine damage eventually. Synthetic oil (Mobil 1 among others) is not something that is synthesized in a lab, contrairy to popular belief. Synthetic oil is petrolium, just like the rest, but has all of the sulfur synthesized out of it. Without the sulfur in the oil, sulfuric acid will not build up as quick (read further) and will last a lot longer without breaking down. I say will not build up "as quick" because sulfur is still introduced into the oiling system from combustion.

All of this means, your engine will be better protected for a longer period of time with a full synthetic oil. Conventional oil still protects, but breaks down much sooner than a synthetic.


My opinion: If your car is new, or fairly new, it would be worthwile to use a synthetic oil. If you have the money, why not afford the extra protection for the most important piece of the vehicle. Not saying, don't use conventional oil, just make sure you don't go 10K miles on conventional oil and expect everything to turn out rosy.

[SpringfieldSkins]

When you do that, the newer style long life coolants break down into a brown sludge that just clogs up EVERYTHING. Many times you will never get it all out of the cooling system.

You mean they don't make brown coolant?