The "Ask a Mechanic" Thread (merged)

[SpringfieldSkins]

QUESTION:

94 Subaru Impreza, manual transmission. When I turn the fan on, it makes sort of a chugging wheezing sound like someone having trouble breathing. Not very loud, but noticeable and you can feel the engine struggle just a bit every time it "exhales." This is only when its idling. Once placed in gear and moving, it subsides until it goes away completely at highway speeds. If I idle long enough, it sometimes stalls. Does it with AC, heat, or just the fan. No symptoms of engine trouble at all when the fan is off. No check lights on. Started doing it right after my last oil change.

I'm assuming that you are talking about the fan in the car, the blower that blows head and AC on you. It kind of sounds like the fan may be locking up and drawing on the battery causing the engine to stumble because the battery power is not constant.

I doubt it has anything to do with your last oil change. I would recommed you take it into a shop because I don't really have an answer for you insofar as a common problem I see. I could be completely wrong about my thoughts, but if it's stalling, you should probably address that.

Pre 1996 (Pre OBD 2 or On Board Diagnostics 2) vehicles are very finicky with their check engine lights. They are not the most reliable when it comes to thinking you have a "real" problem with the car. Just a side note.

[SpringfieldSkins]

how can you keep a car in good repair driving on super dusty to muddy dirt roads all the time?

The undercarraige looks pretty caked and there is insidious moon dust everywhere.....

It's very hard I'm sure. A pressure washer and some jackstands may help. Try and keep it as clean as possible, including the underside (at least of the engine). Some people would be right at home with your personal driving conditions, you know, the whole off roading, Jeep Wrangler driving type?

I've seen vehicles from the northeast come down here. Frames and underbody are completely rusted, to the point of almost falling apart. This is obviously because of the harsh winters they have up there. Basically I'm saying, it may be impossible to avoid future repairs because of your own personal driving conditions.

[SpringfieldSkins]

QUESTION:

2003 Saab 95 wagon, every time I turn on the AC all my coolant spills into the road and bells and whistles start going off on my dashboard. I refill, drive without AC and everything is fine. Next day, wife gets in car(not knowing about AC problem) same thing happens. How much is this gonna cost me?

Thanks in advance.

Again, with the cost... It's very hard to say, location and actual problem have a lot to do with this. I will however note that Saabs are pretty damn expensive to work on, just an FYI.

It sounds like possibly the AC is somehow putting up so much strain on the cooling system that it's causing the car to overheat. The strange thing is that after you fill it back up and everything is fine. I'd think maybe thermostat (coolant is not circulating because the thermostat won't open or is sticking) or water pump (coolant is not circulating enough). I'd personally lean more towards thermostat as your problem.

You should take it to a reputable service station though. See what they have to say.

[SpringfieldSkins]

I agree with this. As soon as a service person tries to sell me a power steering flush I typically will never go back to them. I always thought that was BS. Apparently, my suspicians were correct.

Question. My girl has a 97 corolla with 90K, which should get in the 30's in terms of mpg. I bet it gets in the low 20's at the moment, horrible. I changed the plugs and wires, no effect. What should I do next? Fuel system cleaning?

A power steering flush isn't always useless. I've seen many times (especially on Fords), a power steering flush clear up a power steering whine. I has also been proven to prevent leaks in power steering components. Not saying you should do it every day, but a little maintenance now may prevent a $1200 power steering rack replacement.


As far as the mpg issue. Check tire pressure, check air filter, check throttle body. The first two are easy, as far as the throttle body, if it's dirty (you'll see black stuff all over it, especially the back side if it is) than you should have an induction service. Adding a can of injector cleaner to the tank probably won't do the trick. There are machines used to perform this induction service. Basically those machines atomize the chemicals and spray right into the throttle body, atomization looks like a fine mist by the way. Other chemicals go into the vacuum lines and clean those out too. Final thing to check... they way she drive the thing. Does she drive like a maniac? That would hurt fuel economy too, quite a bit I might add.

[SpringfieldSkins]

...

Probably cost near as much as the car is worth, but having JUST bought my wife a new one, and a baby due in 6 weeks I'd glady spend the $2-$3k if it will keep me going at least another two years.

Thanks man. Great thread that clearly a lot of people are getting good use out of.

Congrats on the baby! Or at leas soon to be born baby!

If I were on your shoes, I'd drive the car untill it failed in a forward gear (starts slipping I mean). It only happens in reverse for now, so you should usually be able to get where you are going. If you flush it, it could make it worse (to the point where reverse doesn't work or the forward gears are also affected), or have no impact at all in which case you basically wasted your money.

With a newborn on the way, I know every last penny you could save would be for the best. I'd rather not see you waste your money, if a transmission flush could accelerate the rate of failure of your transmission or have no affect on your transmission's symptom at all. Based on my experience, transmission flushes don't usually help Honda's that show signs of failure.

Also, I understand that you don't want a car that isn't reliable. So if your willing to spend the several thousand now, for a new transmission (if that's really what it needs), it's completely understandable.



Also... thanks for your comments. Hopefully I didn't bite off more than I can chew with this thread. I've spent about 2 hours just answering questions and commenting. Haven't even had time to check out the religious/political mumbo jumbo on the Tailgate boards yet. It's fun though, I like helping people learn and educating people in the field that I chose to persue.

[SpringfieldSkins]

Now for some Goalline blitz... whew!

Check out the statline of my RB, Runny MacRun. Tomlinson what?
http://goallineblitz.com/game/game.pl?game_id=43425

[Fear Our D!]

I own a 2004 Nissan Altima 2.5 S with 76,000 miles on it. I get the oil changed every 3k. But what other services may it need now with these miles on it? For some reason it seems like 75,000 miles is a familiar number for maintenance on a car. And also, my car has a timing chain, correct? Thank you, sir.

[SpringfieldSkins]

I own a 2004 Nissan Altima 2.5 S with 76,000 miles on it. I get the oil changed every 3k. But what other services may it need now with these miles on it? For some reason it seems like 75,000 miles is a familiar number for maintenance on a car. And also, my car has a timing chain, correct? Thank you, sir.

It sure sound cliche, but since I don't have my trusty computer software here (the guide that tells me all of the maintenance intervals for every car), I'll have to say, consult the owners manual.

75K probably entails something along replacing the engine air filter, the cabin air filter and replacing the oil and oil filter. I can't be too sure though. 60K and 90K are probably more necessary (read: contain a lot more maintenance needs) than the 75K service. 105K is probably going to be fairly large as well I would assume.

Also note... if you haven't had any maintenance done at all, except for the normal oil changes, expect bad news with all of that stuff that says "inspect" next to it in the owner's manual for 75K.

[Fear Our D!]

It sure sound cliche, but since I don't have my trusty computer software here (the guide that tells me all of the maintenance intervals for every car), I'll have to say, consult the owners manual.

75K probably entails something along replacing the engine air filter, the cabin air filter and replacing the oil and oil filter. I can't be too sure though. 60K and 90K are probably more necessary (read: contain a lot more maintenance needs) than the 75K service. 105K is probably going to be fairly large as well I would assume.

Also note... if you haven't had any maintenance done at all, except for the normal oil changes, expect bad news with all of that stuff that says "inspect" next to it in the owner's manual for 75K.

Alrighty. Thanks for the info.

[SpringfieldSkins]

Alrighty. Thanks for the info.

Glad I could help.

[Shilsu]

I recently had an AC leak repaired. Things were fine for a couple weeks. Lately, I've noticed it sounds like the fan is on when I have the AC off, but no air is blowing out. What is that?

[SpringfieldSkins]

I recently had an AC leak repaired. Things were fine for a couple weeks. Lately, I've noticed it sounds like the fan is on when I have the AC off, but no air is blowing out. What is that?

Sounds like the fan in the dash (blower) or fan under the hood (radiator fan)? If it's the radiator fan, than that's normal, it comes on after the car warms up to help keep the radiator at a constant temperature. If it's the blower in the dash... do you have the interior fan on at all? How would you describe the sound?

It's highly unlikely that they disturbed anything while fixing an AC leak as far as the blower is concerned. Unless they were in the dash replaing the AC evaporator of course. Also, if there was a problem with what they did it would most likely have happened soon after the fix (within a day or two).

One question though. Does it sound like a wooshing sound, like air or water rushing from behind the dash? Most likely after you turn the AC off?

[Shilsu]

Sounds like the fan in the dash (blower) or fan under the hood (radiator fan)? If it's the radiator fan, than that's normal, it comes on after the car warms up to help keep the radiator at a constant temperature. If it's the blower in the dash... do you have the interior fan on at all? How would you describe the sound?

It's highly unlikely that they disturbed anything while fixing an AC leak as far as the blower is concerned. Unless they were in the dash replaing the AC evaporator of course. Also, if there was a problem with what they did it would most likely have happened soon after the fix (within a day or two).

One question though. Does it sound like a wooshing sound, like air or water rushing from behind the dash? Most likely after you turn the AC off?

It sounds like the fan in the dash in the vents, despite having turned everything off and no air blowing out. It sounds like when I'm defrosting the windshields. If there's going to be a long-term consequence, that's gonna be another headache. If it doesn't really matter, I don't care.

Thanks for the help.

[SpringfieldSkins]

It sounds like the fan in the dash in the vents, despite having turned everything off and no air blowing out. It sounds like when I'm defrosting the windshields. If there's going to be a long-term consequence, that's gonna be another headache. If it doesn't really matter, I don't care.

Thanks for the help.

If it happens after you use the AC but turn it off, this may be normal. There can be a sound of the AC rushing through the evaporator after you turn the AC off.

You could possibly take it back to the people and say, "My car started making this noise, you guys fixed it a few weeks ago, can you come outside and hear it?" a reasonable shop would go listen to it on the spot as long as you think you can duplicate the noise. They shouldn't charge you anything for just listening to it either.

[Shilsu]

If it happens after you use the AC but turn it off, this may be normal. There can be a sound of the AC rushing through the evaporator after you turn the AC off.

You could possibly take it back to the people and say, "My car started making this noise, you guys fixed it a few weeks ago, can you come outside and hear it?" a reasonable shop would go listen to it on the spot as long as you think you can duplicate the noise. They shouldn't charge you anything for just listening to it either.

Unfortunately, it does it when I start my car, too.

Thanks, I'll probably be doing that sometime soon.