Quote:
Originally Posted by poundwise
Here's my view on oil changes: Every vehicle manufacturer that I've seen says between 5K and 7.5K for oil changes. The, every 3K or 3 months rule came about as a way to get people to buy more oil and pay for oil change service more often. Both of my vehicle manuals suggest 6K to 7K for oil changes, unless I drive in harsh conditions, then they suggest 3K to 5K. I do my oil changes between 4.5K and 6K, usually as close to 5K as I can (this works out well with the tire rotation schedule too.)
|
The conditions listed for "Normal" service is 50mph at 70 degrees F. Anything other than that is considered "Severe". I don't know anyone who drives their car under "normal" conditions.
Granted, part of it is marketing, but the oil change also gives shops a reason to inspect the car to find more work to be done. Not necessarily a bad thing. It depends on the shop.
Oil change aside though, everyone should visually inspect their car once a week to see if anything is wrong. An early diagnosis can usually prevent expensive repairs later on.
Quote:
Originally Posted by poundwise
Here's a real question for you. My Dad has a 1995 Geo Metro LSi, 4 cylinder. He drove it somewhere one day last week and then, when he went to leave, it would not crank. He had it towed to a shop. It is not the starter, ignition switch, alternator, nor battery. They claim that something is causing the car to have a rich mixture and is essentially flooding the vehicle out. (The smell of gasoline is strong after trying to crank it for a while.)
They are now looking for a replacement computer for the vehicle.
Do you think, based on this limited info anyway, that they are barking up the right tree? Or does something else come to mind that we may ought to check?
By the way, I know... its a 95 Geo Metro... but, still, he'd like to get it running.
|
When there is a crank but no start situation, you would usually look at fuel, spark, and compression/timing. Miss any of those 3 ingredients and the car won't run at all.
But you said it would not crank at all. Which leads me to believe that something in the car is preventing the starter motor from turning over.
A bad alternator doesn't cause a no crank because when you're cranking, the starter is running off of the battery, and not alternator current (when the engine is operating at low speed, the alternator doesn't make enough current). So provided your battery has a full charge, no crank is not related to the alternator.
I personally would start with the battery. Make sure the battery has sufficient charge. Sometimes a battery, old or new, that has been sitting a while will not be fully charged. Look for telltale signs of a weak battery like dim lights.
Next I would suspect the a bad ignition switch or wiring. The easiest way would be to unplug the harness at the starter solenoid. Then hook up a multimeter to the start signal wire. The wire should show current when you turn the key to start. If not then trace it back to the relay, switch, or the wiring along the way.
If everything checks out, I would suspect the starter. An easy way is to wire the battery straight to the starter solenoid with a switch. If it doesn't crank then there's something wrong with the starter. If it does then the igntion switch or wiring is bad.
If your mechanic can't diagnose the problem after that then take it a different shop.
My money is on a bad starter interlock relay. Usually you have to be in Park or holding the clutch down to start. If the switch is bad it won't know that you're in P or holding the clutch.
Now you say the car smells like gas. This would mean that it's a crank but no start situation.
You smell gas which means you have gas, but that doesn't necessarily mean you have the correct pressure. It's an easy check. The technician will hook up a fuel pressure gauge and see how much pressure the fuel pump is putting out. I would also check to see when was the last time he filled up on gas. If it's been over several months, the gas probably deteriorated and is now saturated with water. The fix would be draining the tank.
You say he went somewhere and came back, which usually means he filled up recently.
I would check spark. This is also an easy check. The technician will inspect the ignition wires while someone turns the key to start. It will be very obvious if you have sparks or not. The fix would be to replace the faulty ignition component.
If you have spark, then you check for compression and timing. A compression test is done by pulling the spark plug, plugging in the gauge, and cranking the engine. It measures how well the engine is compressing the fuel mixture. You can also do a leakdown test that measures how well the engine is able to maintain compression, but that's not necessary.
If you have bad compression, your engine is probably in need of a rebuild, which means you're better off selling the car or getting a used engine put in.
If compression is good, check timing. Your car has various sensors to tell the computer when to send the spark. Don't automatically assume that the computer is bad. It could be one of the sensors.
I would go through the procedures recommended by the manufacturer to diagnose a crank but no start before haphazardly replacing the computer. The computer is the most expensive part, and plugging a good computer into a car that isn't running right is a good way to fry the good computer.
In summary, I would have them check just about everything else before suspecting the computer. If they've done that then it's probably the computer.
To tell you the truth, I really dislike Metros. You can buy a Civic for a little more money and have a much more reliable car.