02 Altima engine wont turn over and high idle

I have a 2002 Nissan Altima with 98,000 miles on it. It has given me plenty of trouble in the 4 years since I got it from my parents.

Breif history:

60,000 miles: had to have the engine rebuilt because I blew a head gasket? But I drove it from Baton Rouge to Houston just fine before taking it to the dealer to get the oil changed. They told me I had to have the engine rebuilt…unsure what caused this because I regularly changed oil and had maintenance on it. anyways.

88,000 miles: alternator replaced (did myself with the help of the hubby)

95,500? miles (3 months ago): new carborator (sp?) and 2 new O2 (oxygen) sensors

1 month ago: new battery

Recently, the car has been idling higher than usual (it is only at the 1 but it usually idles closer to 0 rpm). This 1 rpm idle starts from a cold start frist thing in the morning in park, but it now idles high all the time.

Friday, the brake light came on (which according to the manual means the break fluid is likely low).

Today my engine wouldn’t turn over. It tried and tried. No lights were left on, keyless entry worked, inside lights worked. When I floored the gas, the car finally turned over.

My questions:

1. What may be causing the car to idle at to high an rpm?

2. What could cause the car not to turn over?

3. Is the problem causing the high idle a major ($$$) fix?

I guess I’m at a point where the hubby and I are unwilling to sink any more money into this car since it seems to be all failing… but everything has recently been replaced so it may have a few more miles in it…

Any advice is greatly appreciated

There are so many possibilities, that I could go on for ages.
I will try to make this as simple for you as I possibly can.

Start with the spark plugs.
When was the last time they were changed?
Might be time for a new set.

The high idle can just simply be temperature related.
What has the weather been like lately?
What is the idle speed when the coolant gauge is in its normal position near the center of the gauge?

The idle speed can also be caused by a loose connection between the throttle body, and the intake manifold, or between the intake manifold and the cylinder head, or a loose vacuum hose that attaches to the intake manifold or the throttle body. It takes a bit of effort to hunt down this type of issue.

Or it could be that the Mass Air Flow sensor is starting to fail.

But here’s something you and your husband can try in the mean time to see if it helps:

  1. Drive the car to “warm up” temperature.
  2. Ensure any battery draining devices are off. Ie. headlights, interior dome lights, HVAC, stereo.
  3. Turn the car ignition key to “OFF”
  4. Wait ten seconds
  5. Turn the key to “ON” (not start)
  6. Wait three seconds.
  7. Perform the following five times in five seconds or less. Fully press the gas pedal and release.
  8. Wait seven seconds from last of the five releases.
  9. Fully press the gas pedal and hold down. Within ten seconds the “Service Engine Soon” light should begin to blink.
  10. Wait another ten seconds (while still holding the gas pedal) and the “Service Engine Soon” light should stop blinking.
  11. As soon as it stops blinking, release the pedal, start the car and check the idle (should still be around 700 rpm)
  12. Let the car idle at 700 rpm or so for about 25 seconds, rev the engine a few times and then let it return to idle.
  13. Shut the car down.

You car has now relearned the new air volume, which should be different than it was (stock). You may notice a bit of a rough idle for the next 20 miles. This is normal and will go away. The reason you should make sure idle is around 700 rpm (full warm up) is because the car measures the air curve in relation to idle, so you don’t want to confuse it.

Give that a try and see if it helps.


Also, one last, and REALLY important item.

Take your car to a local mechanic, and have them remove the exhaust header/catalytic convertor, and see if the convertor material is damaged. If it is damaged, you will need to replace the header with another one.

If the material is damaged, it breaks apart, gets sucked into the engine, and causes damage to the cylinder walls of the engine, causing very high oil consumption issues, and eventual engine performance issues.

If you are having to replace a lot of oil in less than a couple thousand miles, this damage might have already occurred, and could be responsible for the idle issues.

This was a common issue on '02, '03, and some '04 Nissan Altimas with the 2.5 4 cylinder engine.


First off, this car has no carburetor. It is fuel injected. Do you mean a new throttle body?

Secondly, did you visibly check the brake fluid? This car should have an opaque brake fluid reservoir on the master cylinder, so checking the fluid doesn’t require getting your hands dirty.

If the fluid level is near Min, add fluid will probably turn the light off. But, you may need brake pads soon. As the brakes wear, fluid is used to take up the loss in pad thickness. Most of the time, when the light goes on due to low brake fluid, the pads are almost fully worn out.

If the fluid is near Max, your having a potentially dangerous brake problem and should have a qualified mechanic look at them ASAP.

To answer the questions,

  1. High idle can be caused by a vacuum leak, a sticking Idle Air Controller, or an engine that doesn’t heat up properly. Only a proper diagnosis can find the problem.

  2. If you must ‘floor the gas’ on a fuel injected car to get it to start, it is usually a sign of a flooded engine. This is most likely due to a leaking injector. If it happened just the one time, it’s maybe not a real issue just yet. If it happens frequently, you’ll need to get this fixed. It should be easy to find the bad injector by looking at the plugs after another episode.

  3. Depends on the problem. A broken vacuum line is cheap. A new IAC may be costly. Just cleaning the IAC and Throttle body is cheap. A cool engine may be due to a bad thermostat, which should be cheap.

I’d have these issues diagnose and a price quoted before condemning the car. You may have been swindled on the rebuild, but 40,000 miles ago, that’s pretty much a lost cause. These new problems may be dealt with quickly and inexpensively.

High idle can be caused by a vacuum leak, a sticking Idle Air Controller, or an engine that doesn’t heat up properly.