Car is shaky and rev is dropping when driving

[iflylo01]

Hello fellas,

I recently stopped bringing my car (2003 Camry LE) to the mechanic and started doing it myself. But there's a problem that is getting to me.

Whenever I drive the car it is a bit shaky and the RPMs does drop by a few hundred RPMs. Kinda jerky when moving. Do you guys think is the IAC valve, or the spark plugs, or should I clean the throttle body, etc?

Thank you

[Brian R.]

If you've never changed the spark plugs, change them. They could certainly cause loss of power. Is you "Check Engine" light on the dashboard on? If so, bring it to an Auto parts supply store who reads these codes and find out what code is stored in your ECM.

This behavior can be caused by many things.

[iflylo01]

If you've never changed the spark plugs, change them. They could certainly cause loss of power. Is you "Check Engine" light on the dashboard on? If so, bring it to an Auto parts supply store who reads these codes and find out what code is stored in your ECM.

Yeah, I will check out the spark plugs tomorrow. No, the engine light is not on. If it is not the spark plugs, what is the next possible solution? Does the spark plugs need to be gap? because in my owner's manual it didn't say. Or, does it come pre-gap to the specifications already? thank you

[somick]

Originally Posted by iflylo01

Yeah, I will check out the spark plugs tomorrow. No, the engine light is not on. If it is not the spark plugs, what is the next possible solution? Does the spark plugs need to be gap? because in my owner's manual it didn't say. Or, does it come pre-gap to the specifications already? thank you

No. The spark plugs do not have to be gapped. Denso or NGK (Toyota recommended) usually come pregapped from the factory.

I would also recommend cleaning the throttle body.

What mileage do you have on your car?

Good luck,
Sam

[Stealthee]

I always check plug gap and have found many "pregapped" plugs to be improperly gapped.

[iflylo01]

Originally Posted by somick

No. The spark plugs do not have to be gapped. Denso or NGK (Toyota recommended) usually come pregapped from the factory.

I would also recommend cleaning the throttle body.

What mileage do you have on your car?

Good luck,
Sam

My car just made the 150,000 mile mark a day ago.

[iflylo01]

Originally Posted by Stealthee

I always check plug gap and have found many "pregapped" plugs to be improperly gapped.

Do you know the correct gap for a 2003 Camry LE 4 cylinder? It doesn't say in my car manual

[Stealthee]

Should be .044

[iflylo01]

Originally Posted by Stealthee

Should be .044

Cool. Thank you. Another question, I notice every time I turn on my A/C, it makes the car rumble a little bit, is that normal? This is the only car I ever owned so I don't know if it's normal or not. If not, what is the fix?

[Brian R.]

Yes, this is normal. The A/C compressor puts a load on the engine.

[iflylo01]

So, when the car isn't moving while in Park or Drive, the RPMs look steady. But when the car is in movement, the car does jerk at times and the RPMs do drop a little. It is definitely the spark plugs or a dirty throttle body? Sorry guys, just need clarification because I need to know what supplies to buy tomorrow because I am poor and on a budget lol

[Brian R.]

It is not definitely anything. If the spark plugs have never been changed, then they need to be replaced with the correct NGK or DENSO plugs. Make sure you put a little antisieze compound on the threads of the new plugs and torque them correctly.

Cleaning the throttle body is simple if you are careful, and cheap.

One of the above two fixes is not necessarily going to cure your problem. They are only the obvious and cheap places to start. Once these have been done correctly, get back to us with the result. I would start with the spark plugs and see what happens. Cleaning the throttle body is more complicated.

If you want a third possibility, test the engine coolant temperature sensor. However, the above are more likely to solve your problem.

Thank you

[somick]

Originally Posted by Brian R.

Make sure you put a little antisieze compound on the threads of the new plugs and torque them correctly.

but do not put the antisieze on electrodes or you may shorten them!

Originally Posted by Brian R.

Cleaning the throttle body is simple if you are careful, and cheap.

I have read that one guy dropped a red tube from the throttle cleaner inside the throttle body. Be careful!

[iflylo01]

Just bought the spark plugs, but have a few questions before installing them tomorrow:

1. On the box, it says not to gap. The new spark plugs are around .041, but my owner's manual it says .043. Should I gap it to the manual's specifications or leave it as is? If I gap them and they are .001 off, will it affect engine performance?

2. It says not to use anti-seize on the box. I heard that white metal spark plugs, you don't really gotta use it or should I?

3. I don't have a torque wrench, can I just tighten it until it is snug tight? I know the cover it aluminum so I shouldn't put it on too tight. Should I buy one because it's important

4. My manual says Denso or NGK, but I accidentally bought Bosch, but the Autozone website says this will fit my vehicle and it is iridium-tipped. Should I install?

[somick]

Originally Posted by iflylo01

Just bought the spark plugs, but have a few questions before installing them tomorrow:

1. On the box, it says not to gap. The new spark plugs are around .041, but my owner's manual it says .043. Should I gap it to the manual's specifications or leave it as is? If I gap them and they are .001 off, will it affect engine performance?

2. It says not to use anti-seize on the box. I heard that white metal spark plugs, you don't really gotta use it or should I?

3. I don't have a torque wrench, can I just tighten it until it is snug tight? I know the cover it aluminum so I shouldn't put it on too tight. Should I buy one because it's important

4. My manual says Denso or NGK, but I accidentally bought Bosch, but the Autozone website says this will fit my vehicle and it is iridium-tipped. Should I install?

1. Leave them alone! Are you sure your gauge is that precise?

2. I use it anyway. Just make sure you leave two or three bottom threads clear of the antisease.

3. You do not really need a torque wrench. When you reach the block tighten the plug 1/4 turn and it will be enough. Your goal is to flatten the crush washer to seal the spark plug hole.

4. I have read many bad review about Bosch. You need Denso or NGK.

Good luck,
Sam