Engine problem?

Question

im using esteem 2001 mpfi model, i am having problem with the engine , the RPM starts dropping & increasing in ideal position (engine gets vibration after each 10 to 15 sec.)& some time it comes down to 150 to 200 RPM also & other prob i m facing is during the first start in morning RPM goes to 1500 & if u run it for 5 minuts then also it will not come down, when u go about 1/2 km & you stop the car compleatly then heat indicator will raise & rpm comes down, i'hve explinded this two problems to authorised service centers also but thy r not getting exactly or may they are not be able to solve the problem, so dear sir, pl give me some tips, or suggetion regarding this issue it will be helpful for me
thanking you

Answer 1

Typical causes for an oscillating idle is a vacuum leak somewhere along the intake manifold. usually around some type of gasket.

High RMP at initial start up until the engine warms up is actually normal. After the engine warms up, the idle should go down, so what you are describing in the second part is actually normal for most cars.

Answer 2

Well, have you had to keep refilling the water in it lately because it sounds like it might be leaking water in to the combustion chamber. You should be able to see some sort of moisture come from the exhaust if this is the case. IT sounds like you might have a cracked head or faulty head gasket. It sounds like the engine is trying to compensate for the water being in the cylinder by adjusting the air, timing and fuel and when you shut the car off for a long period of time the water dissapears from the chamber and the cars computer is still adjusted in the morning when you get the higher rpm.

Do a compression test, check the plugs for any uneven burning on one of the plugs. Keep notice on when you put water in or if the water level is low.

Good luck.