while driving and steady on gas pedal, revs goes up unexpectedly...???

[[jeyps]]

I own a 2001 1.6 J Altis. I do not know why the revs goes up even I am steady on my gas pedal. Any one knows why and how to solve this?

I also notice that engine oil usually dries up. Is this normal?

[CivicVTi]

When was the car's last tune-up? You may want to have the idle air control valve (IACV) and air filter element inspected and cleaned. The same also goes for the mass airflow (MAF) sensor.

What do you mean when the engine oil dries up? Maybe you should have the valve cover removed and the internal components inspected for oil sludging/gelling.

[Alpha_One]

Might be a slipping clutch.

[[jeyps]]

Thanks CiviVTi for replying. I had my car tuned up last week. The last time I felt this was my 2nd to the last tune up. I had semi synthetic oil that time. I experienced this unexpected revs for several weeks and then it was gone. Just recently when I had my car to shell for change oil, it happened again. This time I used a regular oil and an addiditve so the oil will not burn up easily. (I think this is the common problem of Toyota's VVTi engines.) I googled IACV and found out that problems related to this component is stalling. Correct me if I understood it wrong, stalling is when the engine stopped for no intent reason while it is on. Fortunately, this was not my case. I remember one time, I was in Greenhills, window shopped for a couple of hours. It was very humid that time. When I was about to leave the parking lot and tried to start the engine, surprisingly, it did not start at all.. it was as if my battery is out. But I checked the headlights, radio, power windows.... and it seems fine. So I went back to the mall and spend an hour. When I get back... with tons of prayers... luckily, it started in just one click. I never enclountered the same problem until now.

I will try to check the MAF sensor the next time I will service my car * Toyota.

Engine oil usually dries up after 3 months. My usual ride from Monday to Friday is from Marikina to Makati. I have searched this problem on the net, and it seems this type of Altis engine is prone to oil drying. It was a factory defect according from those forums I read. What usually happens is the oil is burned with the gas. The thing is to always have it tuned up. I have used fully, semi synthetic oils but the same thing happens. I am quite sure there is no major leaks. No trace of oil drips in our garage. One thing I found out is the brand... for sometime, I used Petron, Caltex and Shell. Of the three brands, Petron regular oil seems to be the best. Well, at least the one which does not easily burned up compered with Caltex and Shell. About sludging, do you think engine flush will clean it as time passes? I mean after several oil change with engine flush and tune ups....?

When was the car's last tune-up? You may want to have the idle air control valve (IACV) and air filter element inspected and cleaned. The same also goes for the mass airflow (MAF) sensor.

What do you mean when the engine oil dries up? Maybe you should have the valve cover removed and the internal components inspected for oil sludging/gelling.

Might be a slipping clutch.

I will take note of this slipping clutch, Alpha_One. Thanks.

[ben_david19]

first rule of change oil, do not use different grades of oil (Mineral, Semi-Synth, Fully Synth) everytime you go for a change oil. better stick with one.

With the age of your car, I recommend for you to use Semi-Synth oils. Don't use any flushing material/liquid, it might damage your engine rings.

MAF sensor might be the culprit specially when your idle is erratic. In your case, this might be the problem but this is not a 100% guarantee that it will fix your problem.

I think your Altis is a fly-by-wire? meaning that car don't use any accelerator cable for the throttle. Might be the culprit too.

[ben_david19]

slipping clutch is a possible culprit too by the way (suddenly revs), although this wouldn't affect what you experienced before in greenhills (not starting).

[CivicVTi]

*[jeyp]

Actually the Altis' 3ZZ-FE engine is more known for gelling/sludging issues rather than oil drying (I'm assuming they are different). What is your car's mileage if I may ask? If you are in Manila, I suggest visiting Migs at SpeedyFix in Mandaluyong (http://www.speedyfixph.com/). Have him open your valve cover to inspect the inside of the engine. Most likely he can figure out what is wrong with your ride.

I drive around in a 2004 Altis E A/T (almost 70,000km), and I have never experienced any anomalies regarding the engine oil nor had idling problems. I always use Shell Helix mineral oil 20W-50, the one in the yellow container.

PS: Have the PCV valve inspected and the throttle position sensor (TPS).