Did I kill my car by revving when idle?

After changing the PCV valve, I decided to rev the engine to test if it was installed tightly. I noticed the engine was not hot yet, but I still revved the engine to 4000 RPM for about 20 seconds (the most stupid thing I have done), then I saw white smoke coming from the engine. I didn’t check if there was smoke out of exhaust pipe. After searching the web, I realized I might have damaged the head gasket.

The car is still drivable, and the temperature was normal during the driving. But I feel really bad since I have killed the engine. So, how much damage I might have possibly done to the engine?

Could you tell us the make, model, model year, and odometer mileage of this mystery vehicle?

Sorry, I forgot to mention. It’s a 98 Camry with V6 engine and 150k miles on it.

If the engine is having issues, it is NOT from reving it to 4,000 RPM for 20 seconds. Any engine will handle that without issue even if stone cold. Now, doing that every time you start it over several years can lead to issues, but NOT doing it once.

Thanks, kcurt. You make me feel much better :slight_smile:

The white smoke, if you saw it only at that instance, was condensation that was sitting in the muffler.

A PVC installed the wrong way can cause a motor to blow an already weak gasket, so triple check your work.

Is it still smoking after that one instance?

Later I revved to 2k+ RPM idle and saw light smoke out of the engine. The smoke is very light and I had to watch very carefully to see it.

“Later I revved to 2k+ RPM idle and saw light smoke out of the engine”

If you mean that you saw smoke coming directly from the engine, rather than from the exhaust pipe, then–yes–there is cause for concern.

I would suggest that you first remove the pcv hose, and either replace it or thoroughly clean it with an appropriate cleaning product; and of course that you verify that the pcv valve itself is good by shaking it (it should make a slight rattling noise when shaken).

If these procedures do not eliminate the smoke emanating from the engine, then you need to take the car to a competent mechanic (NOT to a chain operation like Midas, Meineke, Monro, Sears, Pep Boys, AAMCO. etc) in order to determine the source of the smoke.

"The white smoke, if you saw it only at that instance, was condensation that was sitting in the muffler. "

Galant–In his original question, the OP told us that, “then I saw white smoke coming from the engine. I didn’t check if there was smoke out of exhaust pipe.” I think that condensation in the muffler is not likely to be related to smoke that is seen coming directly from the engine.

Would be helpful to know what part of the engine the “smoke” came from.
Near the exhaust manifolds? Coolant hose? Valve cover?

We really need to know if the smoke was coming off of the engine, out of the engine (like through the oil fill hole), or out the exhaust.

Myself, I’d also be interested in knowing if you’ve been using any oil and of your coolant is staying full.

The good news is that your statement that the car is still drivable and not overheating suggests that you’re fine. Simply revving the engine to 4,000 rpm should do no harm whatsoever.

Hi, I am the OP. I am not sure where exactly the smoke came from. I saw smoke rise from bottom of the back side of the V6 engine. It’s smell-less. I have been closely monitoring coolant level and there was no significant drop so far.

I will take my car to a local mechanic when I get time and report whatever the result is to you guys.

Thanks to all.

Your engine (see attached) has an exhaust manifold in front of the engine and another in back of the engine, one 3-port manifold for each “bank” of cylinders. Each gets very hot, hundreds of degrees.

You also have a valvetrain over each “bank”, and a valvecover and valvecover gasket on each cover.

As en engine ages, the valvecover gasket loses its “compression” between the valvecover and the head. It can, and often does, weep oil. In addition, older engines like yours develop “blowby” from normal wear. That’s a condition wherein the rings don’t seal as tight as they did when new, due to wear and metal fateigue. This, combustion gasses can get forced by the pistins. This can causes excess pressure in the crankcase. This excess pressure also pressurizes the spaces under the valvecovers, as they’re open to the crankcase through the oil return channels.

This excess pressure can force oil past tired, weepy valvecover gaskets. That oil can drip down onto the exhaust manifolds and burn. It can also push oil throuugh the PCV valve, allowing ti to be ingested and burn. By revving the engine for 20 minutes you exacerbated the problem. Oil got pushed past the valvecover gasket and burned on the exhaust manifold.

I’ll bet lunch that that is what happened to you. I’ll also bet luch that you changed the PCV valve to deal with excess oil usage. Did I guess right? Or do I owe you a lunch?


to the same mountainbike: As I as know, I owe you the lunch! Here is what happened to my car recently.

Several weeks ago, I noticed oil leaking from valve cover. (Is burning smell caused by the leak?) I took my car to a mechanic shop and was told valve cover gaskets should be replaced. I got someone on craigslist to replace the gaskets for me. He replaced the front one and left the back one due to time limit. He also told me that PCV valve is leaking oil, so I replaced it by myself later. Then I tested the engine by revving it, and saw the smoke, as I said in the original post.

Today I took my car to the same mechanic shop, and they said the smoke came from leaking valve cover gasket, which I didn’t replace last time. Considering the coolant level has been consistent in recent days, the head gasket should be good. I don’t know whether piston rings are bad. Besides that, you are absolutely right!

Thanks for everyone here!

Not saying whether is or not something serious, but. If it is serious, it would have happened eventually. Even at 150 k miles, this motor is easily capable of an rpm that’s in all probability, is only two thirds of it’s redline. Take VDCs advise, but don’t blame yourself. 4k rpm is no worse then climbing a long hill while passing someone and forcing a downshift…l

OP said 20 seconds, not 20 minutes.

I wonder how one could check the pcv by reving the engine to 4k. Maybe you (the op) should let someone else do your mechanical work.

Camry V6 engines are known to have leaky valve cover gaskets. The leaks cause both smoke and odors. None of this was caused by your engine revving. No harm done.

The rear gasket is much more work to replace because parts of the intake manifold have to be removed.