1990 Toyota Camry Engine noise upon acceleration

First, I doubt it is piston slap. If it was, you would hear it most when the engine was cold. Metal, unlike water, expands when it gets hot. Therefore, if there was excessive wear in the cylenders causing the slap, you would be more likely to hear it cold.

As far as carbon on the top of the pistons, if there was enough to do it, all that would need done is a carbon cleaner that is injected into the engine like an I V from a doctor. The I V is placed into a vacuum line such as the power brake booster vacuum hose and it drips into the hose and through the engine cleaning out carbon. When it's done, you will see a ton of black smoke come from the exhaust if carbon is the problem.

My suggestion is to have another mechanic listen to it. I am confident about the piston slap, and the carbon can be taken care of without taking anything apart on the engine. Also, if you have kept the oil changed at 3K miles on a regular basis, the engine is just getting broken in.

Let me know if you have other questions.

Joe

Darrin:
What I would suggest is getting a second opinion. I'm not there to hear it, but honestly, piston slap is at its worst when the engine is cold, and yes there are products to clean carbon from the engine.

If you get a 2nd opinion, get it from a different mechanic. That is what I recommend.

Let me know what the second mechanic says.

The best way to clean carbon build-up out of your engine is NOT to take the car out and run it as hard as you can. This only results in meetings with local law enforcement personnel, and doesn't do much for cleaning out carbon.
If you really want to clean the carbon out of your engine follow these simple steps. Fill an empty soda bottle with water. Remove your air cleaner. Start your engine. While using one hand to control the throttle, trickle the water into the carb or throttle body with the other while holding your thumb over the bottle opening. Keep the engine rpm's up so that the engine doesn't die. Make sure that you don't pour the water in too fast! Water doesn't compress and if you pour too much water in, severe engine damage can result! White smoke from the exhaust is normal. If you have a port fuel injected car, you obviously won't be able to use this method, but I have had success with connecting a vacuum hose to a port at the base of the throttle body and sticking the other end of the hose into the bottle of water. The vacuum of the engine will suck the water in, creating the same effect. This will clean out even the most stubborn carbon, by 'steam cleaning' your cylinders.

Here is another:

on the subject of carbon cleaning, GM top eng cleaner works well. On cars, I feed some into a warm idling engine either thru the carb or a manifold vac source until the motor runs very rough or stalls. This coats the valves with the cleaner. Then I pull the plugs, and drizzle some onto the pistons. Let it sit till the engine cools. Cover the plug holes with a rag, and spin the engine over, expelling a nasty blast of top engine cleaner and carbon. Re install the plug and fire up. Away you go in a cloud of smoke, decarboned for the time being. Has never failed, at least to amuse me when I road test afterwards and blow out all the carbon and cleaner.

I've already given you too much to read, but seriously, there are ways to fix this problem without removing the engine. Heck, the water treatment is free. However, you would really have to trickle it in. Remember, water doesn't compress. If you put too much in, you could bend a rod or create other internal damage.

Go on the internet and google search Engine Carbon Cleaners. There are a lot of them that are available. I'm not allowed to recommend products by name, but there are many out there. It's worth a try. A friend of mine has a product he uses in his shop. THe product is actually set up like an I.V. At the hospital. It is run through a vacuum hose like the brake booster hose and slowly the engine sucks it in. You can't believe the black smoke that comes out of the tail pipe. It's unreal! Check it out. I know they are out there.

LEt me know if you find anything to try and if it helps, or if you have other questions.

Joe