tercelrcr

Hey guys i hope someone on here can help me out. I recently had my motor compleatly rebuilt and it is running great, however it makes a funny noise when the motor is under a load like going up a hill or getting on the freeway. The noise is not very loud i dont think but it is a metalic sound. its kinda hard to explain but it will only do it when the car is under a load then it goes away. I hope this kinda makes sense, i was thinking it may be the axles but i replaced them both when the motor was rebuilt. any ideas???

andyz

This is certainly pinging. Pinging is caused by preignition or detonation. Because the engine relies on a volatile combustible gas to work, the system that manages this gas must be precise and in good working order. If there is too much heat, too much air (oxygen), a spark at the wrong time or too much compression generated by the piston, the gasoline will explode before the engine is ready. This causes the major brunt of the force from the explosion to not help the piston generate power for you, but instead hits it on its way up, causing a massive shock wave into the crank, etc.

Some ideas to get you started. Pinging has many many causes so you just have to be meticulous and cover your bases.

..use good fuel..fuels octane is its resistance to pinging..use the RIGHT octane.
..Check your ignition system. Weak spark can be caused by distributor, rotor, wires, plugs
..Check your ignition timing with a timing light...Proper spark timing is essential
.. Check all your airflow systems. Air cleaner, throttle plate, body, etc Too little or too much air can wreak havoc with the system.
..although most gas has fuel injector cleaner in it, try a bottle of injector cleaner. Too little fuel can cause a lean condition

....some others....
Make sure you are in the right gear. If automatic make sure your tranny is shifting down properly, if manual, if you hear pinging, try to shift down, try to stay in the power band for your engine,say 3500 - 4800 rpm.

Light pinging is ok and a fundamental design issue with engines. Consistent, heavier pinging is bad and theoretically will cause your engine bearings to self destruct.

!!!!!!MAKE SURE TO POST YOUR VEHICLE SPECS WITH EACH POST!!!!!!!!
Post your engine model, car model and any mods you have done...

for all I know, we're talking about your moped here,and my advice is worthless.

Checkmarks

Pinning sounds probable.

How to test if your motor is pinning:

First easy one is to check your timing with the old automotive timing light. Set the timing in accord with specs. Don't skip this step it may solve your problem before it starts costing money.

Run the current tank of fuel near the E on the gauge. Next Find the highest octane fuel in your reasonable vicinity. Get out your wallet (or dig in your purse) and fill it up with a tank of the good stuff premium. Take it for a good drive and put the car back under the conditions you called "funny noise under a load".

Hope this does not solve your problem, its going to cost you more at the pump for the rest of the car's service life. Pinging is detonation it does REALLY ugly things inside of your motor.

tercelrcr

Ok so sorry for forgetting the vehicle info. it is a 95 civic ex it has a d15b7 block with a d16z6 head running a d16z6 ecu with a base map tune. Has intake and exhaust. I have been running only plus which here in the nw is 89octane. Doubtful its weak spark new plugs new wires new distributor all in the last 3months. As for the timing how would i check that? i have no timing light would i need to go to a repair shop to have this done? Any fuel cleaner work better than others?

andyz

They have a timing light at harbor freight for $15. Parts stores have them for $40 or so. It's an investment.

Is pretty straightforward. You may need to check for your ecu and other mods, but basically, you set the ecu in check mode by connecting a piece of wire between two terminals. Mine is green and brown wires iirc.

You connect the timing light to the battery to give it power, then you take the inductor sensor and clip it around the #1 spark plug wire ( closest to the belts). Then start the car. The check engine will come on telling you the ecu is in check mode.

Then take the light and shine it at the crank pulley ( biggest pulley , goes right to the engine ). There are little *****s and paint marks on the pulley.

As the engine sparks the #1 cylinder the timing light will shoot a pulse of light onto the crank pulley. where this light hits as the pulley is moving tells the relative 'timing' of the spark versus the crank position. It should match the marks on the pulley. Middle one I think. There are three.

To adjust you have to loosen the distributor mounting bolts and slide it on it on is pivot forward and back.

Schister66

I agree...either pre-ignition or detonation. Buy a timing light and check your base timing