I have a '97 4runner (3.4L) and it pings quite a bit. It is allright when I run 92 octane but even with 89 (chevron) it pings lately when entering the highway in 4th gear. The engine is also very noisy when I hold the gas pedal at the point that the engine is not working, but I am also not engine breaking.

The toyota dealer told me that it suffers from piston slap. Is that the noise I would hear. It is not noisy when its cold. All the symptons usually start when it is warmed up.

I did do the deckplate mod & have a amsoil filter. I also took out the "mufflers" from the air intake pipe.
When I hit the gas it seems to hiss a little. Is this common to other people who did those mods?
I read on the net that a plugged catalytic converter would do this to, but I don't know if the other symptoms go with a plugged cat.


I just changed the spark plugs (used to be bosch single ground tip) and I changed them with toyota plugs with the dual ground.

The truck has 140000Km (approx 90Kmiles) on the odometer. I feel i shouldn't have those problems. I don't really enjoy driving the 4runner lately and prefer the girlfriends golf. I don't like this trend and would like to figure out if the engine has a serious problem or it is something like timing, plugged cat etc.

I know this is getting long but I tried to get as many details as I can think about right now.

Hope somebody has some ideas

Thanks for reading so far
Arjan

 

Your engine definately has classic pinging under load symptoms.
I would take off the ISR mod and see if that cures the pinging.
I have almost the exact same setup and tried the ISR and it started pinging too so I went back to stock.
The deckplate mod should be fine and so should the amsoil filter.

 

I'm no expert, but here's my 2 cents:

1. timing not set properly or advance is defective
2. carbon build-up
3. Toyota's equivalent to an EGR valve is defective.

 

Thanks for the replies.

I just inserted the factory pieces to the air intake tube. The 4runner is for sure a lot less noisy. Kind of nice. I didn't notice any performance loss so maybe the loud sound just makes it feel faster!!.

It still pings I also looked for the egr but apperently mine doesn't have one. I checked the haynes manual and it show that some vehicles have it and others don't. Does that mean that my vehicle has another sort of exhaust recirc. system???

I already tried some stuff to decarbonate the engine. I am not sure if it did anything. The spark plugs I took out looked pretty clean.

I am afraid to bring it in to the dealership to let them try a lot of expensive part & procedure until they find it. The first thing they wanted to do is a fuel system flush to clean the injectors & they claimed that decarbonizes the engine.

I hope somebody can shine some light on my problems
Arjan

 

My first suggestion is to get a Snap On Motor Vac carbon depletion service. That will clean the injectors, intake valves, and the combustion chamber and will restore the truck to like new performance. It is called the Viagra for engines.

To check the cat to see if it is clogged is real easy. Hook up a vacuum gauge. note the vac at idle. The rev and hold the engine at 2500 RPM steady. The reading should be the same on the vac gauge or more vac. If it is less you have a valve timing problem or an obstructed exhaust.

Gadget

www.GadgetOnline.com

 

Gadget, can you tell us more about the Where can you get this done???

 

At any shop that provides the service. You may have to hunt around for it. There are other simular services, but the Motor Vac is the best bar none.

I had it done to my Maxima for the second time at 240,000 miles and it runs just like it was brand new. I have recommended it to lots of people and they ALL have reported a positive result.

Gadget

www.GadgetOnline.com

 

Thansk, I just got my emissions check done and the guy commented that I probably have a lot of carbon build up, which doesn' make much sense to me because I tend to "blow it out" quite often.

Maybe that will help me, what does it usually run ($) ???