dusty98

I've searched previous posts on this and still haven't found an answer. If I missed one, just re-direct me:

Here's the problem:
90 4Runner with 219K pings at and above 3000RPM. Primarily noticeable on the highway at 70-75, highway driving is my primary driving.

Here's the repair history:
125K Toyota did the headgasket recall, decked the heads, replaced the piston rings, adjusted the valves and replaced the timing belt. 60k later, I had the timing belt replaced, waterpump, & thermostat. Truck ran like new after that and still runs good.

I started noticing the pinging after since moving to Florida from Colorado a few years ago. The fun part of this problem is that it comes and goes so just when you think you've nailed it, a few months later it shows up again.

I've had the O2 & EGR replaced, both tested bad. Had no effect on the pinging. Most recent attempt was a different mechanic who decarboned the intake and injectors, cleaned the throttle body, retarded the timing to normal and replaced the temperature sensor.

I run NGK plugs, Mobil 1 synthetic oil, K&N air filter, have the 5 speed manual tranny and 4:88 gears with 32" BFG's. I run name brand 93 octane gas consistently.


The truck runs fine, good gas mileage, don't notice much oil usage. Just this noise is annoying.

Any suggestions or experience would be appreciated,
Thanks

Corey

iTrader: (1)

I can only think of one thing, but then I am no mechanic

Mine use to ping too on the highway when accelerating.
Turned out my timing was advanced just 2 degrees.

The 3.0 engine likes to be set at factory specs at 10 degrees.

Once my timing was set back to stock, I have not had one bit of ping.
I also have to run 91 octane in this beast.
That can be contributed to carbon in the heads thus raising the compression ratio a tad.

One day I'll get the Snap On Motor Vac treatment which clears the upper combustion chamber of carbon buildup.

dusty98

Thanks,
I read earlier posts regarding timing settings and how to do it. I'll grab a timing light and check that out.

DH6twinotter

I've got the same problem except mine only pings when the engine is starting to lug. It does it mostly when stating at a red light, and climbing hills right before the tranny downshifts. It does do it some at 70-75mph like yours, but not really a whole lot. I run mid grade gas in it. I took it to a mechanic, and he said it needed a knock sensor. It was going to cost me $300 in labor to get to it, so I'm going to attempt it after the semester is over. A little more and that's almost enough to get some descent rims!

Well, that's the story on my 4Runner.
Have fun.
DH6twinotter

az4x4runner

What does the pinging sound like? Because mine makes ticking type noise and my local Toyota dealer told me it was most likely just the fuel injectors. I'm not sure I've ever heard pinging, so whats it sound like?
-Bryan

Dr. Zhivago

You know what a diesel engine sounds like? Pinging sounds very similar to that. A muffled crackling in the engine.

Dr. Z

az4x4runner

Thanks, was just curious, and I'm pretty sure my ticking is not pinging lol.
-Bryan

tkrispin

The ticking sound is the injectors...

DH6twinotter

I've heard pinging described as a bunch of marbles in a tin can. Pretty good description I think.

Have fun.
DH6twinotter

dusty98

There's definitely a difference between a ticking and pinging, you'll know it when you hear it.
Personally, I call it annoying. Considering that's the only thing wrong with my 4Runner, I can't complain.
Still a great truck
Thanks for the responses I'll let you know what I find.