DH6twinotter

Hey all,
I have had some spark knock (pinging) for a while now. Well, I took it in to the shop and they ran a diagnostic on it because the check engine light was on. Turns out my knock sensor was bad. So, I waited till the semester was over, and got around to fixing it. What a job that was. Anyhow, that didn't solve the problem and it is now knocking more than ever. :mad: It's driving me insane. Here's what I've done to try to fix the problem:

Bosch (sp?) spark plugs
02 sensor
Knock sensor
knock sensor wire

That's about it. Any ideas of what could be causing this? As far as I can tell, my timing is right. I use mid-grade gas. That helped things a lot before I did the knock sensor repair. Now it's knocking all the time. It doesn't do it too bad when my engine in cold. It gets worse as the engine gets warmer and when driving between 40 and 55mph.

Replacing the knock sensor did solve the check engine light and the truck runs smoother then it did before. It's not as hesitant as it used to be, but the knock is a lot worse than it used to be.

Anyhow, sorry for rambling on here. This is really starting to annoy me.

Thanks for any help.
Have fun.
DH6twinotter

L33T35T 4Runner

what brand gas are you using?

DH6twinotter

I use mostly Citgo, altough I use BP/Amoco too. I don't use any of that cheaper stuff regardless of how much lower the price is.

Have fun.
DH6twinotter

Toddski

I know what you mean.
I had the same problem on my GMC Yukon. It was driving me crazy
A guy that i work with purchased one of those fuel injector cleaners that you hook up to your fuel rail and run a solvent to the injectors.
This worked out great on my Yukon. My 4runner is knocking and i need to do a flush on it.
I'll post the results as soon as i get around to doing it.

DH6twinotter

Does that techron (or whatever it is called) work good? Is that fuel injector cleaner?

My truck doesn't seem to be knocking as bad now, but the wheather has been quite a bit colder. It's suppose to warm up tomorrow, so I'll see how it runs then.

Anybody have any more ideas?

Have fun all.
DH6twinotter

Jay

Check the EGR valve operation. Ping can be caused by exsessive heat. And the EGR's sole purpose is to reduce combustion temperature to lower NOx gases.

DH6twinotter

Thanks for the reply. I got a question: How do I check the valve operation? Sorry, for sounding like an idiot here.

Have fun all.
DH6twinotter

Jay

Find a vacuum source that has vacuum at idle. Take a vacuum hose and apply vacuum to the EGR valve itself. If the engine stalls or is very close to stalling, you can be certain the EGR tubes are clear of restriction.

Next using a vacuum gauge, test the vacuum source to the EGR valve by reving the engine up to about 2500 rpm or so. You should get a strong vaccum signal which will probably cut off on you due the ECM determining there is no load on the engine.

DH6twinotter

Thanks again. I actually have already done that. It was on accident. When I was putting everything back together, I put a few of the hoses in the wrong spot. Turns out one of them was the one going to the EGR valve. Car wouldn't keep an idle, unless the hose was disconnected from the plenum. So, left it unplugged and drove it home to figure it out the next day. I plugged the hole (the one on the plenum) with a stick.

Anyhow, I guess my EGR valve is working right. Now I just need to figure out why it is still knocking. And what to do about my leaking radiator (which just started right after the knock sensor replacement). *sigh*

Well, thanks for all your help.
Have fun all.
DH6twinotter