Nobody

Heat shield hmm....gotta check that..

My knocking sounds like the same thing

blupaddler

knock...knock...

I have a 3.0 that just started doing the same sort of thing between 2500-3000 rpm. I can hear mine driving and when just standing still. My wife says I listen to my truck too much

But...I asked my mechanic friend about this problem, he said it might be the injectors. Something how if you use different brands of gas, some have more alcohol in them. Then something gets loose and gets stuck in the injector. Soooooo, I am currently trying a bottle of that fuel injector cleaner stuff. Which sounds a heck of a lot cheaper than a rod/rebuild for now. Hopefully this will work, I will keep you all posted.

Info about my truck: 1990 toy p/u 4x4 almost 198k miles...orig

MTL_4runner

I am not convinced at all that both of these truck have a rod knock.
Use some techtron injector cleaner (bust stuff besides a professional cleaner service)

Fink

Yeah...I'm not convinced its anything serious. I just got back from a little 30 minute joy ride on the highway and just pretty much anywhere I thought I could get it revvin pretty good. It only knocks between 3100-3600 RPM's. I would almost say its like a high-picthed "jingling" or...."tinkling" sound, or I guess maybe a high-pitched tick.

I'm not as concerned now as I was before...I am almost at the right level on fuel to where I can add some cleaner.

About that injector cleaner, is the Chevron stuff in the grey/black bottle made my Techron? If so then I can get it...if Techron and Chevron are two different things then I will have to use the Chevron as I cannot get the Techron brand around here...or atleast nowhere I have looked.

So...sounds like I'm going to be heading to the store here soon to get some injector cleaner, I'll add that and then fill up with some 91 octane gas from my normal gas station (I'm going with 91 octane because I have heard stories about the 91 performing better and I'm wondering if that will make it quieter)

Thanks for all the help..anymore advice would be great also!

Fink

MTL_4runner

I use the Chevron Techtron stuff that comes in a black bottle at Costco (comes in a pack of 4).

instntset

I have the same jingling type of sound that you describe between 3,000-3,500 RPM. Im assuming its not a rod bearing on mine becasue I just had a full overhaul less than 6,000 miles ago. I havent taken any closer looks at it and like some of you others have said I just assumed I was listening to my truck too closely and that it is a normal sound. I have also noticed that it only does this periodically and sometimes stops for weeks on end. For this reason the bad gas idea sounds logical too me. I dont think anything was done with the injectors when the engine was rebuilt but im not sure...

Fink

Well I think I'll go ahead and run that Chevron cleaner through just to make myself feel better about it.

Thanks for the advice, I'll keep you up to date if I find anything else wrong or the noise gets worse.

Fink

Fink

Well I went to the store today and got some Chevron Techron Injector Cleaner and put that in...then filled up with some 89 octane gas.

I was going to go to 91 but then I remember somebody saying that it can be bad to switch back and forth between different octane gas..any truth to this?

I'm not to sure that the knocking is really that bad, its kind of a chirping sound and it only does it sometimes. I don't think there is anything seriously wrong.

Thanks, as always, for the help!

Fink

MTL_4runner

I have heard that arguement but I don't buy it at all.

Fink

Me neither...in that case. I'm going to run this tank of gas down til the light comes on to make sure all of the injector cleaner has gone through and then I'll put in 91 octane gas and maybe some more injector cleaner if I feel I need it.

Thanks for the quick response MTL!

Fink

frost203

sounds like the same problem I got wit my 87 4Runner 22RE. I suspect either a knock sensor problem or lean condition. Mine has a ever so slight variation in RPMs, barely noticable. I'm going to have the injectors professionally cleaned in the next couple of days then if it still persists I am goning to have the knock sensor replaced. Let you all know how it work out..

-FROST-

Yoda

Chevron makes 2 kinds of FI cleaners. The best stuff is Techron FI cleaner. It smells like a "hot" chemical solvent. The one at costco is FI cleaner WITH techron. It smells like diesel.

I use the "hot" stuff once a year (the big 20 oz bottle), and the little costco bottles every month or two (I drive about 2500 miles a month)

Dan_90SR5

I can help with the rod knock portion on this. I spun a bearing on one of my rods and it is a very noticable knock at about 3000 RPM. If you have been driving on a spun rod bearing, you would be able to hear it slightly at idle.

Just some words to the wise about this problem in case anyone has it happen to them. This is a pretty cheap fix, not the $3K that someone posted(unless the dealership suggests the fix and does the work. You can drop the oil pan, take off the bearing cap/windage tray, remove and inspect all off the bearing, replace with new ones and roll(if caught early). If you have to rplace a rod, you're looking at a complete rebuild, which can be done as cheap as $1K or less if you do your own work.

I am an engineer and am not talking out of my on this one. I am currently rebuilding my 3VZ and it is going to cost me less than $1K, minus the custom goodies. More on that later though. I have a cheaper alternative to the 5VZ swap.

AgRunner06

I can't wait to hear it!

Fink

Well, after talking with my dealer and having other people listen for the noise I have concluded that it is just the normal 3VZE chatter. It is more of a ticking noise rather than a defined knock...I don't think its that big of a deal.

And after going today to get my Dynomax muffler installed...it is sounding REALLY good!

Fink

bomberyota

My 3.slow ticks too at 3000 rpms. I just live with it!

Cebby

This has been a great thread. Mine seems to have a knock around 2500-3000 under load. It is a knock, not a tick - I know the difference. Mine has the ticking noisey injectors/valvetrain also. The knock is different.

We make a habit out of getting the cheapest gas around. I'm going to try 89 and a bottle of FI cleaner. I haven't cleaned the injectors in...well, it's been a really long time.

I have the FIPK, but never remember knocking due to leaning out. BTW, mine only knocks when the engine is up to temp.