Wow, I just tried out my new stethoscope ($5.99 at Harbor Freight). I was checking out the noise I described as a sewing machine on steroids driving back from LA yesterday. The valves don't all sound the same and I'll be looking into that a bit further. But, the real shock was how loud the injectors are when you put the stethoscope probe on the metal ridge around the base of the injector. BAM BAM BAM BAM BAM BAM BAM BAM BAM . . . . Man those things are loud compared to any other noise I could get probing the head/valve covers! Some are definitely louder than others. I'm curious, what makes so much noise?

 

Air or a lack of fuel.

Have you :

Recently had anyone remove a fuel line from the fuel rail ?
Got a dirty fuel filter ?
Got a leaking/poorly seated injector ?
Somehow degraded the injector o-ring that seals it in the head ?

Just a few to consider.

As always, a good quality injector cleaner used regularly IN THE GAS TANK will help these things out. Injectors suffer from gummy deposits in the gas.

I am still not so sure about cleaners introduced directly into the inlet manifold for cleaning injectors..I KNOW the fuel gets to exactly where it is needed.

Here is a tip, can't tell you why I know, lets just say I am in the supply chain... use Shell V power for a few tanks... see if it goes away.

The extra 20 cents per gallon is a lot cheaper than a proffesional injector cleaning service.

David

EDITED TO ADD :

My dearly departed 93 ran like crap when I bought it and the biggest improvement was a new fuel filter (genuine Toyota) , and 3 or 4 tanks or injector cleaner. Smoothed it right out and fixed the stuttering in the morning and improved starting.

David

 

Thanks! I should have mentioned . . . .

The injectors were cleaned and balanced with all new o-rings and grommets just a couple weeks ago. They were done by a pro at about $40 a piece. They were installed in my new Jasper. I was surprised at the clattering since Jasper claims they virtually eliminated valve train noise in their remanufactured 3VZE. I got the stethoscope to figure out what's making all the racket.

The fuel filter is new along with a whole lot of other stuff. How would these affect the injector noise:

"Recently had anyone remove a fuel line from the fuel rail?"
"Got a leaking/poorly seated injector?"
"Somehow degraded the injector o-ring that seals it in the head?"

 

Allowing air to be sucked in with the fuel.

David

 

Hmmmm . . . with all new o-rings and grommets maybe I'm just dealing with the horribly loud injectors these trucks are famous for. I guess I'll need go do some comparing. I wish I'd put the injectors under the stethoscope before the rebuild so I had a baseline.

 

The injectors on my 3.0 were rediculously loud. I took it to the local dealer and they said there was nothing wrong. I later replaced the complete engine w/a JDM engine and had the exact same noise.

The way I finally fixed mine was to run the 4Runner head-long into a pine tree at about 20 mph. Never had a noise after that!