TinMan

I searched, not much about any knocking in these engines. So here goes.

I never drive my wifes 04 4.7lt 4runner unless we are taking a trip.

Today I had to move it early in the morning to let someone out of the driveway. It started nice, idled fine, no knocks ticks, or anything.

I let it run for minute, then dropped it in reverse. And that is when it started giving a deep knock, sounded like a rod knock. Took it out of reverse back to park and it went away. Dropped it back into reverse and it came back. I went ahead and moved it, but let it run for about 5 minutes and it went away.

I checked the oil and it was fine. Full and clean.

Later in the day we had to take a long trip to pick up my son. No problems.

While it was knocking I left it in park with the ebrake on and opened the hood. I thought it might be the fan or one of the pullies. it did not seem to be coming from the front of the engine. Sounded more to the back pass side top.

We have had it since new, dealer maintained until 100k, with oil changes every 5k, timing belt all that. I went through the maint schedule and matched it up with the receipts and all is good except it does not seem that the plugs have ever been changed. I was told by the dealer that those are 100k plugs. The maint book says to do plugs every 30k.

I asked the wife on the trip tonight if she has heard any knocking out it in the mornings, she said "oh yeah it has been doing that for about a month now. But only in the morning, not when I leave work at night." She said that if she lets it warm up for about 5 mins, it does not do it.

Tomorrow I am going to do an oil change and use 10/30, maybe lucas syn. Spark plugs, air filters, front and rear difs, and few other odds and ends that it is ready for. Will see if that takes care of it.

Any thoughts or experiences that may help me out.

Were do you check the ATF fluid on these things. I could not find the dip stick, and it is not listed in the owners manual. Just says not to mess with it unless there is a problem.

Also is the FSM for a 04 4runner available for download anywhere?

Anything special I should know about changing plugs on these engines?

I know it is a long post, but wanted to get as much info as I have right now out there.

Thanks in advance.

mtb_dood

What you are hearing is piston slap. As a Toyota tech. we see alot of complaints about this. When you call the Tech. assistance phone number the have a pre-recorded message regarding this. As far as the ATF I wouldn't mess with it, to check it is a lenghty process: First you need a scan tool to make sure you're at the correct temperature. Then you would look at the trans pan and you will see a drain plug and another plug that says "check". You remove both of these supposing you're at the correct temp. If there is fluid slowly dripping out of the check hole, then you're ok. However if it's low nothing will come out of the "check" hole. You will need a special tool to add any fluid. It's basically a jug with a built in pump and a special fitting you thread into the side of the trans and pump to add fluid. If you take it to a dealership chances are they will charge you around an hour labor to do this.

As far as the plugs only V6's are 30k plugs. However if you have 100k+ it couldn't hurt to change them, also cleand the throttle body while you're in there.

Hopefully that helps let me know if I missed anything.

TinMan

Understood on the piston slap. Are you saying that it is nothing to worry about?

I just got done with the 100k service on it, plugs, oil, filters, front/rear dif's, and transfer case fluids. I used mobil 1 5w 30 conventional oil. Thought the little bit thicker oil might help.

Plugs looked pretty good for having 110k on them. But it sure does run a lot smoother now. Hopefully will get another 100k out of it. The wife loves this thing.

Thanks

mtb_dood

Yes. I wouldn't worry about it, just let it warm up when it's really cold.

TinMan

After the 100k service with new plugs, and 5w 30 oil it does not knock on start up at. The wife said she has been letting it warm for about 1-2 mins before backing out and heading to work. According to the computer it is also up 3mpg. Was at 17.2 avg before, and is at 20.1 avg now. I think the little thicker oil has helped some also.

TinMan

Also want to let you know manuals for these trucks are limited. I bought "All Data" $26.95 at autozone. It is not a FSM, but pretty good for general maint.