1GR-FE 4.0L Motor Misbehaving

2006 Tacoma access cab, auto trans, 4x4... 65k miles... bought the truck 2 months ago... absolutely LOVE IT!!!!!

-- BUT --

Lately noticing an intermittant "pop" sound from the motor at speed 40-60mph... more often than not at the end of mild acceleration... almost sounds like a back-fire... just not nearly loud enough... in fact if I have the radio on, I don't hear it...

I'm thinking time for new plugs... any other things I sould be looking at?

 

Are you sure its from the engine?

VS something rattling or loose? Are you able to reproduce it? Can you 'feel' it pop? If you can 'feel' it....where do you feel it?

I had a popping sound also on passenger side while driving at normal speeds and not induced by anything - totally random while driving flat roads up at speed. I'm pretty sure my body mounts (behind the front wheel) were loose. I tightened them up to 50ft lbs and haven't had the noise since.....

 

I will crawl under again and check the body mounts... My first reaction was not to think it was engine...

Re-producable only that its most likely to happen after mild acceleration "at speed' i.e. up in the 40-60mph range

Feel it? Barely... more the sound that gets my attention...

 

Checked body mounts, they are tight..... Going to replace plugs next week unless any other ideas surface.

 

Unless you have records showing the plugs have been just done, they are due for the second time anyway. (every 30K miles).
Check for things rolling around under / behind the seats too, including the jack and tools.

 

x2 for a plug swap.

 

Great advice folks...

The procedure provided by chris4x4 http://www.tacomaworld.com/forum/technical-chat/30479-how-spark-plug-change-1-gr-fe.html

Made it smooth sailing... did it after I got home from work in just over one hour.

What was interesting was that when I pulled the plugs out, the gaps were wider than spec, but not terribly so... and looked proper with no oil etc... but they were 3 Denso and 3 NGK... so that tells me they were origional plugs - never before changed despite 65k miles on the truck.

Took a short test drive... seemed smoother at idle, at speed and under hard acceleration. (( But doesn't the truck ALWAYS seem smoother after a little work or a wash/wax.... I think its mechanics delusion!!! )) Did NOT notice the sound (popping) that got me started on this issue... but it was a "short" test drive... so tomorrow I've got a 180 mile road trip to make, with about 50% on the interstate... so it will be a good shake-down... will report back after that as well.

Again thanks to the group...