knocking noise coming from engine

[brock]

Hello, My 98 Tacoma (107k mi). starting making this loud knocking noise today. It appears to be coming from the upper engine area. I had just put some Lucas injector cleaner in with a gas fill-up about 20 minute before the noise started. I can't imagine this would be the cause. Any idea's on what could be causing this?

[RobD]

I have an 02, PreRunner...V6...when it warms up I have a "knocking" noise as well..I'm at 161000...it's been doing it for a while...only makes the noise when it's in drive or reverse (auto trans, obviously)...I thought the noise was from the transmission...then the upper engine...it's a mystery to me...would be curious to know what you discover...other than the noise (only noticable when stopped) the truck runs great...

[David]

brock wrote:

Hello, My 98 Tacoma (107k mi). starting making this loud knocking noise today. It appears to be coming from the upper engine area. I had just put some Lucas injector cleaner in with a gas fill-up about 20 minute before the noise started. I can't imagine this would be the cause. Any idea's on what could be causing this?

Did you ever figure out what was causing the knock sound? I've got a 2001 2.7 that started knocking after I also used the injector cleaner. Some say its a timing chain, others...valves, I just don't know.

Any luck with yours? I've now got 158k on my 2.7

Thanks

[bajabird95]

RobD wrote:

I have an 02, PreRunner...V6...when it warms up I have a "knocking" noise as well..I'm at 161000...it's been doing it for a while...only makes the noise when it's in drive or reverse (auto trans, obviously)...I thought the noise was from the transmission...then the upper engine...it's a mystery to me...would be curious to know what you discover...other than the noise (only noticable when stopped) the truck runs great...

have the exact same problem with 2001 d-cab 95k miles. please if anybody knows what the deal is let us know.

[Daniel]

I have an 01 prerunner v6 with 140k miles and when the engine warms up and is idling at around 800 rpm, i hear a knocking noise. i only hear it when it is idling though. i was thinking it was the transmission. i have no idea now. if anyone knows or has an idea, please let me know.