2002 Toyota Tacoma 4 cyl engine knocking

[jwrobel0398]

I purchased a 2000 Tacoma 4X4 Ext. Cab w/2.7 liter engine in early summer of the same year. After the winter began to set in I noticed that after starting the vehicle I heard what I would call, "valve rattle" for about 1 1/2 to 2 minutes. I took it to the dealer and they of course told me this was normal and not to worry. Keep in mind, I was a ground support equipment mechanic in the USMC and worked on just about every type of engine there is and this is NOT normal. After doing some research and coming upon a site called, "Consumer Affairs" I noticed a lot of other folks were experiecing the same problem. My original suspicion was that the upper cylinder head was not receiving adequate lubrication until the oil thinned out and got up into the chambers. I did some research and found that this was a common problem in thier older engines and was suppossed to have been rectified. In fact, there was a site selling replacement parts to solve this problem. The problem being that Toyota went from a dual sproket driven timing chain to a single sproket timing chain. Note that the tension in the chain is driven by the oil pressure and when the oil is thick it does not correctly adjust the tension causing slack and the chain was slapping around in the housing and eventually wearing into the coolant chamber and eventually dumping coolant into the lubrication passages of the engine causing engine failure. After three trips to the dealer and being told that since I had documented the problem, if the engine ever failed it would be covered. Well low and behold at around 46,000 miles the engine took its proverbial dump. I of course had it towed to the dealer and was told that yes the motor had failed but not for the reason I stated and it would cost me $4000 to have it rebuilt. I of course had it rebuilt as I had intended to keep this vehicle for a long period of time because after all, these trucks were suppossed to last forever. Not to mention I babied the crap out of it and didn't want to go through the whole process again. I went through their arbitration and after a year was told I didn't prove my case even though I had the documentation from the dealer that I had it there three times with the same complaint all arounnd the same time of year when the symptoms would appear. I also noticed in the hottest months I could hear the same noise for a short period of time upon rapid accleration from a dead stop. Once again showing the oil pump was not functioning properly in providing adequate lubrication. After the engine (top end) was rebuilt the engine still makes the same noise and I'm waiting for it to blow up again. I feel sorry for anyone that has had to go through this debacle and I can tell you I will never purchase another Toyota again. Now we have the rust problem which I will soon be taking to the dealer to have the frame inspected. Good luck to you folks and let me know if you hear of any class actions started in regard to this problem and feel free to contact me via my e-mail.

[jethro790]

I have what has been called piston slap from two dealers as well on my 04 2.7l Tacoma. Motor knocks for a few minutes when it is cold out, only at startup. Truck has 120k miles on it now, so I guess the dealer was right, it is not a problem after all.

[tacoma2000]

Originally Posted by jwrobel0398

I purchased a 2000 Tacoma 4X4 Ext. Cab w/2.7 liter engine in early summer of the same year. After the winter began to set in I noticed that after starting the vehicle I heard what I would call, "valve rattle" for about 1 1/2 to 2 minutes. I took it to the dealer and they of course told me this was normal and not to worry. Keep in mind, I was a ground support equipment mechanic in the USMC and worked on just about every type of engine there is and this is NOT normal. After doing some research and coming upon a site called, "Consumer Affairs" I noticed a lot of other folks were experiecing the same problem. My original suspicion was that the upper cylinder head was not receiving adequate lubrication until the oil thinned out and got up into the chambers. I did some research and found that this was a common problem in thier older engines and was suppossed to have been rectified. In fact, there was a site selling replacement parts to solve this problem. The problem being that Toyota went from a dual sproket driven timing chain to a single sproket timing chain. Note that the tension in the chain is driven by the oil pressure and when the oil is thick it does not correctly adjust the tension causing slack and the chain was slapping around in the housing and eventually wearing into the coolant chamber and eventually dumping coolant into the lubrication passages of the engine causing engine failure. After three trips to the dealer and being told that since I had documented the problem, if the engine ever failed it would be covered. Well low and behold at around 46,000 miles the engine took its proverbial dump. I of course had it towed to the dealer and was told that yes the motor had failed but not for the reason I stated and it would cost me $4000 to have it rebuilt. I of course had it rebuilt as I had intended to keep this vehicle for a long period of time because after all, these trucks were suppossed to last forever. Not to mention I babied the crap out of it and didn't want to go through the whole process again. I went through their arbitration and after a year was told I didn't prove my case even though I had the documentation from the dealer that I had it there three times with the same complaint all arounnd the same time of year when the symptoms would appear. I also noticed in the hottest months I could hear the same noise for a short period of time upon rapid accleration from a dead stop. Once again showing the oil pump was not functioning properly in providing adequate lubrication. After the engine (top end) was rebuilt the engine still makes the same noise and I'm waiting for it to blow up again. I feel sorry for anyone that has had to go through this debacle and I can tell you I will never purchase another Toyota again. Now we have the rust problem which I will soon be taking to the dealer to have the frame inspected. Good luck to you folks and let me know if you hear of any class actions started in regard to this problem and feel free to contact me via my e-mail.

Did'nt your power train warranty cover the engine? I have been hearing knocking for about 15 sec on very cold mornings with the 2.7 liter engine. The engine is very quiet all year till about Nov.

[tinafromthedesert]

I'm also starting to have this strange knocking sound....and it only happens when it's cold..and it only happens for 15-20 seconds.
I took it to a garage and they could'nt find what the problem is. I'm lucky to be working in an automotive store, and one of my co-workers looked up on the internet, some are saying that it could be something to do with carbs building up on my pistons? So I added some seafoam to it...and we'll see what she sounds like tomorrow morning..and so on..I'll let you know.
I know that it only makes a knocking sound for 15 seconds or so, but I still feel a bit concern, she only has about 65000 miles on her.

[bearcat329]

i have the same issue with my '96 Tacoma with the 2.7, however i do have 212k on the clock, and the cold engine knock happens for around 15-45 seconds and goes away, after she starts to warm up, just gonna run it till she blows! no other complaints tho