2002 Toyota Tacoma 4 cyl engine knocking

[jackneysneeb]

2003 Tacoma 4cyl Reg Cab Automatic 17,000mi.
Hi
New to the site. I just wanted to document my info on this forum
Intermittent knocking in/around engine.
Also have the "clunk" - when switching into park, reverse
etc. Like the knocking, the "clunk" comes and goes under unknown circumstances.

Oh yeah, I paid cash and they didn't even give me floormats. >{
Going to take to dealer soon. Will update.

[silvertaco4x4]

i have a 2000 tacoma 2.7L with just over 100k now and ive got the same noise. so far it only happens during the winter, usually only at first start-up in the morning. it is a deep sounding, low hollow knock and doesn't really last too long (although longer this past winter than the winter before) but it drives me crazy and it really does sound bad. two dealerships have diagnosed the sound as "normal", one of the two said it is piston slap. seeing as its summer now i dont have to deal with it, but man would it great to not have to hear it when the weather starts getting cold again. please post again if you find a solution to this problem. take care all.

[Brian R.]

Try using a block heater in the winter.

[silvertaco4x4]

thanks for the suggestion, i had actually been considering that. but, i must have jinxed myself with that last post because this morning, the truck was knocking despite warmer weather. disheartening to say the least...not sure if its the same knock or different one now. this morning it almost sounded lighter and lower down on passenger side. it only ever happens if i actually drive off before the truck warms up, and doesnt really last long enough to do a decent job of trying to locate it.

[weedgar]

G'day, Over here in australia we have the 2.7 engine in our hilux range
of trucks, mine is a dual cab 2wd and my friend at work has a single cab,
both are 1998 models, mine is auto and his is a manual, mine has done 160000 km his 56000 km. these hilux's are built in japan,and they are the top selling trucks in australia. we both have the same knocking noise.
the low milage truck knocks on cold start almost every morning and if left
for 4 hour+,the high milage truck knocks some mornings only, the noise is the same in both. it lasts around 10 seconds and is loud enough to hear with windows up and radio on.it is a real metal to metal knock. i am a mechanic and it has me stumped, one theroy i have is that the main timing chain tensioner creeps back when the engine has stoped (it has a ratchet pawl to prevent this)and on startup the tensioner arm is slapping back on the tensioner,after a few seconds the oil pressure pushes the tensioner back out and the noise goes away. the toyota service manual says to check the operation of the ratchet pawl at overhaul. if i pull my tensioner out i will post again to let you know.seems to me toyota's are knocking all over the world.

[slipshod]

My 2003 Tacoma 2.7 made a loud knocking sound on a cold start-up.My dealer said carbon on pistons,decarboned the head and the noise went away.

[Zepcrmc]

I have a 2001 2.7 Tacoma 4x4 and it also started knocking just a few days ago. I have 98K miles on it. Mine knocks after it warms up, about 15 min. and stays kncocking.

I am taking it to my mechanic this morning hopefuly it is just a valve adjustment issue. Does anyone know how often you are suppose to get the valves adjusted. I have done virtually nothing to the truck in 5 years other than oil, brakes and tires.

Some of these posts are a bit disturbing and I do not know how long the Powertrain warrenty is on my truck, I think it was at 100k but I am fast approaching this mark and if that is the issue than I want to start the issue with Toyota today before I go over that mark

[Zepcrmc]

My mechanic looked at it yesterday and determined it was not the valves and that it was the oil pickup screen that was clogged and causing the knock. The bad news is he found what appears to be pieces of my timming chain tentioner. Once he puts the oil pan back on and the front trans he is going to pull the timming chain cover and check that out. I will keep posting until it's fix

[Flash75]

"My mechanic looked at it yesterday and determined it was not the valves and that it was the oil pickup screen that was clogged and causing the knock. The bad news is he found what appears to be pieces of my timming chain tentioner."

I think your mechanic should at least look at the rod bearings before installing the oil pan, I'm very surprised he/she didn't suggest that. If the clogged oil pickup is really the problem and the engine was run with the knock there is some bearing and perhaps some crankshaft damage. To me this would be a bigger problem than the assumed timing chain tensioner parts. I Wonder how he determined the screen was clogged enough to cause a knock? A defective timing chain tensioner could also cause an engine knock. Sounds like your mechanic isn't sure what is causing the knock.

If he blames it on the oil screen clogging, they are probably going to say your oil hasn't been changed as the maintenance schedule prescribes. Do a Google search on "Toyota engine sludge" and see what comes up.

I'm not saying the tensioner parts should be ignored, that should be corrected, but not before making sure the main and rod bearings and their associated crankshaft journals aren't damaged from lack of oil due to the clogged oil pickup screen.

Clifton

[Flash75]

This link has lots of Toyota engine sludge information.
http://www.google.com/search?hl=en&q...=Google+Search

Clifton

[Zepcrmc]

Originally Posted by Flash75

"My mechanic looked at it yesterday and determined it was not the valves and that it was the oil pickup screen that was clogged and causing the knock. The bad news is he found what appears to be pieces of my timming chain tentioner."

I think your mechanic should at least look at the rod bearings before installing the oil pan, I'm very surprised he/she didn't suggest that. If the clogged oil pickup is really the problem and the engine was run with the knock there is some bearing and perhaps some crankshaft damage. To me this would be a bigger problem than the assumed timing chain tensioner parts. I Wonder how he determined the screen was clogged enough to cause a knock? A defective timing chain tensioner could also cause an engine knock. Sounds like your mechanic isn't sure what is causing the knock.

If he blames it on the oil screen clogging, they are probably going to say your oil hasn't been changed as the maintenance schedule prescribes. Do a Google search on "Toyota engine sludge" and see what comes up.

I'm not saying the tensioner parts should be ignored, that should be corrected, but not before making sure the main and rod bearings and their associated crankshaft journals aren't damaged from lack of oil due to the clogged oil pickup screen.

Clifton

He orginal, before taking anything apart, thought my valves needed adjusted but after 2 hours of research he was leaning more towards the Oil pickup screen. He said the screen was clogged with small pieces of metal from what ever he found in the oil tank. This is not a dealer, it's a mechanic I have used for 15 years and I trust his work and know he will not overlook anything nor will he rip me off. He only charged me $350.00 to pull the oil pan and replace the pickup screen, By the book this is a 6 hour job. The dealer wanted $650 just to pull the oil pan and inspect everthing, no replacement parts just looking. I trust his judgment and I am sure he will look at everthing before it puts it back together. He builds race engines for cars, boats and motorcycles and has been doing this kind of work for 35 years

[Flash75]

It does help that you have prior experience with the mechanic and trust him. Please let us know what really corrects the problem.

Clifton

[Zepcrmc]

Originally Posted by Flash75

It does help that you have prior experience with the mechanic and trust him. Please let us know what really corrects the problem.

Clifton

It looks like I need a new engine. My mechanic found that the metal was from one of the harmonic balancers. the passangers side will sway side to side about 3/4". This is rediculous to have to replace the engine after only 98k miles on it. $5k later and a new engine hopefully I will be on the road by next week.

[Flash75]

That is depressing, I was hoping it would be something simple. Thanks for keeping us posted.

Clifton

[sunbugone]

I too have a similar problem. I purchased an 01' tacoma on the used lot with 58,000mi, about two years ago. I hardly ever drive it (I commute on a motorcycle) I now have just over 64k miles on it. I am an ASE certified and Rolls Royce master technician. I have taken good care of the truck. My knocking is getting worst every time I drive it. It closely resembles a diesel. I have determined that it is piston slap. It occurs on a warm engine, at idle. It is fine all other times other than the driveline vibration(different story) This is most likely the cold start noise most of you are having. The piston takes time to swell into the cylinder. Mine on the other hand has prematurely worn out. I have an appointment scheduled with toyota on Wed, I have a bad feeling my "extended warranty" will fight me until I fix the problem myself. I was able to get a new transmission last year when a main bearing crapped out. I am not happy, my 91' 22RE was far superior to this truck. I had 193,000 on it when it was sold. I'll keep you all posted. Justin