2.7L engine knock

As for altering the ignition timing for vehicles where timing is controlled by the ECU, you have to access the control chip then reprogram the timing.

 

my truck does the same thing.you need an oil filter that prevents all the oil from going back to your pan,and keeps it on the top of the motor.it worked for mine.

 

I've been giving this "knock" problem some considerable thought and I may have a possible answer. On the newer engines, the engine timing is totally controlled by the Engine Control Unit. The ECU makes decisions based on info provided by sensors located on the motor and in the intake and exhaust stream. Therefore it makes sense that if one of these sensors is not working properly, then the ECU would make a "wrong" adjustment. In this case, it seems reasonable to check the "Knock Sensor" first. I have no idea in hell how to check it or even where it is located, but it sure seems to make sense. Anyone ever replaced their Knock Sensor"?

Some Knock Sensor reading: http://www.asashop.org/autoinc/july/techtips.htm

Reading the above and some info on Yotatech, it seems the Knock Sensors only rarely fail, but the wire between the knock sensor and the wiring harness connection can and does fail due to excessive heat exposure. Most recommendations are to replace the wire first to see if this eliminates the problem, allowing a good clear signal from the knock sensor to the ECU.

 

I had the same problem with my 2.7 using 10-30 only knocked on initial startup,questioned mechanic and was told heaters could help but the oil could be too 'thick' to flow till it warms. I added a pint of marvel oil and have been listening but not hearing the knock. My 2.7 is also a 160k+ motor, lots a life left! Hope this helps!

 

My 01 knocks when cold. It has almost 160k on it but it burns no oil. Tried different oil's synthetic and regular oil no change. The last time I tried 0w-30 it made no difference but cost me extra money. I give up but still sounds like oil starvation to me.

 

It takes about 2 min of cold idle time with my truck,,then there is no knock. If I do have to take off quickily for whatever reason, (EX: late for work, ect) once I hear it just start to knock, I back out of the throttle and just move along with very little load on the motor and no knock. a mile or so down the road and the knock is gone (Pistons have expanded a bit, clearance is tighter).

Optimally, you should wait until the motor is at complete operating temp, before taking off, and usually I do that. About 5-7 minutes or so. IMO.

I am sure this has been debated on here a few times and I will probably be dog piled on, but, a higher mileage motor needs a thicker oil than factory recommendations. Once those clearances increase from mileage, you loose less and less of a oil wedge between parts when running.

To that end, I use Shell Rotella triple guard 15W-40, and have been since it hit about 120K miles. Let the dog pile begin!!!!

 

alot of people don't understand with engines you have to start the motor and do not touch gas pedal,you can hear when oil is at the top of the motor.its called dry starts and almost every car does it.i live in miami and still let my motor run at least a minute before driving.i have 125.000miles and my 2.7 still runs like the day i bought it.i use castro gtx 5w30.with a little motor honey mixed in.

 

My '07 with 45K does this. I think it's perfectly normal and understand the concept, but it is definitely more noticeable on this motor in cold weather. Also seems to last a lot longer than on my Jeep or Honda. So I can see where the original poster was concerned - have to admit I was too!

 

lol I have the same basic problems as the op. Engine knock on start up *more so when I put it in gear* and a sticky accelerator. It's nice to know it's nothing serious though.

 

Cheapest cure - switch to synthetic. My 2.7 had a tic at 30F and below. I used a oil pan heater last year and that worked with dino. This year I'm using syn and have not heard the tic and we have been down to 17F in the AM. I haven't had to use the block heater at all - maybe I should just for an easier warm up but I don't need it for the tic.

 

It could be your piston rod hitting the side due to lack of oil or if you take it to a shop they can put bushings inbetween the piston rod and the head gasket to keep it from hitting

 

What the H.? ? That truck is still practically new. Modern FI engines only need a short period of fast idle (30 sec) before they can be driven away, gently. That's under normal circumstances of course.

If a connecting rod is hitting the head gasket, that's an entirely different problem...

 

this more of a cold weather thing.i live in miami,fl and the only time my 99 with a 125.000 knocks is in cold weather.below 40degrees,if thats even cold to you guys.everytime i change the oil 3500 i put just a couple of onces of motorclean.i just had the valve gaskets replaced and the topend was spotless.one of the cleanest toyotas motors i have ever seen.not one drop of deposits or dried oil.

 

Originally Posted by RedYoter10
My 2010 will do it when its cold, I just let it warm up until it comes off the cold mark

he'll be sorry when after a few years he has a years worth of unnecessary idling on his motor which does more harm than good

 

i'am telling everyone that you can hear when oil gets to the top of your motor.i suggest not touching the gas pedal until its up top.dry starts.and its a cold weather thing.over 125.000miles and no knocking in my motor.and runs as good today as in 99.the only knock is below 35 degrees.

 

all this talk has got me super nervous. im a highschooler who saved and saved for the 96 i just bought last week. i had the toyo dealer and another mechanic listen to the motor and they both said it seemed alright but neither drove it. its been cold here (-5 to 20 F) since i bought it and my truck does the same thing you all describe. upon startup and below 1000 rpm's its fairly noticeable and decreases in volume after a few minutes of warming up. as soon as i depress the gas pedal it either goes away or is too quiet for me to hear. as soon as a let off and come to a stop sign or something, it begins again quietly. any thoughts? i know its been covered but i really need some reassurance. oil was changed to 5w30 today.

 

If the 5W30 is syn that will help. A oil pan heater will help on a 2.7 4cyl. I use it under 30F. If you have a 6 cyl you can get a block heater that plugs in to a factory made hole in the block - real easy.

 

its conventional. i would say the ticking has decreased in volume after the oil change, and it has warmed up outside considerably in the last 24 hours or so. once i drive for a few minutes, the ticking is very minimal if even noticeable. are these all good signs that its nothing to worry about?

 

Probably but I just don't like the ticking that's why I use syn oil and oil pan heater under 30F over night = no ticking.

 

Can a Engine block heater be retrofitted?

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