My 2008 Toyota Camry Hybrid is making a Spark Knock, Acceleration or Transmission noise between 20-35MPH, any ideas?

2 Toyota dealers says it is happening too inconsistently to figure out the cause or it doesn't act up enough for them to determine the cause of the issue. Happens when ICE is engaged and is making a diesel type sound when Accelerating. Check out the two youtube videos I linked below
http://www.youtube.com/watch?v=IcBosxBvvSc
http://www.youtube.com/watch?v=0frv80g-jqE

Thanks for anyone else who might be able to chime in on what this noise is. It doesn't always make this noise. Sorry about the background helecopter noise on the second video, but it was acting up quite well in that clip.

 

Mine does it too. I know the sound. It sounds horrible and is really loud outside the car. I can hear is best while driving along streets with curbs or in parking garages. I have always run decent gas and have done regular Techron applications. Mine got so bad that I had to switch to 93 octane fuel. Even 91 octane will not cure it. But, with 93 octane the noise is gone.

My first though was a bad knock sensor. I have yet to have mine checked since switching to the higher octane fuel solved the problem. Please let me know what you find out (if anything).


Edit: Forgot to mention. Mine does not do it when cold and it was sporadic. It would not do it all the time. Mostly when the car was completely warmed up and during slow ICE accelerations as you mentioned. As an example... Turning off of a 45 MPH street directly onto a 35 MPH street without stopping and then accelerating up to 35 MPH gradually is when the noise was the worst.

 

Thanks Lightspeed for the info. Thats very helpful as it seemed to go away after I had the premium fuel in it after doing the fuel treatment and injector flush thru toyota. I'll have to follow up and PM you if toyota ever figures out whats wrong with mine that it does this. It did initially sound like spark knock to me when I first heard it, but wasn't sure if it was something else as it is very loud outside the car but harder to hear with the windows up.

Hopefully some others can chime in that either they have the same issue or better yet what the fix is for this issue.

Thanks all!

 

I had my windows cracked on my '07 TCH one night going up a overpass to town. I was traveling at only 35 mph as their was no other traffic late that night. My wife said she could hear the engine making a knocking and rattling sound evidently reflected from the concrete protection wall.

I could not understand this as I was using Texaco regular, which is a toptier gasoline. I asked the local toyota tech about this as I know him from the other two Toyotas I bought there. He said, the Texaco station evidently got a bad batch of gas. A month later I filled at the same Texaco again once I ran the tank down rather low. After that I was glad to find it ran just fine.

I have mentioned here before that the top tier gasolines have a Techron type additive in each gallon. Chevron used Techron as their addative. Other top-tier brands have a similar additive but with a different name.

I bought some discount no-name gas for a Ford 500 I had bought in 2006. The car was hard to start, poor acceleration with some rattle in the engine. I lost gas mileage trying to save some money of the gas purchase. It took some techron and Lucas gas additive and 3 tanks of then Chevron gasoline to get the car to run back to normal. I learned my lesson on saving 4 cents per gallon of gas.

Find a toptier gas station. Try to find one that a block to 4 blocks from some discount low priced station. You will find the major brand will try to stay close to the discount station to keep his business busy.

This is the list, click the link Retailers also try the other links to read why top tier is better.

www.toptiergas.com/

 

Switched back to 87 Oct. for giggles. No detonation on the first tank. Halfway through the second tank it started again. Now worse than before. Now, cruising at 55 to 60 MPH and lightly accelerating I can hear the same noise I am hearing at 35 MPH. Still does it at slower speeds too.

Does not matter where the gas comes from. I have tried them all. Techron does nothing for it. I bet I have put 30 bottles of Techron through this car in the past 9 months. All at high concentrations.

Still the only thing that fixes it is 93 Oct. fuel. So, I guess I am stuck using the expensive stuff for now.

I plan to have the dealer change the inverter coolant hear over the next couple weeks. I will have them pull the codes and see if they can duplicate it.

 

Sounds like a slight detonation problem. I had a Olds Cutlass in the old days that pinged when you accelerated the slightest around 50 mph. This was back when the no-lead gasolines were leaving deposits on top the low compression pistons. I had to use a major brand of gasoline and a gas additive for 3 tanks to get rid of the problem.

I would suggest running your tank down to near empty, then add 5 ounces of techron or a few ounces of Lucas which is cheaper, then fill up with a top tier gas. Like with the Olds I had, it took 3 tanks of a good (same) brand of gas to clean those deposits out.

Could be you may have a stubborn single injector that will in time clean itself. Another is to find a grade like going up a moderate steep overpass. Half way up if you can slow to about 35 mph, then floor the accelerator if it's safe to do so, allow the rpm to build up over 5 or so seconds. Sometimes doing this will allow enough fuel though the injector to clean itself out.

Keep a eye on your temp gauge. Normal temperature in the few toyotas I have owned, read 40% scale after the engine has warmed up.

About the pink inverter/radiator coolant. A toyota tech says, it should last 100,000 miles then change it out ever 50,000 miles after that.

 

Typically, ignition is retarded to stop a knock. I wonder if the knocked sensor is not functioning or the ignition module is not retarding timing if it is instructed to by the ECU.

 

These are my initial thoughts as well. I have had 2 vebicles in the recent past that have had knock sensor issues. They are fairly easy to test if you lnow where they are.

I'm pretty sure this is the issue.

 

Yeah, I have the very same issue with my 2007 TCH -- knocks like an old Cutlass. I have used top tier gas faithfully also. Toyota really is starting to irritate me with this stuff. I have an old GM minivan with over 150k miles and the engine runs great. But my TCH knocks at 85,000 miles even though I have maintained it well. Makes me seriously wonder about buying Toyota/Lexus again. Now I am forced to either put up with the occasional knocking, spend more on premium gas, or feel like the owner of a jalopy and have to buy gas additives at Wal-Mart. I really don't want to sell it but may have to, especially if I start having hybrid system issues after 100,000 miles. I really thought a Toyota was a long term purchase but maybe I was wrong.

 

It's guesswork on my part, but could it possibly be the (4) iridium spark plugs. I forget how long they are suppose to last in the '07 TCH maintenance manual.