Last post on Nov 09, 2013 at 5:09 AM
You are in the Toyota Camry
What is this discussion about?
Toyota Camry, Sedan
#5197 of 5646 Re: Knock Sensor [beantown]
Aug 29, 2010 (5:03 pm)
There is only one wire that carries the signal from the knock sensor to the car's computer. This is the only wire that could have been affected by a rodent. It is NOT necessary to remove the intake manifold in order to test this wire. It can be checked by disconnecting the computer's wiring harness plug, along with the wiring harness plug to the knock sensor; and then using a meter to measure the resistance between that wire and ground; together with the resistance between that wire and the battery. If the knock sensor is totally inaccessible without removing the manifold because of its location; the test can be performed by just disconnecting the harness plug at the computer, locating the knock sensor wire in that plug (which is listed by its color in the service manual) and then testing the wire for either shorts or grounds while the knock sensor is still connected to the other end. This may or may not be the standard procedure recommended in the service manual for testing this problem; but it will work. However; it will require a technician who understands electronics; rather than a flunkie who only knows how to do what the manual says. If the dealership refuses to do this simple and inexpensive test; they are either trying to conceal their ignorance, or they are determined to rip you off. Try another dealership; or take the car to a competent auto electrical, fuel injection and computer specialist and pay them to test the wire. It should cost much, much less than $500. There is a significant chance that the problem is caused by an internal fault in the computer; rather than a chewed up wire. Remanufactured computers for older Toyotas can be purchased for less than $400 from places like www.rockauto.com. But they don't list computers for 2004 and newer Camrys. You could also order a used computer from a 4 cylinder 2007 Camry by phoning a wrecking yard that has a nationwide parts locating hotline. After a request is placed on the hotline; any yard in the US that subscribes to that hotline and has this part will contact your local yard and arrange to ship the computer to them. If you want to see how much you'd save by going this route; phone your local Toyota dealer's parts department and ask them the price for a computer for your car.
#5198 of 5646 Re: Knock Sensor [zaken1]
Aug 30, 2010 (6:54 am)
Thanks for the responses. Just to clarify, they were able to run the test and confirm the bad wire for free. What they couldn't do for free is confirm WHY the wire went bad. In other words, they could access whatever they needed to access to run the test itself, but couldn't confirm why it went bad and supposedly can't actually replace the bad wire without removing the manifold first.
I'm still weighing my options on this one. It's driveable for now, so I'm not forced to decide one way or the other.....and I need the car (don't feel like paying for a rental while dealership after dealership look at it). I just have a feeling that no matter which dealership I go to, they're gonna give me the same "not covered under warranty" angle.....even if it is 100% the car. I mean, really, unless I'm standing next to them when they open it all up, how else could I ever prove that something wasn't nesting in there? They can essentially say whatever they want.
#5199 of 5646 Re: Knock Sensor [beantown]
Aug 30, 2010 (7:15 am)
Ask to be there when they take it apart. Call Toyota and open a case.
#5200 of 5646 Re: Knock Sensor [beantown]
Aug 30, 2010 (12:24 pm)
#5201 of 5646 2007 camry rattles and water pump
Sep 05, 2010 (4:54 am)
Has anyone had any problems with the water pump? Dealer has told me I need to have my water pump replaced, seems like I should not have this problem so soon.
I also noticed that when I step on the gas the car makes rattling or knocking noise.... what could this be?
#5202 of 5646 Re: 2007 camry rattles and water pump [mssweet]
Sep 05, 2010 (5:06 am)
I have a 2007 LE and when I accelerate I do hear what I think may be valve clicking. When my air condition is running (and I live in the New Orleans area) I am hearing a strange clicking/swooshing noise. Conversely, turning the a/c off will eliminate this particular noise, but the acceleration clicking remains constant.
I actually had a rat eat thru my firewall when the car had only 7K miles on it. I nearly traded the car in then. The recall happened after that point.....water under the bridge. Well, I now have 35K on it.
#5203 of 5646 Re: 2007 camry rattles and water pump [hislamb]
Sep 05, 2010 (5:18 am)
Well you'll need someone to look at it, and determine what the cause of the problem may be.
For the engine clicking, what I normally do is to remove the accessory belt, and then start the engine briefly. If the clicking continues, then you know the problem is internal to the engine. If the clicking stops, then the problem is with one of the accessories driven by the accessory belt. I typically find problems external to the engine, as opposed to internal. With the engine off, and belt off, you can then turn the accessories by hand, and feel whether the bearings are good or not (looking for wobble, free and smooth, etc). Replace what is bad.
For the air conditioner 'swooshing', I assume that is a noise you hear inside the passenger compartment. That may be low water levels in the radiator/heater, or low freon levels in the A/C system. Or, it could be a number of other things. It's much easier for someone to diagnose something when they hear the sound themselves, as opposed to your interpretation of a sound, relayed across written words to the internet.
So get someone to look at it, and see what their diagnosis is.
#5204 of 5646 Re: 2007 camry rattles and water pump [mssweet]
Sep 05, 2010 (10:40 am)
It would be helpful to know why the dealer said the water pump needs replacement. If it was because the bearings were loose; a replacement definitely would be necessary. But if the dealer said there are signs of "weeping" coolant around the pump drain hole; this possibly could continue at about the same level for a long time to come, without it getting severe enough to do anything about. It also depends on the quantity of coolant that is being lost: If the coolant level is dropping rapidly enough that it is necessary to add coolant once or more every month; this should be attended to. But if there is little or no indication that the coolant level is dropping significantly, then coolant stains near the water pump area are strictly a cosmetic issue.
Many people confuse a sound that they think is valve noise with the pinging that is created by use of low octane fuel. The way to distinguish those two types of noise, which both sound similar; is to notice when and under what conditions the sound is loudest. Valve train clicking is usually loudest when the motor is idling; and does not become louder when stepping on the gas. It often can also be heard while the car is slowing down. Valve train clicking is often caused by not changing the oil often enough, or by using an unsuitable oil type, or by mixing or changing brands or types of oil. Contrary to popular myth; the additives in many oil types will react chemically with each other, which can lead to shortened engine life and possible engine damage if one brand and viscosity of oil is not used consistently.
By contrast, pinging usually cannot be heard at all when the motor idles or is slowing down; and becomes louder as you press the accelerator pedal further. Pinging can be caused either by low fuel quality; or can also be caused by excessive engine temperature, or low engine oil level. Please be aware that some types of coolant leaks can cause the coolant level in the radiator to drop; while the level in the plastic reservoir bottle may look good. So it is ESSENTIAL to check the level directly in the radiator (by removing the radiator cap while the engine is cool) whenever the engine begins to run above the normal temperature, or pings. The radiator should be filled to the very top of the filler neck. When adding coolant, be sure to mix the pure coolant from the bottle with equal quantities of distilled water, before pouring it into the cooling system. Adding water to coolant is necessary in order for the coolant to transfer heat efficiently. Using 100% pure coolant will make the engine run hot.
There is also a third type of similar noise, called piston slap, which is loudest when the motor has not warmed up to normal operating temperature, and often goes away or is greatly reduced after the motor warms up fully. Piston slap is loudest when driving at a steady speed or accelerating slightly. It usually cannot be heard when the car is slowing down. Piston slap in Toyotas is often heard when using very light viscosity energy conserving motor oil (typically 5W-20 or 5W-30). These oil grades were mandated by the US government, because they theoretically increase fuel economy (by less than 1 mile per gallon). But the legislators who pushed that law through were not aware of the fact that some engine designs (namely Mazda rotarys and Toyota) experience adverse wear and noise when using such lightweight oil. New car dealerships in the US who install anything but energy conserving oils are liable to be legally prosecuted; but this law does not apply to independent garages or people who change their own oil. The best oil for reducing piston slap is Mobil 1 full synthetic (but only in 0W-40 grade). 0W-40 is a European oil formula; which was developed for Porsche and Mercedes. Any store that sells Mobil 1 oil can order it in 0W-40, if they don't already carry that viscosity.
#5205 of 5646 Re: 2007 camry rattles and water pump [zaken1]
Sep 05, 2010 (1:01 pm)
An excellent, informative post. Thank you, zaken1.
#5206 of 5646 Re: 2007 camry rattles and water pump [mssweet]
Sep 05, 2010 (4:09 pm)
I haven't had any problems with my 2007 Camry's water pump. How many miles do you have on your car? I experienced a knocking from the engine (V-6) once but the dealer told me it's from a bad batch of gasoline (watered down). It never happened again after that. I use mid-grade 89 octane or once in a while high test 92 octance.