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Before I changed the fuel pump it failed to start on me even after it was warmed up.
I've made an appointment for walnut blasting with a shop. ($630 CDN) The knocking is still on and off. Perhaps cleaning the carbon will help or maybe they can inspect it further while they have everything apart.
In the mean time I'm trying to run a fuel system cleaner or injector cleaner every couple tanks to see if it makes a difference.
I don't think I've noticed any longer cranks recently.
The car is at 173K Miles now. It starts, drives and performs well but just has the annoying intermittent knock.
So I've now gotten the walnut blasting done. It may have been good for the car but it did not help with the knocking issue. So this further leads me to believe its a fuel issue rather than a carbon build up issue.
I've noticed the knocking occurs mostly when braking or if the car is on a decline. So perhaps it has something to do with the fuel in the tank. When the car is braking all the fuel is probably rushing to the front of the tank.
I'm going to try to keep the tank over 3/4 and see if it makes a difference.
The car starts and drives fine. I'm just trying to pinpoint the knocking issue because I don't think it can be healthy long term. Its also a bit embarrassing.
It is so hard to diagnose something from just an audio file so please understand this post to be merely speculation and nothing more than an effort to help in your search.
From what I could hear with headphones on it did not sound like an engine knock or anything metallic to me. It seemed to be more of a buzzing like a shield, or plastic item that was buzzing. Then when you said it happened on deceleration and perhaps turns I thought of a time when my friend's inner fender came loose and would rub on the tire under certain conditions. That was pretty easy to find as it was a Lexus RX and I could just duck my head under the wheel well and look for a rub spot. One of the plastic clips had either failed from a road debris impact or it was left off from a shop visit. Anyway, it is worth a try to look for something like that that may be buzzing at a frequency that is commensurate with throttle input and/or driving conditions. Splash shields beneath the car, missing clips on harnesses under the hood, a plastic tie wrap that someone used on a stereo install, those sorts of things. Remove your under hood plastic covers and see if you can pinpoint anything under there. At the auto parts stores you can get a cheap stethoscope for a few dollars with a long probe that will take you well within the engine compartment, I use them to listen to water pump bearings and the like. They are quite handy. Again, I am just guessing here, and the sound is quite muffled from inside the car, so perhaps you can get in a quiet area like a parking garage and have a friend modulate the throttle while you inspect further from the outside to pinpoint the sound.
Good luck, and I'm glad that the walnut shells remedied the hard/no start for you.
So I've been driving the car since the last update with no issues other than the intermittent knocking sound. It even started today in -6F (-21C) without issues.
I've noticed this under the hood for a while and I just thought I'd share it to see if anyone thinks if it could be related. There's some oil residue on the rubber hose going from the intake pipe to the engine block and also some more oil residue what I believe is a timing solenoid.
The stock intake has a little box which I guess is suppose to catch the oil vapor but the JoeZ intake does not have this.
Does anybody know which solenoid this actually is ? There's a bunch when I look at the parts catalog on rockauto.
Did you change the pump or someone else? If the mesh screen was loaded with debris, fuel cleaners won't remove chunks pumped into your tank from a fill up. If there is any doubt about debris being in the tank I would recheck that and confirm it has not repeated itself. In addition the pumps construction has tight enough tolerances that fine debris will wear it and reduces the fuel pressure available for starting and the mechanical high pressure pump.
Keep in mind that during the start sequence, the tank pump is being used with an injector in the intake manifold to spray fuel to aid cold start. Low fuel could definitely be the cause of your starting issues way back when and impact it now if the pumps pickup is occluded by debris and/or worn as mentioned before.
I didn't listen to the engine knock sound but if there is any doubt about it being a rod bearing knock, fit an oil pressure gauge to it and check the oil pressure when hot.
Mechanical gauges with copper pipe and a few fittings are cheap and you'll know more about your engines health. It only takes 5 to 7 psi to keep the oil pressure sensor happy and the light off. This is not enough at higher rpm to keep the engine alive. Tho one poster said it didn't sound like a rod knock / this is good!
I changed the pump myself. The tank looked to be very clean surprisingly. I changed the entire fuel pump assembly not just the pump, so everything on the tank side is new.
Not having any starting issues anymore. It's just the knocking sound sometimes. Could it be because the camshaft solenoid covered in oil isn't functioning correctly and causing the noise?
So I've been driving the car since the last update with no issues other than the intermittent knocking sound. It even started today in -6F (-21C) without issues.
I've noticed this under the hood for a while and I just thought I'd share it to see if anyone thinks if it could be related. There's some oil residue on the rubber hose going from the intake pipe to the engine block and also some more oil residue what I believe is a timing solenoid.
The stock intake has a little box which I guess is suppose to catch the oil vapor but the JoeZ intake does not have this.
Does anybody know which solenoid this actually is ? There's a bunch when I look at the parts catalog on rockauto.
It's a side branch resonator. Google it for Helmholtz resonator.
As far as I know the 250 AWD does not like anything besides the stock intake set up. Meaning complete air box with stock filter etc etc. I've pretty much tried them all. Nothing compares to the stock set up. With aftermarket intake pipes the car feels so bogged down. As soon as you put the stock back in the car comes alive again.
If you had a bad OCV the cel light would trigger, and have a rough idle.
Im sure if you had knocking wouldn't the knock sensors detect? On my old GS400 they would pretty much imobilize the car. I had to keep my scanner hooked up, and erase the cell just to get home one time. One knock sensors was out.
Just as an update. The car has 188K on it now. The knocking noise is intermittent and I have not been able to narrow it down to what causes it exactly. I can go a week or more without hearing it and then randomly it will make noise again.
Overall though I would say switching over to high mileage synthetic oil and a bunch of fuel systems cleaners has reduced the frequency of the noise. I cannot decide if its a fuel issue or a bad lifter. No loss of power or performance. I guess I will keep driving it as is until anything changes.
I've been trying to monitor it and narrow it down if its happens more when its
warm or cold
full tank vs low tank
high speed vs low speed
But I have not been able to find any consistency. The only thing that is consistent is that when the the noise does appear its usually when decelerating towards a stop.
Maybe a product of when it's running rough/not smooth?
Perhaps open the hood, E- brake on, place a solid foot on the foot brake, engine on, trans in drive and apply some throttle and see if you hear the noise and if the engine jumps around. Repeat in reverse. Notice anything alarming? They do move and that's OK to a point.
I use Shell 91 V-Power almost exclusively. I had to use a no name station once when I ran out of gas. The dash still showed about 24 miles to go but the car stalled out. I filled up with premium but it was a smaller independent station. Would 1 fill up at a bad station be all it takes?
Otherwise I always use Shell unless I'm out of town on a road trip and there's no Shell on the route.
Did you find a solution yet? My 2012 IS250 started sounding like this
Hi, I took my 2012 IS250 to a muffler shop and 3 auto repair shops. The muffler shop and 2 auto repair shops said I don't have an exhaust leak. But one shop said there's a leak in the exhaust manifold gasket and it's a super small leak. The 2 shops that said there's no leak couldn't tell what's going on with that noise. I don't know what to do.
Hi, I took my 2012 IS250 to a muffler shop and 3 auto repair shops. The muffler shop and 2 auto repair shops said I don't have an exhaust leak. But one shop said there's a leak in the exhaust manifold gasket and it's a super small leak. The 2 shops that said there's no leak couldn't tell what's going on with that noise. I don't know what to do.
Could it be carbon build up? read this link, and follow the test procedure mentioned.
If you getva cell then you'll know it's the build up.
I took it to a muffler shop and they found out that the fuel lines are vibrating. I took it to another auto shop which confirmed that the fuel pump is failing and it's vibrating a lot which is also the source of the vibration. Replacing the pump fixed the noise for me. The pump was under warranty since it was replaced under a year ago. My vehicle is super smooth now.
08-24-18, 08:29 AM
