clintbw

I bought my 2001 ES knowing it had a few issues. The main issues were the two knock sensors; I had codes P0325 and P0330. Since I was going to take everything apart anyway, I decided to change the gaskets of everything I removed while I was at it, as well as a coolant drain and fill (duh)... I don't have the knock sensors or the harness in the mail yet (they're supposed to be here Saturday) but I went ahead and resealed the coolant plate underneath the intake and ordered a new bypass hose (also should be here Saturday)...

My question for everyone here: is there anything else I should look at or do while I have everything apart? I'm hoping replaced the KS and KS harness will fix the codes I had. I also had code P0306 and the engine seemed to run poorly, so either the KS errors are causing it or I need new spark plugs or coils.. I'm going to wait until I have everything together to make sure it wasn't the KSs...

With the knock sensor codes, my car was immediately put into "limp" mode and the car had little power, shifted roughly, and wouldn't go into O/D... I have yet to drive this car without any CEL so hopefully Saturday will be my first day.

clintbw

Update:

I installed the knock sensors and knock sensor harness, no more error codes from them! I also resealed the coolant valley underneath the bypass hose, and replaced the hose.

Now onto the next project... figuring out my misfire issues.

tomf

Nice. After I got my 99 ES, I had to replace the knock sensors and the O2/AF sensors. These are common maintenance items.

hypermikem

I am currently getting ready to do this on my 2000 Avalon(similar to ES300). I am thinking my coolant leak is coming from either the bypass hose or the valley underneath it. So how was it?
Was it as much a pain in the rear as it seems? I assume you used FPIG or similar to reseal the valley plate below? Any tips you can offer to make this go as smooth as possible? WOuld be much appreciated. I too have a slight misfire as well. Very little leaking when car is normal operating temp, but leaks from that area first thing when I start it until it reaches normal temp. The misfire and the noticeable leak started at about the same time. No OBDII codes either, so needless to say I'm going to change the spark plugs and rear coil packs just because they will be accessible, however if it was a coil pack I would think a code would register, no? Anyway, this is a big job and a bit intimidating, so I was just wondering if it was as bad as it looks. It has to be done, but I can't afford to take it to a stealership.

clintbw

I completely understand you not wanting to go to the dealership. They quoted me $1600 to replace the knock sensors/harness and to reseal the valley plate. The job was honestly not as difficult as I had anticipated, granted I have changed the valve cover gaskets on my old V6 Camry so I was somewhat familiar with taking off the intake assemblies.

Before I began the work, I purchased a new OEM bypass hose and a new OEM knock sensor harness from concordlexus on eBay, and bought used OEM knock sensors from a private seller on eBay. It all cost me about $90 or so for parts.

Take the entire intake assembly out (intake box, throttle body, EGR, intake plenum, and lower intake manifold) and be sure to label your vacuum connections, hoses, etc... This is also a good time to clean out the intake plenum, throttle body, IAR, MAF, etc. with appropriate cleaning solutions (auto parts store)... Once I got to the knock sensors, I removed the harness... the connections to each knock sensor were so brittle from excessive heat/coolant that they crumbled with my touch. I used a large wrench instead of a 27mm socket to remove each knock sensor.

Once here, be sure to clean out the valley under the intake manifold. Mine had residual coolant and lots of debris (leaves, dirt, and old plastic particles from wire looms). I was pretty liberal with the sealant (I just used the Black Silicone RTV from the auto parts store), let it sit overnight, then applied another layer the next day (maybe overkill)...

Make sure you place the bypass hose on completely. Mine was extremely tight but I managed to get the rubber all the way over the connections and secured them tightly with clamps (the clamps were there from an earlier aftermarket job/aftermarket hose... which makes me wonder who the heck had my car previously to do such shoddy work...). I also replaced the intake gaskets and tightened everything to the appropriate torque spec evenly (nobody needs vacuum leaks...)

Good luck to you. After I had reassembled everything, I was stabbed in the heart with a misfire code on a few cylinders and had the random misfire code (P0300)... Turned out I had not secured the two bolts above the throttle body and had a vacuum leak. Fixed that, and had only the P0306 code (misfire on cylinder six). It took me much longer than needed (still fairly bad at troubleshooting properly) to realize my ignition coil on six wasn't working. I took off the connector to cylinder six -- no change in engine smoothness... took out cylinder five coil connector and noticeable difference. Voila! My problem was ignition coil six. So I replaced it and my car runs perfectly now, despite a damaged front catalytic converter (error code P0420) from what I assume would be the misfires (which the misfire may have honestly been there before but unnoticed because car was in limp mode since I purchased it a few weeks ago due to the bad knock sensors)...

Long story short, for having this car for only three weeks, I've learned more about this engine than I had planned to, haha. So far I've changed knock sensors, harness, air filter with OEM Lexus filter, hood struts, map light assembly, bought OEM floor mats, replaced all front headlights (low beam/high beam-DRL), fender wells*, oil pan*, driver CV axle*, and installed white LED tag lights. *ordered and waiting to receive to install/have installed

hypermikem

Well the work was done. The leak as expected turned out to be the bypass hose. Had a tear near the clamp. Also replaced all the plugs and rear 3 coil packs. The middle one was damaged on the end. Sort of broken off due to brittleness. Work went smoothly as I expected or hoped that is. I printed out torque specs and sequences for him to use. Took right around 4 hours. Took a few beer breaks too. No leaks detected as of yet and the misfire is gone so far as well. Smooth acceleration like before. We did find one broken vacuum line however that was not previously known. It is a nipple sticking out of the Vapor Canister Purge Solenoid - Toyota part# 25860-62010. The broken nipple was still stuck in the end of the hose. It definitely was sucking air.

I hooked up my new Blue Tooth OBD2 scanner for use with Android and it sure worked nicely. Pulled up 3 codes for me. How nice. Lol. They were codes P1135, P1155, and code P0773. So I reset the codes and let it run for a few miles. Came on again. So I took it back to my mechanic and told him what I found, and he said well let's take a quick look. About 2 minutes later I heard a strange chuckle. He said I forgot to hook this ground up. There was a ground wire that hooks up to the back of the plenum. Hooked it back and reset the codes. Ran it about 25 miles, still no CEL, or pending codes. So far so good. Still am running with one of the vcv hoses plugged with a screw but still no cel anyway( new VCV ordered). One little ground wire can really cause a lot of havoc! I'll run it for a few days before I declare her good to go.

I hope this is it for a while. These cars are nice, but they do need to be taken care of. I was wondering for while if I didn't find myself with a lemon, but in hindsight these were relatively minor issues that I inherited because of maybe the previous owner not changing fluids and other consumables as often as I am going to, and plus the Dealer mechanic re-using a rubber hose(bypass) after changing out knock sensors and harness. That was truly a boneheaded move IMO that was destined to end badly. Good thing I addressed it at the first sign of leakage on the ground. Could have been worse if it had full on ruptured while I was on my trip to LA. So now I have fresh oil and filter, fresh tranny fluid and filter, new plugs, new air filter, new coil packs(back 3 for now, one was broken), new cabin filter, some new resonator hoses and new coolant, as well as new intake gaskets. All in the span of 3 weeks. So I would think that should hold me for a bit. I hope!

PFB

Only other thing that I can think of in terms of maintenance, is the PCV valve.

Excellent work

Phil

hypermikem

Yes the PCV was changed when I changed the spark plugs the first time. Forgot to add that, sorry. That is so easy to change, and I have read some bad stories about them becoming brittle and breaking off into the engine, so I plan to change those out every 3-4 oil changes. They are cheap and easy enough to swap. Still going good. Fingers crossed. Next on the list is some new struts, but no big hurry for those. Still got time to shop around for a good deal.

yeskay

can you provide the part number for the knock senor and knock sensor harness. mine is 99 es

Bumbobee

I'm about to do a knock sensor job myself, except that I have aftermarket sensors and harness. Going to replace the gaskets and valve cover gasket too. I hope it works, as I've been told Aftermarket sensors don't work well sometimes. Not doing the job myself, looks complicated.

Bumbobee

Anyone have a page from the service manual or another guide on step by step how to do the knock sensors?

Going add the hose into that replacement as well...

PFB

Changing the bypass hose at the same time is a smart move.

Bumbobee

Does the coolant need to be drained before replacing the knock sensors? Or can I just drain what's in the tubes?

Also does the large coolant hose on top from the radiator needs to be disconnected for the job or can I leave it on?

fredalert2

Does anyone know why knock sensor prices are so different from Autoparts store VS online.

2001 ES300 3.0 V6

tomf

convenience