Mrv8q

Thought I'd update this post. Just did this job on my '99, 195k. It is not a fun job, but doable. Bought 2 Denso KSs, and factory harness. Don't want to do this again. Replaced original bypass hose, 3 back spark plugs, and 3 gaskets.

Only tools I didn't have were a 27mm for the KS, and a 8mm hex for the plenum. The 14mm on the back of the plenum is a bastard to get out, and then in again; there is a power steering hose right there in the way. When you drop the 14mm socket, it will take a while to find...

One KS disintegrated upon removal, and the harness was crunchy from heat. The new harness didn't 'click' all the way upon connection, used a wire tie to snug it up. Lots of broken plastic OEM connectors in the "engine room" now. Trapped heat will eventually kill this car. There was a lot of shredded plastic wire insulation in the manifold valley. Vacuumed all that up and covered injector wiring with new plastic insulator covering I happened to have, 1/2 inch diameter I think...

I have the Chilton/ Haynes manual and the 2001 FSM. Neither one tells the water inlet/dogbone assemble must be moved to allow replacement of the intake manifold gaskets. Those torque bolts were tight, and the gaskets showed corrosion around the water jacket.Also, there are two lengths of bolts securing the intake manifold; I made a note where, in the photo in the Chilton manual showing the order of tightening.

This job took me about 8 hours total, there are many vacuum hoses in this area, so I took pics fo remind me if I got lost.

With the new plugs, car runs better, shifts as it should, and no CEL light after a week. WooHoo, the ES300 lives on... Up next, paying a shop for the timing belt WP replacement. As per Clint Eastwood, I know my limitations.

DRACO A5OG

Congrats, I wil need to swap my KS;s and harness too :-(

BTW, where did you get the Rad By-Pass Hose? Do you have a part number?

LeX2K

This post has a bunch of part numbers including the bypass hose

DRACO A5OG

Sweet, thanks Brother!

DRACO A5OG

Just replaced the Knock Sensor Wire Harness. Yes, it was the Harness

I checked the Sensors and both did not have Continuity, Hewh, saved $250 :-) but had to replace the By-Pass hose and flush all the green radiator fluid out and replaced with Toyota Red.

Drove her for an hour no CEL

DRACO A5OG

Happy to report, Car is in "READINESS" mode, no CEL :-)

dbninc

I know this is very old, but I had a couple questions:
1. Is it necessary to flush the fluid to change the bypass hose, or just in case?
2. Could you explain how I can check my sensors (you called it "continuity")?

Thanks,
Dave

LeX2K

1. Good time to replace the coolant, if you don't you'll lose a fair bit when removing the hose. Some will spill either way
2. Knock sensor cannot be tested with an ohm meter it requires a scan tool or oscilloscope.

dbninc

Thank you, probably better off changing the coolant then. I’m assuming you mean a good scan tool, not my cheap one Haha

dbninc

Started this job today on my 2000 ES300, couple of notes for anyone that does this in the future:

I purchased the majority of my parts from Prestige Lexus of Ramsey, you can order online and the prices are some of the best I've seen. All parts are the most recent version, which means they supersede all previous part numbers. Shipping was very fast. Anything other than the knock sensors and knock sensor harness you can purchase through Advance Auto, make sure you use a coupon. Usually a quick Google search will produce better coupons than the ones they give you direct on their site.

Part : Part Number : Cost
Knock Sensors (OEM Lexus) : 89615-12090 (Need 2) : $201.22/each
Knock Sensor Wire/Harness (OEM Lexus) : 82219-07010 : $37.72
Bypass Hose (OEM Lexus): 16261-20010 : $14.82
Intake Manifold Gasket Set (Felpro - Advance Auto) : MS 92766 : $77.99 (Set did NOT include gasket between Plenum and IACV)
PCV Valve (OEM Lexus) : 12204-20020 : $9.04
PCV Grommet (OEM Lexus) : 90480-18001 : $4.44
Spark Plugs (DENSO Iridium TT - Advance Auto) : IK20TT : $9.19/each
"Pink" Coolant (Toyota/Lexus OEM) : 00272-SLLC2 (Need 2) : $24.99/Gallon

When removing the 14mm bolt connecting the plenum to the hanging bracket, make sure you’re using a quality 6 point socket. I was trying forever with a Chinese Craftsman from a set I was gifted and couldn’t get the bolt. Remembered that I saw a YouTube video once comparing cheap to expensive sockets, and the physical characteristics are different. I have an old USA Craftsman 6 point metric socket set, and the 14 from that set took the bolt off in seconds.

The fuel rails are held in with a bolt on the driver side of the engine. Just follow the gold fuel line to the gold bracket and the bolt will be there. If you don’t know this, you will rip up on the fuel lines too hard and bend them. Unfortunately, I learned this the hard way. The line didn’t bend too far, so hopefully it doesn’t affect anything and I won’t have to replace it, because it looks like a *****. EDIT: Car runs fine, I consider myself lucky. SECOND EDIT: Had to change the fuel injector o-rings on two of the injectors, they were damaged (not sure if during removal or re-installation) and leaking fuel. Inexpensive from advance auto. I would recommend just changing all of the o-rings and lubricating them with petroleum jelly or straight fuel before re-installation, or you’re gonna damage them.

There is 1 ground on the back of the plenum, I dropped the screw and it disappeared somehow. I’ll search for it again tomorrow, but I’m probably just going to buy a new one. I’ll advise bolt size once I get it. EDIT: M6 X 1.00, 10mm (standard size, Tractor Supply had a bag of 4 stainless steel for around $2.00) Take your time and don’t drop bolts or sockets, they won’t fall straight through to the floor, it wastes hours.

To remove the knock sensor wire harness, first disconnect the lower main wiring harness connector. Next, unscrew the nut, which holds the plastic bracket that the wiring harness runs through to the engine. Flip the bracket over so the knock sensor connector pins are facing you. Stick a straight pick into the small opening, and pull the connector up towards you.

I'll update this post once I finish, but those are the big points.

EDIT: Drain most of the fluid from the radiator AND ALSO FROM THE ENGINE!!! There is a drain on the front of the engine near the oil filter, but try to connect a hose to drain this one, otherwise it might end up all over your floor. Ask me how I know. I didn't drain from the underside rear of the engine, got most of the fluid from the first two drains. This is a point of contention, but I refilled with Toyota Pink, even though it previously had Red, since both the parts guy at Toyota and the bottle state they're compatible.