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Knock Sensor Redux Continued

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I finally began surgery on my 94 es300 110k, to get to the knock sensors. Like recent poster, took me 4.5 hrs to get down to them. I found it was easier to remove the egr pipe from the rear of the egr assembly, rather than going under to disconnect it from the manifold.

Both knock sensors were bad! The plastic stalk of the rear one broke as I carefully plied off the connector. The front one looked bad too, w/ the plastic base of the stalk looking deformed (from heat?) and pressed into the metal base. The wiring harness came off intact and continuity was good on both lines. I still plan to replace the harness as I'd already bought one.

Unfortunately the intake bolt nearest to the rear above cyl 5 broke off. This was the only fastener that did break, and I was so happy that none of the plastic connectors were broken in disassembling the intake array! I've been working on that bolt, and finally f-d it up by breaking off an extractor in the hole I drilled (I'm gonna try to return the extractor kit to Harbor Freight, wish me luck...)

This helped me decide about replacing the head gaskets. I'd had 3 overheating episodes since I bought this car in July, and suspected a head gasket breach. Had some milky looking oil on the oil cap which went away after using some $9 copper based stop leak, but I'd been debating doing the head gaskets while I had the intake off. I had definitely planned to replace the thermostat and transfer hose, but the broken bolt in the rear head now necessitates me taking it off and to a machine shop to get it out (unless seomone has an idea how to get it out w/ a busted off extractor down the middle, or if there's someone who's put the intake back w/ one bolt missing. Thought briefly about using a small c clamp but that seems a poor solution (albeit cheaper). I suspect someone had previously been in there and put a mis-sized bolt into the hole, as it looks like it should have been a post w/ a nut as the others further forward on the head.

Looks like I've got more work cut out for me. Supporting my decision to remove the heads are the dark colored spark plugs (not brown/ashy as they should be). Althou this may just be due to running rich in no-knock-sensor-signal default mode, I'd like to take a look at the valves. The plugs were autolite platinums (cheapies) and didn't look old. I bought some ngk irridiums at advance auto for 6.99 a pop.

Bought one new knock sensor off ebay for $55+7, will be looking for another in that price range. Decided to buy a full head gasket set from eristicgaskets($55 I've bought other head gasket sets from them for other vehicles with good results). This set was only a few bucks more than an intake gasket set. Also bought a new pcv valve for a few bucks.

I've reviewed the haynes and now have some questions that folx may be able to answer:

1. I was told by a toyota mech that sometimes its easier to unbolt the rear manifold from the exhaust pipe and then remove it attached to the head as a unit vrs trying to unbolt the manifold from the head before removal. Has anyone had success doing this?

2. Do I need to remove the camshafts before pulling the heads? If the timing belt looks good, can I just slip it off the cams and leave them intact? Or do I need to take off the cams gears/shafts/bearings/lifters to take off the timing belt back housing before I can remove the heads?

3. What's the best way to mark the belt and cams to assure that they are returned without f-ing up the timing? I think I can figure out top dead center for cyl 1, but w/ removing the cams I'm sure the chance of !Removed! up the placement is there.

4. Do I need to take off othe timing belt, with the required removal of the crank pulley, or if the belt is good, can I just let it hang?

5. If I do pull the cam assemblies, should I replace the lifters?

6. So far I've my parts expenditures have approached $200. Trying to keep the cost down, but are there some other things that I should consider replacing while I'm in there?

This has been quite a learning experience for me, first time I've worked on toyota engines or a v6. Not particularly user friendly!

Thanks for any replies.

LL

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Knock Sensor

If you get a code P0330 Knock Sensors ES2000-2001

I just got done replacing two Knock Sensors. it took me 9 hours. I have replaced Parts you are going to need:

1. Knock sensor

2. Knock sensor wiring harness

3. Intake gaskets

4. By-pass hose

5. Antifreeze

Lexus quoted me a price of $224.00 per sensor. (The car has 2 sensors, if you’re going to go through the trouble of changing them, change them both!) RockAuto.com STANDARD MOTOR PRODUCTS Part # KS81 $134 ea

After several hours of bothering the hell out of the parts guy at Lexus he told me that the part number for the knock sensor I needed was 896145-12040.

I ordered the intake gasket kit from rockauto.com for $56.79 this was a FEL-PRO part number MS92766 it came with all 3 gaskets. Also replace PCV STANDARD MOTOR PRODUCTS Part # V313T $3.16 and rubber grommet STANDARD MOTOR PRODUCTS Part # GV21 $2.72

Replaced wiring harness and by-pass hose from Lexus because I didn't have the energy to go through the whole mess again. They charged me $42.00 for the harness and $18.00 for the hose. The Toyota part number for the wiring harness is 82219-07010 and the Toyota part number for the by-pass hose is 16261-20010.

It took me 9 hours to change the knock sensors. It is not an easy job. Drain the coolant first. Then I removed the hood off the car. Then you have to remove the whole top half of the engine.

My best advice for anyone that’s going to tackle this project is to get a small 1/4" ratchet with a swivel head. I used this to get to the intake bracket mount bolts (2), as well as the ground bolt and fuel line bracket bolt that are located behind the intake, there’s not much room back there but this saved me tons of time.

You might as well change the spark plugs cause they are breeze to change with half the engine missing.

Fuel injector rail stays with the intake manifold not to be separated.

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Lexlogic,

I read your "reply" on previous post yesterday or the day before. No need to repeat yourself. But do let me know if you have any thoughts about the questions related to taking the heads off.

LL

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whth the same knock sensor problems, I disassembled my 1999 rx300 as per the advice of contributors and the large shop manual for a 2002'. After closer inspection, I simply can't see or find the knock sensors. Is it remotely possible that mine doesn't have knock sensors?

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Nobu,

Not sure about '99. What engine is in your rx300? Look at the front bank timing belt cover where the numbers usually are. In the 1mzfe and earlier, two ks located under the intake manifold in the "valley" between the two banks (cyl heads). Ks bolt into the block just below the heads on either side. Note the intake manifold is is different than the plenum which attaches to the top of the intake).

LL

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Seems that I have't finished disasssembly. I haven't removed the intake manifold which would account for not being able to view the knock sensors.

I'll keep posting my progression.

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Nobu,

Not sure about '99. What engine is in your rx300? Look at the front bank timing belt cover where the numbers usually are. In the 1mzfe and earlier, two ks located under the intake manifold in the "valley" between the two banks (cyl heads). Ks bolt into the block just below the heads on either side. Note the intake manifold is is different than the plenum which attaches to the top of the intake).

LL

Well, finally was able to find the knock sensor(s). Did the appropriate diagnostic tests only to find that they were both ok. which wasn't good news because that meant I had look further, I tested the EFI relay to be bad so I ordered that.

While I'm waiting for all the parts, I finished disassembing in preparation for the timing belt and all the other drive belts.

One question I have for you or anyone who would know: If you rotate a pulley for either cam 180 deg. from intake tdc, does that take you to exhaust tdc? and how do you tell if you are at tdc intake in the first place? Thanks in advance

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Pull #1 spark plug and insert long screwdriver or something similar and feel for the piston to rise as you rotate the crank. If the piston starts to drop then turn the crank back. Thats just about TDC

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Sometimes the wiring harness to the knock sensors is bad...gets really hot on top of the engine.

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