salimshah

150k+ miles

Salim

Nickv

Salim, Thank you so much for going to all the trouble to document your DIY process. It is such a treasure of help. Terrific job.

av8rga

Thanks to Salimshah for the great thread and information. I couldn't have done it without this.

I completed the repair yesterday on my wife's 2001 RX300. It has 108K miles. All in all took about 7 hours with lunch and I also did the spark plugs, all fluids (trans, oil, coolant), and filters. I did not remove the wiper assy although it would be a big help getting to the hidden upper manifold bolt. I used a offset 10,12, and 14 mm wrench on the hidden bolts it helped big time. Like most work, the right tools are key. Keep a variety of wrenches and sockets, extensions handy. 2 new knock sensors, wiring harness, by pass hose, and 6 plugs $385 shipped from toyotapartszone.com. Gaskets, air filter, PCV valve, cabin filter $150 autopartsexpress.com. Fluids $50 local.

No CEL light now, overdrive functions well, Avg MPG climbing

Thanks again Salimshah

av8rga

Throttle body being removed

av8rga

Throttle body removed

av8rga

Upper manifold removed. The hardest is the hidden 14mm support bolt. I used a 14mm offset closed end wrench turning 1/2 at a time till finger loose.

av8rga

Lower manifold removed. I found it easier to lift out of the way and keep everything connected. I cleaned the injectors also.

av8rga

New knock sensors, wiring harness, and by-pass hose. Like many others I think my sensors were OK and the harness was bad. Testing showed nothing wrong with the old sensors. Also 6 new NGK Iridium plugs.

av8rga

All parts removed and ready for re-assembly.

av8rga

Everything coming back together. Finally done

aktansrt

Great info, and thanks much to you both. I would not have been able to do this without this DIY. Haynes manual is poor at best.

I have recently replaced both on my wife's, and stopped short of replacing the lower manifold/engine block gasket. I do not understand why they had to use a single gasket for the lower intake manifold and the water pump assembly. I realized that I probably have to take of the upper left engine mount bracket to take the gasket off, and decided to go with the original gasket which seemed OK.

Couple of tips that I can think of:

- If you decide to disconnect the "quick connect" fuel line, the top plastic part is a U shaped part, upside down. After taking it out, twist the fuel hose 90 degrees, and despress both ends of the gray plastic clip (quick connect).

- To disconnect the knock sensor wiring harness' back end, first depress the clip to disconnect the two harnesses, then simply tap the knock sensor wiring harness toward the heatshield (cabin).

aktansrt

One more addition to my post above:

- Make sure to maintain the hose and wire routing, i.e. the way hoses and wires/harnesses go over/under others. Before taking the old wiring harness out, you may want to route the new one exactly the same way, and then take the old one out.

Winterdriv

Hello guys,

I am lining myself up to do this repair before the snow falls! Quick question for you. Can you confirm the gasket I need? is it an Intake Manifold Gasket, or an Air plenum gasket set. Or are these the same thing?

Also, when it comes to the gasket, do I need the whole set, or just the upper?

BillJoeBob

Hats off to Salimshah. Great job. Knowing that the bolt head holding the power steering bracket to the back of the intake was 14mm saved me a lot of cussing. Not planning on putting that one back. Whomever was responsible for that design detail needs to be taken out back and given 50 lashes with a wet noodle.

obscene

I thought the same thing, and it worked great for a year or so, until the bracket got so loose that it started to make this awful rattling noise when you climbed the rpm band. Save yourself the time and trouble and do it right the first time.