A Few Tips Regarding Rear Valve Cover Gasket Avalon

[smata67]

Just finished this job up. Rear valve cover was leaking quite a bit, causing odors in cabin and quarter sized drops of oil in the driveway. Firstly, and I can't imagine why it did not occur to me to do this first, the bolts for the cover should be checked and tightened. This may very well be enough to solve the problem. Mine were quite loose when I got to them. This alone may have stopped the leak. By the way, if one of the intake mounting brackets in the rear is in the way of one of these bolts, simply unbolt and move to the side, as they rotate. I would stuff some newspaper down there to prevent bolts from slipping out of your hand and disappearing. Two bolts are used for the brackets, 10mm-1.25 20mm and 12mm-1.25 20mm. The 1.25 size is not easy to find.

Anyway, job is done. I would advise getting the following, in addition to all of your tools, before starting: replacement gasket (I used Fel Pro VS50471 R, very nice and comes with plug seals), 10mm and 12mm gear wrenches (for tight spaces behind engine), coolant, RTV (a dab is required in several places before putting the cover back on, see the Haynes), plugs, wires, throttle body cleaner (it will be very accessible when disassembled), water bypass hose. Underneath the throttle body is a clamped hose that brings coolant to it, predrain the coolant a bit or this will leak throughout the job, I lost all the coolant from the reservoir through this hose. And don't forget to reconnect it before bolting the throttle body back, as it will be inaccessible. There are a number of bolts holding down the rear wiring harness, pretty much all need to be found and come off, just keep looking for them. I flipped the wiring harness over the chrome egr connection tube so as to get the valve cover off. I chose to not replace the plug seals, they were in pretty good and I did not want to risk damaging the cover.

There is a photo tutorial that covers many, but not all, of the steps required for the job. I had all the photos printed out in color and used them for reference and was very helpful. All in all, the job was not easy and I would not recommend it for a beginner diyer, took all day. Car runs very smooth now, though, plugs had 140K and throttle body needed cleaning, I'm sure.