DGIKULJOT

Hey guys,
I own a 98 lexus es300 with a leaking rear valve cover gasket, the car has 163k miles on it and is still going pretty strong. I want to try and tackle this job myself.
I am an electronics engineering student, and I am pretty handy with tools.

I bought a pdf sevice manual for my car on ebay for like 6 dollars and it has nothing in their abou replacing valve cover gaskets. So I was wondering if you guys can give me any tips or pointers. Also from some of the other posts I read there are some diagrams out their which show where we have to put some special sealer on the valve cover? can someone please shed some light on this for me.

I would greatly appreciate if someone can link any documents relating to this job as I dont think it would be worth it for me to buy a Haines manual just for this job.

Thanks

Hayk

iTrader: (1)

I'll update this post later today. I did the job last summer with almost the exact same mileage on my car.

BDSL

Off the top of my head
- remove the top engine plastic cover
- remove the air intake plumbing
- remove the intake manifold, EGR, etc
- remove the spark plug wires
- at this point, you should have access to the rear valve cover. Remove it!!
- replace the valve cover gasket and the 3 o-gaskets inside the valve cover
- apply some RTV sealant on the valve cover gasket where there is sharp turn/corner
- put everything back in.
- do not over torque the valve cover bolts!!!!!

Hayk

iTrader: (1)

In addition to that, here is your suggested shopping list:

Intake Plenum Gasket
16 new Valve Cover Bolts (they come with new crush washers)
Valve Cover Gaskets and Spark Plug Tube Grommets
RTV for the gaskets
Central Coolant Hose (runs underneath the intake manifold)
Mass Air Flow sensor cleaner
Carb Cleaner for your Idle Air Control Valve and Throttle Body

Optional:
Red Toyota Coolant (2 gallons of unmixed)
Top and Bottom Radiator Hoses
Spark Plug Wires + Spark Plugs
Positive Crankcase Ventilation (PCV) Valve
Air Filter

Some reference sites:
http://www.toyotanation.com/forum/10...ent-1mzfe.html
http://www.wjowsa.com/carstuff/toyot...lve-cover-job/
http://www.bonnieandjason.com/2008/0...t-replacement/

Be prepared to curse the people who put this engine together.

tomf

You can do it. I just got done replacing my rear valve cover twice.

Tip number one. Make sure the gasket is in place before you torque the bolts. The first time, when I was putting on the valve cover the gasket slipped out of its slot and did not seal the cover. On my ES the engine wiring harness blocks easy installation and prevents easy visual access to determine it the gasket is in place. Because I could not see, to ensure that the gasket remained in place, I felt with my fingers to determine it the gasket remained in its slot. From personal experience, if the gasket is not in place, oil will flow out onto the exhaust system. There will be smoke everywhere and pond of oil under your car.

Tip number two. If, when installing the valve cover, the valve cover does not seem to slip into place, make sure the spark plug tubes go through the spark plugs seals in the cover.

Tip number three. For me, the most difficult task was removing and replacing a manifold stay bolt, near the firewall and toward the front of the engine. It's a 14mm bolt. There is a metal line (power steering?) of some sort that is bolted to the stay. The line blocks access to the bolt. The stay is "u" shaped which also blocks easy access to the bolt.
----- I ended up unbolting the line from the stay. I used a socket to remove the bolt partway. The firewall and the line prevented me from using the socket to remove the bolt completely. Then I used a flex head ratcheting wrench to remove the bolt the rest of the way. Of course I dropped the bolt twice which required removal of the wheel to retrieve the bolt.

Tip number four. Make sure the throttle body stay is in place prior to torquing the manifold down. There is stay that connects to the throttle body, toward the rear of the engine. Twice I installed the manifold and throttle body. When I went to bolt the throttle body to this stay I find the stay is jammed under the throttle body. Hence I have to remove the manifold ( and deal with the manifold stay bolt again) to rotate the stay into position.

Tip number five. Label all connections with masking tape and felt tip marker to aid you when putting everything back together.

Tip number six. Replace your spark plugs because you have to remove them anyway.

Those are the things that stand out from my recent experience. That said, I can say I'm getting pretty good changing the valve cover gaskets.

DGIKULJOT

I would like to thank everyone for all the tips and links. I will tackle this job when I have two days off in a row just in case . One problem I did have when trying to clean my throttle body is the secctio of the air intake tube is stuck onto the thottle body assembly and I am trying not to use too much force so it doesnt break or crack, and yes I already have the bolt loosened, but it seems as if that tube glued itself onto the throttle body. What would be the best way to loosen it up, would wd 40 be safe to spray on the rubber?

Also for the rtv sealant , does the selant go between the gasket and the engine block or between the gasket and the actual valve cover?

That intake gasket is pretty pricey, around 50 dollars!!!

Finally is the Haynes manual pretty useful for this car. Later on I will have to replace cv axles and stuff so I am trying to decide if that manual will be helpful.
Once again thanks for the replys and if anyone has any other tricks/ tips I would definetly appreciate them.

Hayk

iTrader: (1)

It depends on your experience. I have gotten away with using forum DIY guides and youtube, along with a factory service manual. I can send you the PDF, if you'd like.

Hayk

iTrader: (1)

As for the intake hose, spray it down with some WD40 and wiggle.

DGIKULJOT

Yes I would greatly appreciate that, My email address is
kuljot123@att.net

Thanks for all the help

Hayk

iTrader: (1)

PM sent

The RTV goes between the gasket and the cylinder head. You will find some residue from the factory, once you're there.

Sewell Lexus is a great source for factory parts. I recommend them for the PCV valve, coolant hoses, gaskets, and bolts. All the other stuff is cheaper elsewhere.
http://lexus.sewellparts.com/parts-c...S300-1998.html

Make sure you register on their site as a ClubLexus member and login, before shopping for parts. They give us a pretty hefty discount. The Intake Plenum(17176-62030) gasket is $11.84 (MSRP), and it's $7.16 through Sewell. You must have been looking at some other gasket, possibly the Intake Manifold gaskets (the ones between the cylinder heads and the intake manifold)

EDIT: I forgot to mention that you need two special tools for this job. First is a Torx E6 socket for the wiring harness above the front valve cover. Second is a 5/16" (I believe it's 8mm) Allen key/external socket for the Intake Plenum.

brucelee1

iTrader: (2)

If it is not leaking too bad, you might try one of these oil additives for older engines. Sometimes, they actually work!

Hayk

iTrader: (1)

Those stop-leaks do more harm than good. Replace the gasket and be done with it.

mitmaks

I recommend rockauto.com for parts. Ive saved a bunch of money going through them.

NCTQ

I have a 1996 Lexus ES300 and want to buy the OEM Lexus parts for the Valve Cover Gaskets and extra parts that MrBooby recommended (spark plug wires, intake plenum, bolts, etc) . Do I have to buy the Engine Overhaul Kit? or do they sell the parts individually? In the Lexus dealers like Sewell searches for valve cover gasket don't bring anything up. I don't know what I'm doing but I've found a good mechanic (who doesn't speak much english) that can do the work if I bring the parts.

NCTQ

I didn't know how to look for these things on the Sewell Lexus site so I copied this list in an email to them and they kindly put together a Cart for me. They noted that for my 1996 ES300 "For the spark plug wires, be mindful, you ES uses coil packs. While these can be readily replaced, they are usually done so on a repair basis only (not for maintenance purposes)." And they were very expensive.

Is this correct?