1998-2000 Valve Cover Gasket Replacement

[richardkwon]

Guys, I'm in the middle of my timing belt replacement and with everything removed, I can really see that my driver side valve cover gasket has been leaking for a long time. I've got oily soot and dirt running down everything. It's never been a heavy leak, but more like a seepage and explains why the oil level would never stay full. I've got the engine compartment practically all torn down so now it's one of those if you're there you might as well do it type of deals for me.

So my question is there any tutorial (besides the one on lexls.com) on the 1998-2000?

Looks to me like all that has to be done on the driver side valve cover is remove the ignition coils, some wires and hoses and pull off the cover? The manual indicates that the oil and automatic transmission dipsticks must first be removed? It looks like there is some space to wriggle off the valve covers without having to first remove the 2 dipstick housings, which I understand is a nightmare to remove do to the tight space and the fact that the bolt is hidden.

The passenger side looks a little easier.

Also, the half moons in the back toward the firewall, should they be replaced also? Does not look too hard to do from what the manual describes.

Does the throttle body and intake manifold have to come off also?

I've read about all the difficulty in this job so I'm starting to wonder if I'm missing something. Any help or tips would be appreciated.

[landar]

Oddly enough, I have never seen a tutorial on the 98-00 models. And you are right in thinking that while you have things torn down this far, why not? The leak could be as simple as loose valve cover bolts but it would be nice to have new gaskets in there when the job is complete. I would put new plugs in while at it as well.

I do not believe that you will have to remove the throttle body(it faces outward from the front of the motor) nor the 'intake manifold' (although I really think you meant to say 'intake plenum'). It looks like you will need to remove the Coil on plug modules x8 and various vacuum and control hoses/lines (mark with masking tape and indicator to reconnect).

The drivers side may be the hardest one with the oil and tranny dipstick brackets in the way. I have taken the tranny dipstick out before and it is a royal pain(sorry to her 'Highness', Steve). You have to feel for the bolt (8mm, IIRC). I really think you can just loosen the bolts slightly and gently bend the tubes slightly out of the way, putting them back after the valve cover is wriggled back in.

The good news is that you have the perfect opportunity to author a new tutorial on how its done on a 98-00! Lucky you. ;)

[richardkwon]

Oddly enough, I have never seen a tutorial on the 98-00 models. And you are right in thinking that while you have things torn down this far, why not? The leak could be as simple as loose valve cover bolts but it would be nice to have new gaskets in there when the job is complete. I would put new plugs in while at it as well.

I do not believe that you will have to remove the throttle body(it faces outward from the front of the motor) nor the 'intake manifold' (although I really think you meant to say 'intake plenum'). It looks like you will need to remove the Coil on plug modules x8 and various vacuum and control hoses/lines (mark with masking tape and indicator to reconnect).

The drivers side may be the hardest one with the oil and tranny dipstick brackets in the way. I have taken the tranny dipstick out before and it is a royal pain(sorry to her 'Highness', Steve). You have to feel for the bolt (8mm, IIRC). I really think you can just loosen the bolts slightly and gently bend the tubes slightly out of the way, putting them back after the valve cover is wriggled back in.

The good news is that you have the perfect opportunity to author a new tutorial on how its done on a 98-00! Lucky you. ;)

I took another careful look at the driver side and it looks like the dipsticks would be in the way because one has to lift the cover off of the spark plug tubes and to do so would require that finicky transmission bolt to become undone. How did you get that bolt back on?

And as for a tutorial that's not a bad idea.

[landar]

How do you get the tranny bolt back in? Just by feel. You can use a mirror to get your bearings but it is mostly by trial and error feel. If you do not actually move the tranny tube too much, it should not be a huge issue but plan on a few cuss words getting that bolt back in.

[richardkwon]

Well, the guru Landar has convinced me to do a tutorial and so here goes. The car is a 1998 LS400 with 118,000 miles on the clock. The valve covers have never been off the car. I only removed the right hand (passenger side) valve cover today so that's as far as I will go. As I complete each stage of the VC gasket replacement, I will update the tutorial accordingly. It will probably take me a week or two. I've searched far and wide for a tutorial for the 1998-2000 but can't find one anywhere.

I noticed about a year ago that the RH VC was leaking in the middle and oil was seeping down ever so slightly onto the exhaust. I tightened up the 2 middle bolts and so far have not noticed any more leaking. Like everyone says, the bolts are torqued very lightly at the factory and after time, they become very very loose, so much that you can remove or tighten some of them with your hands. Not all the bolts are this loose, but feel them and you will know. For those of you who don't have the time, inclination or determination to replace your VC gaskets, I think the retightening idea is a very good one as it worked very well for me. But for me personally, I just have to make things right and new again. I can't leave well enough alone. So here goes.

RH Passenger Side VC Removal

I'm in the process of replacing my timing belt so everything is off the car already. I'm going to skip all the details of what major items to remove in detail but you will have to remove the V-Bank Cover, the Air Cleaner Inlet and remove the PS air hoses, PCV hose, and the EVAP hose at a minimum. The service manual also states to remove the 2 right and left timing belt covers. Not sure if this is totally necessary but mine are already off. And if anything looks to be in the way, by all means, remove it.

1. The first thing I did was to disconnect the black connectors that connect the engine wiring harness (runs along the fuel rail and is protected with green plastic insulation) to the ignition coils. Just press down on the small clamp and pull the connectors off the coil. I've heard other folks say this before, but those clips are brittle as hell due to time and heat and 3 or maybe all 4 of them will break off. If this is the case, don't be alarmed, just slide the broken piece out. The rear clip was the only one that survived. I'll just tape the connector and coil together at reassembly. I'm sure as hell not going to buy a new frickin' engine wiring harness. The second picture shows a broken one.

2. Using a 10mm socket, undo the 4 ignition coil bolts (one for each coil). Then slide/pop the coils off the spark plugs. They should come off fairly easily. I set them aside and as each coil is the same, it really won't matter if you switch them around at reassembly but I kept them in order just the same. New coils cost about $150 each at the dealer in case you are wondering. That's $1200 for the set. Holy cow. I'll reuse mine thank you until I absolutely have to change them.

3. Using a 10mm socket, undo the bolt near the firewall holding the engine wiring harness.

4. Using a 10mm socket and various swivels, extensions, etc., remove the 9 and let me repeat 9 VC bolts. I mistakenly missed the one right near the PS pump and kept wondering why in the hell the VC would not come off. Again, count that you have removed 9 bolts. There are 4 on the top, 4 on the bottom, and one to the right just left of the timing belt cover near the RH cam. Use whatever angle and contortionist abilities you have to remove the bolts. Take your time, and you will get them all undone. I had to get in front of the car, use my left hand, my right hand, etc to remove the various bolts by hand. The bolt on the left rear top is partially hidden under the wiring harness. Lift up the wiring harness with your left hand and use a 10mm socket on this one. FYI, I did not have to use a tedious wrench for any of the bolts. A socket wrench is all you will need. All the bolts have rubber washers on them. Some will be oily and some will not. Bag them. Now it's time to remove the VC.

5. Remove the power steering air hose that goes from the PS pump to the top of the intake manifold. It is a very long hose and does get in the way when removing the VC from the right side. My hose cracked when I removed it so I will be replacing with a new one.

6. The engine wiring harness (the long wiring that is encased in green plastic is attached to the intake manifold by 10mm bolts. Remove the 2 bolts in the middle. This will give you some slack in the harness to give you more room. The black circular plastic covers may break and again, there's not much you can do. Either jimmy it up at reassembly with tape or buy new replacements. The reason to loosen the harness is to give you some more room to lift up the VC. Unplug the connectors on the top right side of the VC. This includes the ECT sensor and the OVC (Oil Valve Control) sensor. To break the VC gasket seal, I carefully placed a large flat tipped screwdriver right where the upper top right corner of the VC is (nearest the ECT sensor). Carefully wriggle the VC out. The left side will hit the AC hoses and other things but just be patient. I wriggled the right side out first by carefully sliding the wiring to the right. Just take your time and never force anything. Eventually it will come off. I fought with it a little but in the end I won.

[richardkwon]

I removed the LH VC today. More details and secret removal tips to come.

But first, let me celebrate and enjoy a nice cold beer or two.

Attached are pics of the RH camshafts and you can see where the oil was leaking in the middle and dripping down on to the heat shield.

As for the half moons, they looked fine and are actually made of aluminum. No need to replace unless they are leaking and I think they can make it to 200K easily.

[richardkwon]

LH Driver Side VC Removal

1. Like the passenger side, first remove the 4 black clip connectors from the 4 ignition coils. Guess what? Like last time, 3 out of 4 of the tabs broke. Rather than break the last one near the firewall, I just pulled the ignition coil off of the spark plug and laid it on top of the manifold.

2. Remove the 4 ignition coil bolts using a 10mm socket. Remove the 4 ignition coils by popping them off of the spark plugs and set aside.

3. Undo the 2 vacuum hoses (1. EVAP hose from the charcoal canister from the VSV for EVAP and 2. EVAP hose from charcoal canister from the EVAP pipe on the intake manifold) from the manifold that run from the driver side fender to the intake manifold and then undo the bracket holding these two hoses with a 10mm socket. Move the 2 hoses back toward the fender. Using a zip tie or string, attach the hoses somewhere away from the VC.

4. Undo the large PCV vacuum hose that sits on top of the left side of the VC and goes to the front top of the intake manifold opening. Leave the hose on the VC and just remove from the intake manifold. After the VC is out, this will be a great time to remove and replace the PCV valve, grommet, hose and cover and not have to worry about shattered plastic falling onto your camshafts.

5. Unclip the black fuse box cover adjacent to the fender and take off the fuse box cover. Undo the 10mm nut that holds the fuse holder and the wiring harness. No need to take them off the stud. This is just to give you additional wriggle room when removing the VC.

6. For additional wriggle room, using a 10mm socket undo the 2 black bolts holding the black plastic piece that covers the engine wiring harness where the OBDII reader is. Again, there is no need to remove this piece. It’s only to give you more slack and wriggle room.

7. Using a 10mm socket, extension, swivel, etc. remove the 9 VC bolts. The 4 that run along the top and the one on the side near the LH Cam gear were easy to remove. The 3 trickiest bolts for me were the 3 that run along the bottom nearest the firewall. The bolt adjacent to the firewall is easily removed by using a 12 inch extension and placing it underneath the fuel hose with your hand underneath the brake fluid reservoir (see pic). The remaining 2 bolts in the middle require some finagling but are not too difficult. You won't cuss too much at this stage. It's actually a fun challenge finding the right socket combination and angles to get these bolts off. Like the passenger side, there is no need for an open ended wrench tied to a string per the lexls.com tutorial. All you need is a socket wrench, short and long extension and a swivel. Again, just be patient, use your best contortionist skills, and when the bolts are loose, undo the rest by hand as it is much easier and faster that way. For some reason, the second bolt from the firewall was on very tight and even after getting it ¾ of the way out, it was still difficult to turn. And believe it or not, I missed the 9^th bolt again! I was never good at math.

8. Remove the oil dipstick and the automatic transmission dipstick.

So the rest should be easy as pie, right? Nah, that would be too easy. There is no way Toyota would let you get off that easily. The service manual says to remove both the oil and automatic transmission dipstick tubes. Wow, that’s going to be a lot of fun. I located the transmission tube bolt and tried to simulate inserting the bolt with my right hand and found out it’s almost impossible to get my right hand to turn the bolt. Looks like I would need to place the bolt in a socket with a short extension, then cuss to high heaven and pray that someday I'll get the bolt aligned just right with the thread hole.

Well, guess what? There is no need to do any of this nonsense!

9. DO NOT REMOVE THE OIL TUBE AND AUTOMATIC TRANSMISSION TUBE (unless you love punishment. And believe me, I love punishment as much as the next guy, but this would be ridiculous!)

10. Remove the oil cap. This will give you some much needed clearance when the VC is slid under the wiring. You can also use the oil fill tube to place your left hand in for leverage later on.

You are now done with disassembly and ready for the actual VC removal!

11. First, take the big flat tip screwdriver or pry bar and carefully and gently pry it into the upper left corner of the VC right around where the bolt goes. This will break the seal. Then go to the top right corner and using the screwdriver gently lift up the right corner. The angle is not good and there is nothing solid for the screwdriver to rest against except wiring and the fuel hose so be careful. Just a slight lift up will do. Then alternate lifting the left side with your left hand in the oil cap hole and the bottom left corner, gently lift the VC from the top part towards the fender so that the spark plug tubes clear the VC. Be careful of the engine wiring harness, especially the top left wires as they will get caught on the corner. The upper part of the VC should about 45 degrees or so higher to the bottom to gain clearance from the pesky oil and transmission tubes. Also, the left side of the VC should be more higher off the cylinder head than the right side during removal. Keep sliding the VC up and to the left at the same time and keep looking for wires and hoses that may snag. Then slide the VC to the left and out. Just go slowly and make sure no wires are getting caught on the VC. Be patient and it will come out. Don’t worry about the oil and transmission tubes moving a little. There is some slack with the tubes and that's a good thing.

So that’s pretty much it. I kept worrying about having to remove those two hidden oil and transmission tube bolts. And actually, with the VC off, those two bolts are now very easy to access and remove.

So if you've ever wanted to change out your transmission filter, now's a perfect time to do it. For me, I'll just wait until the 200K mark. I'm sure the filter is still clean.

I did notice that the VC has much more gunk under the VC than the passenger side. I’m thinking this is due to the PCV being located here and all the blow by.

Inevitably, there will be dirt and plastic bits and FPIG that falls into the camshafts. Make sure you remove all debris.

Sorry the pictures are so crappy. I'll try to post some better ones later.

[richardkwon]

Attached are some pics of the LH VC. Notice all the gunk, carbon and caked on oil that has hardened into a nice crust. Took me a couple of hours to scrap it all off using a gasket scraper, small flat tipped screwdriver and whatever else that works. I don't think it's really worth the time to scrape this junk off but I like my stuff to be clean. Be careful when scraping the inside edges where the flat plate meets the sides of the VC. The metal board actually covers a cardboard like material underneath and about a 1/4 mm extends out and you can gouge it/rip it.

The passenger side VC was surprisingly very clean and had some cake right where the PCV hose area is.

Also attached is a pic of the RH torn PCV hose. It's hard as a rock and with the crack, not doing it's job. I had a number of hoses that were hard and cracked and that probably explains my recent imperfect idle as of late. If you don't want to shell out the money for an OEM hose, you can use a 90 degree fuel hose and cut to fit.

My spark plugs were all dry and there was no oil leakage. However, I noticed on one spark plug tube seal that oil had made it past the seal and probably in another 5K to 10K miles would have started to leak into the spark plug hole. My recommendation: always replace the spark plug tube seals! It is not that difficult of a job but it is tedious as hell. I messed up on 3 non OEM seals until I finally got the hang of it. And now I could do these in my sleep.

[landar]

Excellent write-up and pics, Richard. Thank you!

You have earned your beers!

[richardkwon]

Now that the VC is removed, make sure everything is clean. First remove the gasket. Mine was not rock hard or brittle, but it was fairly hard and not soft and pliant like the new gasket. I used brake cleaner all throughout. Make sure the valley where the gasket goes is nice and clean. Remove any original FIPG with a razor blade. The FIPG will be around the half moons and the 2 corner spots where the cam housing is.

Now you can remove and replace the spark plug tube seals. To remove, there are 4 claws that surround and go over the edge of each tube seal. Take a small screw driver and bend these up as much as you can up to 90 degrees. I first bent them up and then used some pliers to complete the 90 degrees. Then take a nice big flat tipped screwdriver and wedge the tip under the seal and pry up. It will be awkward and difficult at first but after the first couple, it becomes very easy. Wriggle it around and soon they will pop out. The rubber on mine was hard and brittle. Basically, the seal has a metal skeleton and does not flex. The inner part that fits over the tubes are flexible. Be careful not to gouge the VC metal.

I had ordered some Beck/Arnley seals and although they are made in Japan, there is a clear difference from OEM. I decided to go with OEM as it is a better design. The OEM seals come pre oiled so no need to apply MP grease on the inner lip. The pic of the OEM is on the right. The ingenious part about these seals is that it has a secondary pooling area to catch oil before it can drip into the spark plug tube. Basically, if the seal fails and oil gets beyond the seal, then before it can drip into the seal, there is some space for oil to pool. You will have to see the actual seal to see what I mean. It's hard to explain in words.

Then, clean the tube seal housing of all oil and debris using brake cleaner.

To install the seal, I found it easiest by first taking the seal and pressing down with both thumbs. Make note of which side is up with your old seals as a reference. Let one side go in a little further at first. Then, using a hammer, just pound the seals in but be careful not to hit the claws and try not to damage the rubber. After the seals are in, tap the claws back into their original positions with a hammer.

Or if you don't feel comfortable with the hammer approach, you can go to Harbor Freight and buy their Transmission Stop Off tool for $6. It fits the diameter of the seal perfectly.

The fourth pics with the old seal bent is not the correct way to remove the seal and you will end up scratching up the walls of the housing. In the beginning, I wedged a screwdriver on the outer part of the seal. Don't do this. It is much easier prying from the inner part. Instead, with the inside of the VC facing you, take a large screwdriver and place underneath the seal. Then pry upwards. Or you can do it with the outside of the VC facing you, take a screwdriver and using a hammer pound it down and out. Again just be careful not to gouge the metal.

[richardkwon]

To remove the spark plugs, all you need is a 16mm spark plug socket and a 6" extension. Take the spark plug completely off the threads and then to remove, use a rubber hose to pull it out. No need for pliers. This method works far better than the little rubber crap that is in the spark plug sockets. Those things are always popping out due to oil and never work for me.

To install the spark plug, use the same rubber hose to start the thread. Don't overtighten the plugs. You will feel the washers beginning to crush, then do another turn or 2 and that will be enough. The service manual calls for 13ft/lbs for those wanting to torque correctly.

Don't forget to gap the plugs to .43"

[richardkwon]

Now is also the perfect time to replace your Oil Control Valves. They are located right above each cam gear. Cost about $90 each and the left and right sides are different in that the connectors are in different locations.

There are also Oil Control Valve filters for each valve, but to replace these $6 filters, the bearing cap will need to be removed. It's just too much work and if you regularly change your oil and PCV valve, you should be fine. Again, like the half moons, you may want to reseal the bearing caps at 250K or so.

First unplug the black connector.

Using a 10mm socket, remove the bolt.

To remove the valve from the housing, I used a big screwdriver and using a hammer and gently punched it out. Have a rag underneath as there will be some oil spilling from the valve. Be careful of the wiring that will be in the way of the connector, especially on the driver side.

Notice that the new part has a different (improved?) design. The new design has a smaller hole at the end.

Each valve will come with a rubber o-ring and is oiled from the factory.

To install, just press the valve in and then torque the bolt to .66 ft/inches.

Do NOT over torque these bolts or they will snap! Guess how I know? Like everything else in this engine bay, everything has been cooking for a long time, so things have become brittle and fragile. If you do happen to snap one of these, just buy an M6 hex bolt with a 1/4" washer and it will be a direct fit. I got my bolt at Autozone. To get a replacement bolt from Toyota is a 10 day special order wait.

[richardkwon]

After all your tube seals are installed they should look like this.

The first 3 seals took me an hour or so. I did not like the way the non OEM seals looked, so redid with OEM. Once you get the hang of it, it is very easy and should not take you more than 5 minutes for each seal. With a little practice, you too can become a pro!

[richardkwon]

To prepare the bolts for reinstallation, you will need to remove the grommets, which are now rock hard and no longer pliable. As the rubber has now turned to brittle plastic, they will no longer come off the bolt by hand. To remove, grab the grommet with some pliers and using a 10mm socket wrench, remove the grommet This is fairly tedious as there are 18 grommets.

After the grommets are finally removed, clean all the bolts of oil and plastic debris using brake cleaner.

Now as to why the VC bolts get so loose? Well, the bolt grommets are made of soft rubber. Put 100,000 miles of intense heat and 15 years of age and guess what? You get nicely cooked grommets that turn into rocks! Then put a little oil on them from the leaking VC and soon due to engine vibration, they start magically coming unloose!

Make sure you torque the bolts to 55 inch/lbs.

[richardkwon]

Now, install a fresh new PCV valve and grommet. Taking the valve and grommet out requires a lot of muscle. Installing them takes the muscle of a gorilla and the intelligence of a human. Actually, it's not too bad and is definitely easier when the VC is off the cylinder head.

First, remove the PCV valve separately and then the grommet. The grommet will be fairly hard due to age and heat. Using pliers, remove the PCV valve first. Then grab the grommet from the edge and remove it. It will take a bit of finagling and wriggling around before it finally pops out. If it is still hard to remove, you may want to cut a piece out first. Try not to drop it in the VC housing.

To install, first assemble the PCV valve and grommet together. Then apply some soapy water to the grommet and then insert into the hole/housing. Believe me, it's not that easy. It took a lot of finger muscle to get it halfway in. And I could not use all my force for fear of breaking the plastic elbow piping. I had to resort to using a large plier to grab the edge of the grommet and use the spark plug tube hole for leverage.

[curiousB]

Richard,

Some really terrific work here and to the benefit of others down the road. Nice job!!!!

[richardkwon]

Thanks CuriousB. The LS400 is truly a fantastically engineered car and well deserving of fresh VC gaskets!

[billydpowell]

Well. Jon just replaced my VC gaskets, and I was surprised not to see ANY sludge, with 230k miles on the engine. did not remove the oil or tranny tubes, it all went smooth, and was needed...

[richardkwon]

To install the VC gaskets, each rubber gasket will have several evenly distanced outer rib/nipples that run along the entire gasket and allows the gasket to stay in the VC valley when it is turned upside down to install. This is great so that you don't need to worry about constantly making sure the gasket does not fall out. No need to apply FIPG to the VC. Just apply the new FIPG to the 2 corners near the cam housing. See the pic. Press down and torque the bolts to 55 in/lbs by making several passes on each bolt. To torque the bottom bolts, I found an 18" extension with a swivel attached to the 10mm socket to be the most easy way to remove and tighten.

Connect all the hoses and voila, no more VC leaks for hopefully several more years.

[Legender]

Richard... excellent work.

I look forward to bringing my 1999 over so you can get some more experience. JK...

Great info and pics. I know it takes time to do this and the rest of us really appreciate the effort you put into this.

I liked your idea of a rubber tube to remove the plugs... I ran into this a long time ago on my daughter's Honda Accord.

Then I found when I replaced the plug wires, I could cut over the wire part and use the long plug connection as my new spark plug tool to remove and insert spark plugs. It's a perfect fit as it was made for spark plugs. I keep a couple in my tool box all the time.

Thanks again for the great info..

[billydpowell]

very nice write up, mine has 231k now and I had my nephew Jon replace the VC gaskets, seals, & grommets, and was surprised how clean everything was.... no build up at all. we also cleaned the OCV's and made sure they had good snap action. no more oil leaks...

[Micah.Berry]

Richard,

Wow! Very nicely done write up! Good pictures too (for those of us who are more visual learners)! Thanks a million.

Micah