Help! Stuck Camshaft Bearing Cap Prevents Me From Replacing Camsha

[Magda]

HELP! Stuck camshaft bearing cap prevents me from replacing camshaft housing plug.

Hello, Lexusarians
I am new to this forum. Reading your posts helped me a lot in the past.

I have a 1st Generation LS400 1990 with approximately 300,000 miles and counting.

I am currently replacing valve cover gaskets as there was a lot of grime all around it for a few years now.

LH (driver’s side) VALVE COVER is currently off the CYLINDER HEAD.


MY PROBLEM:
I plan to remove and replace CAMSHAFT HOUSING PLUG, which is located in the rear on the firewall side of cylinder head. The plug is covered with BEARING CAP labeled I6. Bearing cap is held with 2 bolts.
I removed those two bolts and thought I would be able to pick the bearing cap up to gain access to the rear CAMSHAFT HOUSING PLUG.
Unfortunately for some reason the BEARING CAP seems stuck. I don’t want to use too much force on aluminum and am hesitant using metal tools to pry the bearing cap off.
One try was to insert the bolts into the holes using them to wiggle the cap off, but it didn't wiggle out at all...
I'm thinking of some kind of a spreader? but the space is limited and I cannot seem to find a proper tool.

Do you have any suggestions? What should I do? Not too much space there.

Regards and thanks!

Below are some pics.















By the way: I also removed HALF MOON PLUGS made of metal sitting flush on the cylinder head surface edge. Space filled by one of them is visible on some pics.
Interesting tip which helped me remove those HALF MOONS: take a piece of wood like a short wooden stick, place it on one side of half moon and then hit the piece of wood gently with a hammer/rubber mallet so the half moon breaks the seal and starts moving in a round fashion. Once it has moved a bit you can take it out with your hand.

[landar]

That was a good idea to try wiggling the bolts in the cap holes but I think I would probably do your other tip: take a rubber mallet or wood and gently tap the caps where the bolts attached. Tap one side, then the other, working back and forth until it breaks loose. Using a rubber mallet should be gentle on the aluminum. Still, I would not bash on it too hard. Just use some gentle but forceful tapping back and forth, front side and back side. If you cannot get the mallet head in there, you might use a wooden dowel pin to reach the cap. If it still won't come out then back up and revisit what might be holding it.

BTW, was it leaking oil back there?

[Magda]

Hello Landar,

I secretly hoped you would be the one answering my post ;) I value your expertise! Thanks for taking your time. Will try your suggestions. I didn't expect the bearing cap to be so stuck...

It's hard to say for sure if it was leaking oil back there. I had a lot of oil grime around the entire edge all around the valve cover gaskets. Oil grime was also all around rear camshaft housing plug and its bearing cap, including the contact of bearing cap with cylinder head.

My thinking was: the car is 25 years old. I am doing valve cover gasket anyways which probably has never been redone on this car. Half moon plugs and camshaft housing plug thus should be done while I'm in there.

Now, that I have unbolted those two bolts and already tried to wiggle it, I feel I have no choice but to replace the camshaft housing plug as I might have created leaky surface by trying to detach the bearing.

I will keep you posted.

Thanks again!!!

[VBdenny]

Hey Magda,

You may own one of the best cars ever made. I see mine 90 LS around every day and still miss that car. Something my wife and I both agree on, the 90 LS400 was the best driving car we have ever owned. Keep that 4Cam going.

[Magda]

Thank you, Denny.

I love my ls400. It really is an amazing car. Offers smooth, relaxing ride with the power of v8 when you need it. It's 25 years old and still pretty reliable and very quiet ride. Will try to keep it on the road as long as possible. :)

Regards :)

[Exhaustgases]

I have had that one off, and don't remember it was a few years ago. I would use a mirror and check to make sure there isn't a bolt going through a bracket in the rear towards the fire wall. To late to go study stuff right now.

[Magda]

Thank you Bob,

I actually forgot to mention that I removed the bracket held by small bolt in the back. Otherwise I wouldn't have enough space to unbolt two bolts holding the bearing cap. The cam bearing cap is still stuck as of now.

[Magda]

I managed to remove the LH rear bearing cap by placing wooden stick on the bearing and tapping wooden stick with a hammer / mallet. I tried to be gentle. It helped to tap the front edge of the bearing directing the tapping towards the rear / firewall... I tried to be gentle. I first tapped on the sides with bolt holes but it didn't seem to work...















I was thinking of doing cam seals as well...
But I'm not planning to do the timing belt now thus cam seals will have to wait. However, do you think I shoud remove the front cam bearing caps (=the ones close to the timing belt) to reseal them with FIPG, even though I'm not doing the cam seals? Valve covers are out and I want to reseal with FIPG as much as possible without doing any damage. The Repair guide says that RH I6 front bearing cap determines the thrust portion of the camshaft. The same applies for LH I1 front bearing cap. Would I change the thrust by removing and resealing them? Any ideas?

[sha4000]

After I did the cams seals on my car and started putting things back together I over torqued one of the cam pulley bolts and snapped it off. I had to remove the front bearing cap again so I could access the back of the bolt to get it out. The FIPG had not fully cured yet. Afterwards I just put the bearing cap back on and have had no ill effects since.

[Magda]

Interesting... In such case I may attempt to seal front cam bearing caps without doing the cam seal... This way my valve cover gasket job may be more complete... Valve clearances are probably too advanced for me.

[landar]

If not leaking, I would just leave those front bearing caps alone. Do it right when you change the timing belt. No FIPG.

[Magda]

I thought about it a bit. Under the front bearing cap I have a very old Cam Seal that may be leaking... If i take the bearing cap off now to reseal it with FIPG, I risk creating big leak in old Cam Seal... I do not plan to replace cam seal now. Thus it probably is not a good idea to move front cam bearing...

If bearing leaks really bad in the future, I will redo the valve cover gasket and get to it when new seal is in... not sure what is the best way.

Regards and thanks everyone for all helpful and well thought out responses :)

[sha4000]

If not leaking, I would just leave those front bearing caps alone. Do it right when you change the timing belt. No FIPG.

Why do you say no FIPG landar. In the manual for my 98 it clearly states to remove all the old FIPG and place seal packing to certain places on the front bearing cap. The FIPG was the reason it was so hard to break loose. I just assume that the 90 procedure would be no different even though I don't have the manual for a 90.

[Magda]

My instructions also say that FIPG should be placed on certain surfaces of bearing caps as well as on corners of valve cover gaskets and over half moon plugs...

PROGRESS UPDATE:

The valve covers are currently off on LH (driver) and RH (passenger) sides...

LH valve cover was relatively easy to remove.

RH valve cover was a pain to remove due to a huge wiring harness running above the entire rear of passenger side cylinder/valve covers. --> Any tips on that? I'm worried that it will be difficult to put RH valve cover with a new gasket back in smoothly, without messing up the gasket placement. This wire bracket is huge and wrapped with old, cracked, peeling off remnants of what was an electrical tape 25 years ago... Some of it will definitely end up falling into the exposed cylinder head...

My Lexus LS400 1990 has stupid metal brackets behind cam housing plugs on LH and RH sides.

On LH side it is held by one very inconveniently located 10mm bolt. I managed to get it off in order to have more space to play with cam bearing and its 2x10mm bolts. At this point LH cam bearing is off as well, like I previously reported.

However, on RH side the metal bracket , which blocks 2x10mm cam bearing cap bolts is held by 2 bolts in the back of cylinder head facing firewall, both bolts for this bracket seem impossible to unscrew... especially one of them.

--> Does anyone have any idea what to do to unscrew this stupid RH bracket behind rear cam housing plug?

I really want to replace both plugs... but I may be unable to, which is not the end of the world. I can live with oil leaks.

Maybe no one knows how to replace RH cam plug because it is impossible and no one does it. lol!!!!

Thanks for suggestions / solutions :)

[landar]

If not leaking, I would just leave those front bearing caps alone. Do it right when you change the timing belt. No FIPG.

Why do you say no FIPG landar. In the manual for my 98 it clearly states to remove all the old FIPG and place seal packing to certain places on the front bearing cap. The FIPG was the reason it was so hard to break loose. I just assume that the 97 procedure would be no different even though I don't have the manual for a 97.

I should clarify...I meant no FIPG without changing the seal as well. It is ok to use some FIPG as the manual states but I would go very easy on it. I just dislike the messiness of FIPG although its a cheap way of sealing. The factory uses FIPG for the transmission pan seal but when I pulled the pan and changed the filter, I put the pan back in with a gasket and stayed away from FIPG. Same for the water pump.

So, I did not mean to imply that you should never use FIPG, I just do not like to go crazy with it like the factory seemed to do. You can get a good seal with the proper gaskets and a minimum of FIPG.

[landar]

Magda, I feel your pain.

On the brackets, it *may* be possible to just bend them out of the way but not sure w/o looking. I have done that before on certain brackets, then just bend them back later. Those bolts are in a tough place. You just have to reach back there and do it all by feel. Takes a lot of patience. I have never tried to replace these back plugs as they were not leaking and I just left them alone.

As far as putting the valve cover gaskets back in place, I usually place them inside the valve cover first and then set the cover on the cylinder head. This is where FIPG may come in handy to hold them in place.

The wiring harness is a pain as you can see and very brittle. These feed the fuel injectors among other things and you will need to try and slip the valve cover underneath/over them or you will need to remove the brackets holding the harness. We changed the valve cover gaskets when re-doing the starter so the entire intake manifold and harness was removed. I 'broke' a couple of the clips for the fuel injector connections because they were so brittle but just plugged it back together w/o clipping and it runs fine.

[sha4000]

I would just pull ALL that old tape off so there's no chance of it falling in there. That's what i did after the fact. Little pieces if tape kept failing in and I had to use needle nose pliers to get the little pieces out. When I put it back together I just peeled ALL the old tape and put new tape plus slid those wire protector things over them. I forget the exact name. I wold also try to bend the brackets back some to give more clearance.

[Magda]

I put plastic wrap over exposed cylinder head and over wire brackets to reduce the danger of contamination for whatever is exposed while valve covers are out.

Here are some pics of inaccessible wire bracket blocking access to bolts of cam bearing cap on RH side (passenger).

Inaccessibility is the reason why pictures are not that great.

[landar]

I just looked at my sons' 92 LS400 and think I see the bracket. Those two small bolts in the top of the bracket which you have removed hold the wiring loom. It also looks like maybe there is 1 - 2 inches of clearance between the back of the bracket and the firewall. It is a tough, tight spot to work. I think that bracket is formed heavy gauge sheet metal so I would still try prying that bracket back toward the firewall to see if you could gain enough room to work. When done you can pry it back into place. If you feel uncomfortable doing that, you will need to get at the bolts holding the bracket. Thats about the best advice I can offer at this point.

[Exhaustgases]

RH rear cam plug, the most likely option is to remove the transmission mount and lower the rear of the engine down. Some times the simple things are the hardest. It may even involve removing the engine.

[Magda]

Hi All,

I do this job slowly as I have other things in life apart from car repairs ;) so please, bear with me! LOL

I have bent the RH metal bracket. Then I removed the bearing cap and its plug.

I am now ready to reinstall rear camshaft housing plugs on LH and RH sides. I removed old FIPG (which was milky/yellowish) in color) cleaned surfaces with alcohol.The only doubt is that the rear camshaft housing plug (metal plug covered with rubber) is a bit bigger than the space I'm putting it in. I tried to push it down in its slot in the end of cylinder head, but it feels like it does not go all the way through. I don't want to use FIPG on the plug as the manual/protocol does not mention it at all. I even found on some other forum that the plug should not be sealed with FIPG. However, some people use FIPG on the plug itself...

I plan to put rear cam plug in its spot on cylinder head even though it will not be pushed all the way. Then I will put FIPG only in proper place on cam bearing cap surface that meets cylinder head. I will then put bearing cap on top of cylinder head and a plug. I hope torquing the 2x10mm bolts on bearing cap will push the PLUG in so that it creates a proper seal...

Let me know if my thinking here is correct. There is not a lot of info on the plug in terms of proper installation technique.

Regards and thanks again.

[landar]

The plug is not going in because it it new and is an interference fit part. I would try to press it into place (I am guessing there is not enough room to tap it in). You might be able to find or make a simple tool to press it in. Like a piece of PVC (a coupler maybe?). Using a pry bar against the firewall and PVC tool, you may be able to work(press) it into place. Just a thought.

[Magda]

I placed the plug in its place in cylinder head. Didn't manage to press it all the way in, but pressed it down as much as I could. Then I put the cam bearing cap on plug and cylinder head. Then I bolted to the required torque. I hope the torque pressed the plug in its place. The valve cover gasket was also done at the same time. Only time will tell if those oil leaks were eliminated. ;) Will post the update in a while.

Thanks for all your help!!!!

[sha4000]

Can't you put a mirror back there to check.

[Magda]

Hi Craig,

RH side cam plug is in a very inaccessible place and no space for mirror there. But will check in a while if valve cover / cam plug leaks are fixed. I may try to get smaller mirror to monitor the situation.

I have another problem with the car now, which LS400 developed after a series of bundled repairs...

LS400 idle loops up and down from 1100rpm to 1600rpm every 3 seconds. I created a new post for that.

http://us.lexusownersclub.com/forums/topic/86818-ls400-idle-loops-up-and-down-from-1100rpm-to-1600rpm-every-3-seconds/