my living nightmare. valve cover gasket replacement turns into engine out job (4 Viewers)

[excessive]

Let me start by saying that i feel i am a fairly competent mechanic. I have been working on cruisers (and other cars) for over 20 years. I have even rebuilt a 1Fz-Fe engine in one of my 80 series in the past. I know my way around, or at least i pretend to.

I went to replace the badly leaking valve cover gaskets on my 2004 Lx470. The driver's side rearmost valve cover bolt broke off in the head. I have spent probably the past 25-30 hours trying everything in my arsenal to extract it. I have attempted welding nuts to it several times, and gotten no further.

The bolt was almost out when it broke, only the last 1/4" of threads are stuck in the head. the problem is there is so little room to work in the area. I even bought a right-angle drill, but there are less than 2 inches between that bolt surface and the body of the vehicle, so there is no chance of a right-angle drill getting in there.

I've contemplated slapping it back together, and rolling it off a cliff. Not really... but i did fantasize about it. THis truck is almost fully built, lots of time and money invested in it. And it only has 150k miles. I want to save it. I am the type of person that does things to the best of my ability, only use OEM parts, etc. I don't want a permanet leak in my valve cover gasket... so I have resigned that i will be pulling the engine to properly fix this. I already have a hoist and everything i need. except the 30 more hours of free time

A few questions. I did some searching, and there are almost zero threads about pulling the engine on the 100 series. I read the Toyota FSM, and they describe the procedure with pulling the engine and trans together. Been there, done that with the 80 series, and the whole unit all together is just sooo big and heavy to deal with . I would rather disconnect the trans via the torque converter bolts/ bellhousing bolts and leave the trans it in the vehicle. Does anyone know if this is possible?


FML

 

[excessive]

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[awesomeissquid]

Quick answer is yes it is possible to pull just the engine. @2001LC has a walk through of this process in one of his threads (maybe emerald?).

Regarding getting the remaining bits out have you tried using some epoxy to glue a bolt to it? I know you said you tried welding a nut, but I am thinking maybe there was not enough space for that. Maybe with epoxy or some from of glue from the bottom even since they are through threaded you may be able to get it to work?

 

[bj70bc]

milwaukee 90 degree chuck and reverse drill bits

you can cut the bits down if you have to and re grind the tip
you can get the bits on a 1/4inch base to fit that bit chuck

i just measured it and with the smallest bit its just over 2.5"

start on an angle or 'clearance' some more room for this unit

 

[97 AZ LC]

How about cutting a slot in it with a small Dremel cutting wheel even if you damage the surrounding face a bit. Anything that would grab it with a rounded off screwdriver blade or a small punch. Of course soak it overnight with PB Blaster, etc. That's a strange one that it would get so tight when it was almost out.

PS - Maybe a Dremel 199 - Amazon product ASIN B00004UDGP

 

[3_puppies]

you could remove the 2 front motor mounts and drop the engine a bit and that should give some more clearance without removing the engine

you can remove the engine without the trans, but it is almost easier to do it as a combo, less stuff to disconnect, especially the plastic connectors for the trans behind the engine.

 

[excessive]

I love this forum, and the folks here. thank your for all the replies.

I hadn't thought of taking out the engine mounts to lower the engine... that might just work!! hopefully the exhaust wont get in the way of lower it. we'll see. I will try it this weekend. Thank you for the great tips.

 

[badlander]

The same bolt broke on mine. I was finally able to get it out by using a 90 deg drill attachment connected to a 90 degree drill. The one which was able to access the broken bolt was a Dremel attachment wirh the short dremel drill bits. The other was a cheap right angle Harbor Freight air drill which drove the Dremel unit. The air drill was positioned vertically with the chuck pointing rearward and the dremel attachment connected to that just barely had clearance to reach the bolt straight on.
Thr Dremel unit is pretty flimsy so you have to go easy with it but in the end it got the job done for me.
I made a pilot bushing which fit into the exposed diameter of the threaded hole to guide the drill on the center line of the bolt. Once I had a thru hole in the broken off bolt I switched out the drill bit for a tiny dentist drill type of die grinder tip and ground out very thin slots in the front and rear faces of the bolt. Finally I was able to tap free the 2 now seperate pieces and I was home free. The slots cut into the threads in the head also but I made that sacrifice considering the small percentage of thread loss. I initially tried only one slot thinking it would take the pressure off the broken bolt but it was still no go. The second slot allowed both halves to come out easily. I didnt have to try and screw it out.
It was not an easy task, I kid you not. A simple job turned into my worst nightmare, just as you are experiencing.
The last resort for me, if I couldn't get the bolt out, was to make a c-clamp out of 1/2" crs with a small bolt nib on the bottom side to keep it aligned in the bolt hole in the head, and a tightening bolt on the top side to press down on the head, and just run with it. NO way was I going to remove the engine for that. I think even if the clamp didn't work, which I'm sure would have, I would rather put up with a minor oil leak then pull the engine.
Anyway, good luck with whichever solution you pick.

 

[97 AZ LC]

Or drill a hole at an angle in the edge of the bolt with a Dremel drill bit. The angle and the small tool give you more room to work with. Put a small punch in the hole, tap the punch with a hammer.

 

[SteveH]

The last resort for me, if I couldn't get the bolt out, was to make a c-clamp out of 1/2" crs with a small bolt nib on the bottom side to keep it aligned in the bolt hole in the head, and a tightening bolt on the top side to press down on the head, and just run with it.

I thought of that, too, and I think it's a very sound approach if all other approaches fail. Is it fancy and cosmetic? No.

 

[ClassyJalopy]

This pic makes it looks like the hole is through to the other side and the other side is open (as in it's accessible from the bottom)? If that it true, I'd try and drop the engine a bit lower and drill through without much regard for the threads. Once you have a through hole, you can put a through bolt with a nut on the other side.

 

[nissanh]

Above is what I've been thinking too: Even a 8 mm nut and bolt would hold it. If you pull the engine out.... as a Mudder and your passion to fix things right with oem... be ready to break the bank! I can tell where this will head for simple bolt extraction vs.. replace... this and that "while" the engine is out!

 

[riffman12]

If none of the above works, could you just pull the head instead of the entire engine? This guy has a very detailed 4 part video on how he removed heads on a 4.7 4runner which is hopefully a similar procedure?



At least with the head out you'd have more room to work with.

 

[nissanh]

Issue with fixing one head (with a complete head job), the driver's bank will have perfect compression while the pass is not can cause some vibrations. Since OP has no symptoms of head gasket issues, my advice would be to pull the engine if all options fail. Best would be to drill and at least install a self tapping screw there.

 

[rock climber]

I have no advice, but man that sucks! I'll send happy healing thoughts to your truck!

 

[Mike NXP]

This pic makes it looks like the hole is through to the other side and the other side is open (as in it's accessible from the bottom)? If that it true, I'd try and drop the engine a bit lower and drill through without much regard for the threads. Once you have a through hole, you can put a through bolt with a nut on the other side.

It looks like the angle is still favoring the engine side so coming from below may still be tough to get the drill in there, nice and squre. Would have to remove exhaust probably as well?'


OP mentioned just a few inches of space from above, not many options I can think of other than coming from below or having to pull engine but hopefully someone else will have a better idea

 

[Patron100LC]

Looks like a really frustrating situation, hope you figure it out.

Temporarily removing the motor mounts should give you about an inch of additional room, and if you combine it with lowering the crossmember where the transmission mount is bolted to, you might get some more space. It'll be very wobbly there, you want to support everything using steady stands or wood blocks, go one by one and support before proceeding, and keep an eye on the cooling fan, remove/release the shroud before attempting that. Also keep an eye on the transmission links not to mess them up. I'd consider that a 2 people job, or a 4 eyes job actually.

But before attempting that, I'd try some cold weld on the bolt, and heating up the head a bit to see if the expansion of the aluminum together with some mechanical movement of the bolt back and forth will get that piece moving out in the threads. As others mentioned, trying to cut a slot on the bolt and using a tiny screw driver, or continuing the painful attempts to insert a bolt extractor in that limited space, as hard as it is, It's better than removing this engine.

 

[medtro]

I am not close to my car now but I would look into removing body panels first before pulling the engine.

 

[abuck99]

I love all the comments - here’s another—-

Pull the engine, replace the starter and other hard to reach components while you’re in there.

I dread the day I have to the valve covers. I’ve checked the bolts and they are all snug, like frozen snug, so I suspect I’ll have the same issue.

I think these freeze up because the back side is open to environment and the ends of the bolts get crusty which get hung up on their way out. Maybe a dab of grease on the underside of the bolts a few weeks before removal will help loosen up the crust enough to back out the bolts with out breaking.

 

[OwnerCS]

you could remove the 2 front motor mounts and drop the engine a bit and that should give some more clearance without removing the engine

you can remove the engine without the trans, but it is almost easier to do it as a combo, less stuff to disconnect, especially the plastic connectors for the trans behind the engine.

+1 for lowering the engine to get to the bolt.