Intake valve stuck open, now with a VIDEO

[suprarx7nut]

Hey guys and gals, I'm looking for some advice here.

My GTE swap has hit a speedbump. About a week into driving the "new" GTE motor I developed a bad miss. Did a compression test and #3 showed ZERO compression. Sure enough, it's a stuck valve. I can see #3 with an open valve.

Now my problem is I move very soon and dont have the time to pull the head.

What options do I have to try to relieve the stuck valve?

I was going to try to push it up gently using the rope in cylinder trick, pull the spring and retainer, pull the valve stem seal, and then soak the stem in penetrating oil and try to move it back and forth a bit.

I replaced the valve stem seals before i put the motor in, so maybe I caused the stem to catch on the seal or something? :dunno: The motor ran fine before it was pulled months ago by another member so I very much doubt a bent valve or anything like that. It ran well for me for a little bit, then got worse and worse. I'm hoping it's stuck due to simple deposits or the like.

Anyone have any advice short of pulling the head?

-Andy

 

[MDCmotorsports]

Andy, typically valves stick when they bend. Valves bend for a number of reasons. I wouldn't waste the time into trying to "release" the stuck valve. Pull the head, and remove the valve. Install new valve, measure bucket & shim to cam height, and rock on.

 

[suprarx7nut]

Andy, typically valves stick when they bend. Valves bend for a number of reasons. I wouldn't waste the time into trying to "release" the stuck valve. Pull the head, and remove the valve. Install new valve, measure bucket & shim to cam height, and rock on.

Thanks for the quick response, Jon.

I know I should pull the head, and believe me, if I was living here another month or two, I definitely would. I have a spare head anyways and plan on doing it right eventually. BUT... I gotta move and I just dont have the time to pull it and do it properly and I can't trailer it to my new place (It's an apartment complex).

I really cant see how it would have bent though. It worked perfectly to start with. No drama during shim adjustment. The motor has a 1.2mm greddy headgasket so unless it was machined to high hell before I got it, there should be no way the valves would touch. The most the timing was ever off was when it was at ~20btdc when I first started it, but it only idled for about 30 seconds before I shut it down and repositioned the cps. The motor sat for a few months at least before being dropped in so I'm really hoping it just got hung up. AND it ran perfect for a few days before it developed any kind of stutter so I really think the valve went awry WHILE IN CAR, which really makes me think its just gunked up. *crossing fingers*

But I know Jon, that you, and many others here have been around longer and seen more 7M's than I have. Am I dreaming, or is it possible at all that it just got caught up from deposits?

 

[Poodles]

Did you confirm it's stuck by removing the cam cover and checking shim clearances?

 

[hvyman]

Ya spring could have broke.

 

[suprarx7nut]

Did you confirm it's stuck by removing the cam cover and checking shim clearances?

Yes, that's how I knew it was stuck. I took off the cam and there was quite a bit of daylight between the cam and the shim.

Today i spent some time whacking the valve stem to loosen it and sure enough it popped back up. I used the rope trick to give it a little bit of a push from inside. That didnt seem to do much, but then I lowered the rope a little and whacked the valve stem and it came back up.

I'm putting it together now, still need to check compression and I'm sure I messed up the valve clearance by pounding on the valve stem, but the stem moved up and down VERY, VERY freely and the spring is in good shape. I have no idea how it got stuck... :dunno:

 

[Zumtizzle]

<fingers crossed>

 

[89supra7mgte]

Yeah i would def inspect the spring, caps retainers and so on. Maybe even take t belt off and remove cam. I have been sold these are non interference engines, but that may be wrong. 1.2mm gasket, according to what is posted as a sticky that is smaller than stock compressed right? i dont know how much the compression would have raised, but have ran into an na engine (not supra) that hydra locked and bent a valve on one cylinder that had leaky valve seals. think the compression on that engine was like 10:1 or so. Doubt that is the case though.

 

[suprarx7nut]

My bad, the Greddy one on the car is a 1.5. Larger than stock.

So..... I did a compression test:

First: 60 psi on #3.

Not good, but at least it's something.

Second: 60 psi.

Ok, so that's all it's got. Something must be in the way of the valve or the valve is fucked.

Third: ZERO psi wet. ZERO. ZERO, fucking ZERO.

Ugh. The valve must have gotten caught open again. I dont get it. It moved back and forth soooooo freely. What the hell could be causing it to hang up so bad?

For now, I'm going to put it together, unclip that injector and spark plug and just baby it on 5 cylinders to it's new home. After that, I'll get one of my extra heads rebuilt and swap it out. Ugh...

 

[89supra7mgte]

if you eliminate the companion cylinder to that it will run like a 4 cyl. not sure if it will work correctly but it might not feel like such a mis fire. I ran into a guy that had done that on a v8. had hole in piston so he eliminated that cyl and companion and it ran like a v6, no balance issues with mis fires and what not.

But if you do not have far to go then just pulling the injector clip should be good.

valves rotate so maybe the valve is bent and when it is rotated to certain spot it hangs up? or maybe something in the shim cap or whatever?

 

[suprarx7nut]

So here are some pictures and a video of my problem. I still dont get it. It moved so freely, then got stuck again. WHY?!

The only thing I can think of is that the valve gets hung up below where I was pushing it. But I was moving it down pretty damn far. And was only stopping for fear of dropping the valve into the cylinder. I DONT GET IT!!!!


Video:

 

[supraguy@aol]

The bucket itself might be causing the lockup- have you tried checking the freeplay with the shim bucket on??
Oops- i take it back- looks like one pic shows how the valve is depressed without the bucket.

 

[suprarx7nut]

The bucket itself might be causing the lockup- have you tried checking the freeplay with the shim bucket on??
Oops- i take it back- looks like one pic shows how the valve is depressed without the bucket.

Yup, bucket came out just like it should. My magnet sucked it out, just like normal.

This is so bizarre and so frustrating... UGH!

 

[Heavy D]

burnt valve or something?

 

[89supra7mgte]

Maybe there is a slight groove in valve? when you have the spring and stuff off see if you can see anything unusual?

 

[MDCmotorsports]

Andy.

The valve is bent or scored. It works when you press on it because you are over coming the burr on the valve stem, or rotating the valve where the bend sits in the worn out valve guide just right.
There are 103440294372857209587250892742048207 x 99 things that could have caused that valve to bend.
Id say it was either:
-A deposit on the valve stem itself, and when the cam came around it bent the stem
-A weak or broken valve spring
-A broken or worn out valve guide
-Debris inside the cylinder making contact with the valve head
From here, Id say suck it up and get a Uhaul trailer or have the car towed to where ever you are going.

 

[suprarx7nut]

Andy.

The valve is bent or scored. It works when you press on it because you are over coming the burr on the valve stem, or rotating the valve where the bend sits in the worn out valve guide just right.
There are 103440294372857209587250892742048207 x 99 things that could have caused that valve to bend.
Id say it was either:
-A deposit on the valve stem itself, and when the cam came around it bent the stem
-A weak or broken valve spring
-A broken or worn out valve guide
-Debris inside the cylinder making contact with the valve head
From here, Id say suck it up and get a Uhaul trailer or have the car towed to where ever you are going.

Ya, at this point I'm going to have my spare head machined (milled, 3-angle valve job, line hone for cams if need be... etc) and tow the car to its new home. Towing is going to be a BITCH in the new apt. complex though... ugh.

Debating on whether port/polish is worthwhile. I'd have the shop do it and they quoted $250. I've used the shop before for a bunch of stuff and always had good luck. Decisions, decisions...