UNLUCKY?

[Bill]

Ok: I can’t be the only one this unlucky! My ’90 has 110k miles. Last week while driving into town the engine started ticking. To me it sounded like a collapsed lifter. I localized the noise the area of #7 cylinder. Further inspection reviled a missing screw on the secondary throttle plate for that cylinder. Has anyone had this problem? Were you able to recover the screw without pulling the head? Can the head be removed & replaced without taking the engine out of the car?

[WB9MCW]

so sorry to hear of your plight Bill...but I can say no lifters in the LT-5 to worry about...but I bet u knew that...lol...It will be interesting to see if any one else has had this problem and if indeed the missing screw has screwed up anything...I hope it turns out as an easy fix for you. i would see what jeffvette and the PNW boys have to say...here is a link for you to see abt tear downs...

http://www.pnwzr1.net/PNWZR1.htm

scroll down left index to tear down's section....very nice photos of it all put together by Jeff and the PNW gang...

[tomtom72]

Oh man Bill! Hey those screws are so small there is a chance it could have gone in & out and done nothing.....okay I should take my meds now. What about bringing 7 to TDC and go thru the plug hole with a magnet. Man if you could find/ or make a flex shaft to put a magnet at the end & fish around on top of the piston.

Okay wishful thinking. I'm fairly sure guys like John (phroggs) say you can do a head pull without r&r'ing the lump....maybe worth a call to Gordon to seek his opinion. Hey Brian, I thought LT5's had hyd lifters, no rocker arms, and the lifters are the same dimensions as the lifters in the Aurora V8....I remember that from a thread in this forum...I think I read that here? Maybe I read it over at CAC....oh, maybe worth a call to Mr. Haibeck also.

If you were closer I'd say I'd come over & help! Hey, I have a DVD of the training tapes for the LT5 tech training program...say the word & I'll mail it to ya...you could copy it...I would do it but my write drive don't work!

Shout at me if you want the DVD!

Tom

[Corvette95]

Let us know what happens, also if its not too much trouble , could you post a picture of the missing screw area?

[Bill]

Thanks for the replies. Thanks also Brian for the link, I’ll look into that. As far as the lifter I was not sure what was there. Now I know it’s a silver mini hockey puck, at least that’s all I can see.

Tom Your right the screw is so small. But my luck it didn’t pass through. I have tried going through the plug hole with a magnet, no luck yet, still trying. I am just about to the point to start pulling the head, I am most worried about timing the cams when it goes back together. I have the video and will watch it again, also have the service manual and more reading is in order, Thanks for the offer of help, but we couldn’t be farther apart and still be in the same country. I’ll save a call to Mark until I really get in trouble!

Corvette 95 here are some pictures I’ve taken up to this point
1st is a look down #7 secondary bore at the throttle plate before removal.


Next is the removed plate and the other screw from the plate.


Last is looking down the #1 primary bore at the open intake valve. That itty bitty screw didn’t even slow down getting into the cylinder


BTW the compression is good. Low cylinder is 180# high is 198#. Number 7 is 185#.

Originally Posted by WB9MCW

so sorry to hear of your plight Bill...but I can say no lifters in the LT-5 to worry about...

Bryan you still have lifters to worry about. Although they look nothing like the regular SBC lifter.

Originally Posted by tomtom72

Oh man Bill! Hey those screws are so small there is a chance it could have gone in & out and done nothing.....

Highly doubt it, as the quench area is relatively small. Those screws can cause a lot of damage to he head surface, and will gaul the side of the liner if wedged in between the piston.


Bill, the question is, how did the screw come undone? Also, trying to fish it out is a good idea, but I imagine it's already jammed into the head. I'll post pictures tonight of what the damage can look like.

[Bill]

Originally Posted by Jeffvette

Bill, the question is, how did the screw come undone? Also, trying to fish it out is a good idea, but I imagine it's already jammed into the head. I'll post pictures tonight of what the damage can look like.

Thanks Jeff, I think?
I don't know how it came loose. I have had the car for about 2 1/2 years and put about 25k miles on including a trip to Daytona. I have not touched any of those screws. My guess is vibration. You are probably right about it being jammed into the head. I hope the damage is minimal and leaves the head useable. I am planning to use lots of red locktite when putting it back together. My biggest fear is the cams. Is it possible to re timed the cams with the engine in the car?

You "can" retime the cams with the motor in the car, but you are better off pulling the motor. Getting the motor out is only about 3 hours.

[Bill]

OK Jeff Maybe 3hrs for you more like 3 days for me. Thankfully I'm retired and time isn't that important. We are off for a weekend cruise near Yosemite in the wife's 90 vert. Any more thoughts or pointers will be appreciated. I’ll check back in Sunday evening.
Thanks all for the comments and keep them comming

[Aurora40]

Oh man... I hope everything turns out ok and the damage is minimal!