It ran fine with two intake valves not opening or you think they broke just days ago? I guess that explains why the other cylinders were rich. How is the fuel/oil getting into the combustion chamber? Have you looked under the other valve cover yet?
CK5
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'92 Camaro RS
- Thread starter USSkoval
- Start date
L98 time.
Martin
Martin
I've got the intake and both covers off now. All I have to go on is hunches.
I'm 99.9% positive that there were no broken or bent pushrods when it was running fine. The problems all started the next day when I cranked it over and tried to start it. My hunch is that maybe an injector stuck open and bled off the fuel into the intake overnight. Then maybe hydrolocked #2 and #8 and bent the pushrods. I think #2 pushrod might have broke right away and the #8 pushrod broke when I was trying to drive it and "clear it out". I definitely heard a noticeable pop/crack at one point. I think the oil on the plug may have been from getting sucked past the rings when the valve wasn't opening.
Now here's the problem(s). I can't find the lower 3rd of the #8 pushrod. It must have managed to go down one of the oil returns and hopefully end up in the pan. I did find all three pieces of the #2 pushrod though. Also, since I don't know for sure what caused all this... will it happen again?
I also discovered that the head gaskets have been replaced, they are FelPro. Someone put a lot of work into the car, just to drive it 30 miles and park it again.
If it hadn't have run so nice before this happened, I would have already pulled the 305. As good as it ran, it deserves one more chance though.
I'm not an expert but doesn't hydrolocking bend/break connecting rods, not push rods?
I would verify those are stock length push rods and stock ratio rockers. Something tells me the center bolt heads used different length PRs than perimeter bolt heads. Been a LONG time though.
I would verify those are stock length push rods and stock ratio rockers. Something tells me the center bolt heads used different length PRs than perimeter bolt heads. Been a LONG time though.
All the perimeter head motors were flat tappet, which is a shorter lifter, longer pushrod
The center bolt truck engines and I think Monte Carlo 305s (87-89) were flat tappet as well weren't they?
Grey area. I’ve seen perimeter bolt motors beyond 87, and rumors of OE roller blocks as early as 88. GM has no idea, nor did they GAF I think
Since you don't know the history of the engine, almost anything is possible. Obviously, this could happen from the springs being too tall, the rockers being a higher ratio or some other mismatching of valvetrain parts, but it's also possible they are just some junk aftermarket pushrods. 
I'm honestly not sure about hydrolocking. Every time I've dealt with it, nothing was bent and the motor simply wouldn't turn.
The complete valve train is correct and appears to be original.
There's probably some exceptions of GM using leftover stuff, but for the most part, the 305's and 350's used in the B, F and G bodies were roller cam starting in '87. Trucks carried on with flat tappets.
Since you don't know the history of the engine, almost anything is possible. Obviously, this could happen from the springs being too tall, the rockers being a higher ratio or some other mismatching of valvetrain parts, but it's also possible they are just some junk aftermarket pushrods.
It all appears original. The heads haven't been redone, just head gaskets that might have 30 miles and 16 years on them. I also suppose those valves could be sticky from sitting for so long.
I'm thinking I'm going to just put in another set of used GM pushrods and screw it back together. If the missing piece of pushrod ever rears it's ugly head, the worst that can happen is the 305 gets wrecked and it's no big loss.
I think this may be it. I just went and manually moved valves, 3 of them were mildly stuck to the seat.
Scratch that. I forgot to check the two with broke pushrods. I put the rockers on them and tried them. They are very very stuck. They move with force, but return extremely slow.
So I've spent the last several hours getting the valves freed up. The #8 intake valve moves perfectly fine now. The #2 intake moves easily, but still feels a little gummy compared to the others. I've been reassembling everything, but leaving the right side valve cover off for now to screw with that valve one last time before I fire it up. I've used a combination of WD-40, PB Blaster and Fluid Film.
I also should say, I no longer have high hopes for this engine. I'm not willing to have the heads redone and the missing piece of pushrod is concerning. This is the first time I've ever reused intake gaskets, lol. If it runs well, that's great. But if it pops more pushrods, at least I don't have wasted money, just my time.
When I was putting the one valve cover back on, I realized how much the rusty old cheap chrome valve covers weigh. That seemed very odd, but then I realized they are chrome covers on top of the factory valve covers. I had completely forgotten that those were available in the 90's.
When I was putting the one valve cover back on, I realized how much the rusty old cheap chrome valve covers weigh. That seemed very odd, but then I realized they are chrome covers on top of the factory valve covers. I had completely forgotten that those were available in the 90's.
Late night update before I go to sleep. The car is all back together, but I haven't started it. What I have done is leave the fuel supply line undone and stick it into a bottle. I let the pump run a few times and the fuel that was collected didn't look too awful bad, but there was a lot of foreign objects floating around in it. Likely from disturbing the line. After running the pump a few more times, there was no more trash coming out.
Before I drove the car the other day, besides the 5 more gallons of fuel, I dumped in about a 1/2 quart of this stuff. So that should have mixed in pretty good in the ~5 miles of driving.
I'll probably dump in another quart of that stuff, along with more fresh fuel. It should be fine, I've used a full quart in my garden tractor's 5 gallon tank and it didn't hurt a thing.
So the plan is, when I get home tomorrow evening, I'll manually bar over the engine a few revolutions. Then start it. If it runs ok, I'll let it just sit and idle for an hour or two, in hopes that there's no more bad gas to screw up my day.
Before I drove the car the other day, besides the 5 more gallons of fuel, I dumped in about a 1/2 quart of this stuff. So that should have mixed in pretty good in the ~5 miles of driving.
I'll probably dump in another quart of that stuff, along with more fresh fuel. It should be fine, I've used a full quart in my garden tractor's 5 gallon tank and it didn't hurt a thing.
So the plan is, when I get home tomorrow evening, I'll manually bar over the engine a few revolutions. Then start it. If it runs ok, I'll let it just sit and idle for an hour or two, in hopes that there's no more bad gas to screw up my day.
Seafoam. My 89 had sat for about 10 years when I started on it. I drained the tank by pulling the fuel filter inlet line (changing filter anyways) and let it gravity flow out. I then put in 5 gallons of fresh ethanol free gas and the proper amount of Seafoam. Knock on wood, I've put several hundred miles on it now without issue.
A dash of Seafoam in the oil probably wouldn't hurt either.
