Suspicious

I'm new to this forum and american cars/engines in general, I hope you guys can help me

I recently bought a 87' Caprice with a completely stock 305 engine (non TBI, 146k miles on it), unfortunately it didn't even make the way home the day I picked it up...

I drove it for about two hours without any real problems, the engine hesitated a little under acceleration from time to time, but I figured it was due to not being driven for a few month during winter...

As I drove up the freeway from a fuel-stop, I put it back in overdrive and suddenly hear a silent (luckily the radio didn't work :embarrass ) ticking, which seemed to be coming from the tunnel right under the dash...so my initial thought was that the transmission/ TC was getting into trouble.

I took the next exit and rolled down the window as I sneaked the car to the next possible parking spot and heard that the noise was actually really loud outside the car and the idle was way too high in Park and almost stalls when putting it back into Drive ...so I shut it off and called a tow truck.


The next day, something odd happened: I wanted to drive to car a few meters into my garage and the sound was completely gone, so I let it idle for a few minutes and the sound slowly returned, but very infrequent in neutral and completely gone in gear

Later that day, I went to fire it up again and the noise was there again, so I took quick videos:

When you stand infront of the car, the noise is actually more present on the passanger side...



shortly after that, the Idle began to rise again, I guess the timing and carb setup are completely off...

Haven't run the engine since then, It ran about 5 to 10 minutes total with this noise, most of it idling...

As I wrote before, I have no experience with this engines/cars, so I hope someone can point me in the right direction

And please forgive me if some of my grammar is wrong, I'm a german dude doing what I can


Thank you very much

kevinkpk

Sounds like a lifter is stuck

kevinkpk

I'd suggest remove the valve cover from the side the noise is coming from. With your hand shake each rocker arm, if it is a lifter you will have a loose rocker arm. Dosen't sound like anything serious, but if it is a lifter, you need to replace it as running the engine like that will mess up the push rod

Suspicious

Hi,
Thanks for the answer!
Alright, I'll check that as soon as possible...man I hope it's just a lifter, not being able to drive that car is a real bummer as I was really looking forward to it...
When standing infront of the car, it is pretty clear that the sound is coming from the passenger side bank, I'll keep this updated as soon as i checked what's going on under those valve covers

kevinkpk

Best way is remove the valve cover, rotate the rocker arms, these will be "loose" unless the valve is not closed. If you can rotate the rocker arm off the push rod, that's a problem. When you find the one (if it is a lifter) use a telescoping magnet to remove it, very easy. Good Luck!

kevinkpk

You also need to hook the crank case vent line back up. It's the plastic end out of the air breather. It should have a small filter inside, and a tube that goes to the valve cover

Suspicious

Alright, I removed the valve cover and checked the rockers, they were all rather tight except for one which I could slightly click from left to right, but none could be taken from the pushrod or get compressed by hand..the loosest one isn't even near the source of the sound, since it's more present at the second cylinder of that row and the loosest rocker was the last of that row...
Is there any other way to check the lifters? or should I turn the engine by hand and check the rockers with the crank/camshaft at different positions?

Thanks

kevinkpk

You need to make sure the knock is at the top end of the engine. If so (this is me how I adjust rocker arms, do this at your own risk) I'll with the engine running tighten the rocker arm down slightly till the knock stops.

Suspicious

Ok, I tried that and I can loosen each rocker arm until it slightly knocks and then tighten it until the knock stops, but the ticking from the videos remains;
The sounds seems to be coming from somewhere right under the intake, right were the cam/lifters are...
The car has been sitting for a while now since I don't run it as long as this issue remains, but as I started it up to adjust the rocker it chattered like a bag of screws for a second, after that just that single ticking remained; it sounded exactly like my old bmw with bad lifters (they couldn't hold oil) after a couple of days without running....

kevinkpk

If your sure it's at the top of the engine, probably a lifter. Two things you can do, first, replace them all, second, and you need to tag which cylinder/intake, exhaust you pull out. Remove them, clean them out in diesel or gas (diesel isn't as flammable) let the set overnight.