Valve Clatter

dug320 · Post by **dug320** » Thu Jul 28, 2005 12:13 pm

Greetings

I am driving at a consistant speed. As soon as I accelerate I get valve clatter for the first 200 rpm (based on the gauge) increase. After that there is no clatter.

I played with the timing for a day and I have reduced the clatter as much as possible. I checked all the valve clearances on a hot engine and they are fine.

What else could it be?

Could it be the advance and or vacuum?

Cheers

Typrus · Post by **Typrus** » Thu Jul 28, 2005 12:22 pm

I'm not exactly sure what valve clatter sounds like, but maybe it could be other parts? Maybe something is loose in your engine? Have you ever run it very low on oil?
Vacuum advancing or any dizzy thing should not affect your valves spacing or the likes?
Maybe bad valve stems? Maybe your cam is worn?

Just guesses from the uneducated in valve sounds >.<

clbolt · Post by **clbolt** » Thu Jul 28, 2005 2:06 pm

You're describing detonation (pinging), not valve clatter. Have you de-carboned the engine? Tercels are notorious for that problem.

simon84 · Post by **simon84** » Thu Jul 28, 2005 5:33 pm

I too have noticed this same pinging sound when I accelerate. It's most noticable on hills. I also played with the timing until it was less noticable.
How do you de-carbon the engine? Will it get rid of the noise or just be an improvement?

Typrus · Post by **Typrus** » Thu Jul 28, 2005 7:03 pm

Look for my "Sea-Foam Treatment" Repair post I'll be writing in about 3 minutes lol.
Check also your spark plugs and your air filter.
Try running a tank of premium and seeing if you see a change.

clbolt · Post by **clbolt** » Thu Jul 28, 2005 9:35 pm

simon84 wrote: I too have noticed this same pinging sound when I accelerate. It's most noticable on hills. I also played with the timing until it was less noticable.
How do you de-carbon the engine? Will it get rid of the noise or just be an improvement?

Carbon build-up in the combustion chambers increases compression and causes hot spots. Carbon also accumulates on the back of the valves. You can run a can of Sea-Foam through the running engine, shut it off, then drive it hard a couple of hours later. That really works to shake things loose. You can also use Berryman's (the liquid, not the spray), or any number of other things, even water. In fact, a properly installed and functioning water injection system will keep the carbon from coming back. Tercels carbon worse than about anything I've ever owned, and they've done it since they were new.

If you can remove all (or almost all) of the carbon, the noise will probably go away... till the carbon returns.

takza · Post by **takza** » Fri Jul 29, 2005 6:34 am

With the late 70's Corolla...you fine tuned the timing by putting it in 4th or 5th at around 1200 rpm and givng it 2/3s throttle or so...expect mild pinging up thru 1500-1700?

When I was messing with water injection...I ran (by mistake) over a quart of water into the manifold over 50 miles. No damage...and it ran OK...but a little weak and a few misses. Oil use improved by 60-70% for the next 3-4K miles....steam cleaned the rings?

Typrus · Post by **Typrus** » Fri Jul 29, 2005 11:17 am

Again, the liquid worries me. Over 50 miles thats very different than a pint in 3 minutes. If done properly the Berryman's B-12 Chemtool works great in spray form. I entailed use in my Sea-Foam writeup. You'll notice I say you can substitute B-12 for Deep Creep and in the float bowl cleaning situation, it works a bit better. You both spray into a running engine and a dead engine in my treatment. It's worked great for me. If you want to try using the liquid form, be my guest. It just doesn't sit too well with me.