Jump to content
Ultimate Subaru Message Board
Sign in to follow this  
pyromanic

TOD or piston slap?

Recommended Posts

How do I tell the difference?

 

Whatever it is, the engine runs quiet when it is completely up to operating temp. Not untill then. Shut it off for 1/2, the darn ticking is back. Pretty loud too.

 

Have tried MMO. Gunk brand "valve medic". 10w30. 15w50, and others. No help. This 1985 NA, EA-82.

 

 

 

Pyro

Share this post


Link to post
Share on other sites

ea82 motors dont usually have piston slap. Sounds like the TOD...

 

Reseal the oil pump (If its within factory spec.) or replace the pump. I replaced my pump about a month ago. If yours has never been changed, its about time for it. 20 year old oil pump.

Share this post


Link to post
Share on other sites

over time, the rotor wears out due to impurities in the oil. This ends up leaving too much of a gap between the rotor and the engine block. This means lower oil pressure, which causes the HLA's to not pump up, or be able to maintain their pressure.

 

I resealed my pump 3 times with no luck of stopping the TOD. That's why I said replace the pump if it was out of spec. If you have the pump off to reseal anyways, why not run a feeler gauge on it and see if it needs replaced.

Share this post


Link to post
Share on other sites

I forgot to mention that I have pretty good oil pressure, for what it's worth. 70 when cold. never drops below 20, hot engine, at idle. This is on a good full sweep mechanical guage, new. between 50 and 60 when curising. does this hel with diagnosis?

 

by the way this is one, quite loud ticking sound. Not a clatter. One loud ticking.

 

Also, best friend is a very experienced mechanic. (I'm not saying he's good, just experienced, though not whith Soobs) Tonight he told of his "test" to determine piston slap from lifter ticking.

 

He said to start engine, pull plug wire. If you find one that makes the ticking goes away, it's piston slap. If it doesn't, it's a lifter. Is he full of beans?

 

I went out and pulled them one at a time. Ticking remained.

 

So would a collapsed lifter keep ticking if that cylinder had no spark, or not?

 

I get his theory that if it was piston slap, it would shut up when not under power. But I don't know if it's true.

 

Comments please

 

 

 

 

Thanks guys.

Share this post


Link to post
Share on other sites
yes a lifter will still tick without spark. they are ran by the cams/valves moving

 

and if it WAS piston slap, the ticking would shut up without spark?

 

Pyro

Share this post


Link to post
Share on other sites

pyro - k heres what we are going to do.. we are going to take this word, piston slap and send it to the new forums. these old cars dont usually have piston slap. replace the oil pump seals and if that doesnt fix it, replace the pump.

 

enough said

Share this post


Link to post
Share on other sites
pyro - k heres what we are going to do.. we are going to take this word, piston slap and send it to the new forums. these old cars dont usually have piston slap. replace the oil pump seals and if that doesnt fix it, replace the pump.

 

enough said

 

OKOKOKOK! Got it. I'm convinced. I believe.

 

Sorry to be so stubborn. My ancestors are from the "show me" state. I take little at face value, and it makes sometimes hard to get along with. I apologize for being annoying.

 

After several hours of reading and research, I ansewred my own question. Apparently it's true that most bottom end sounds will "evaporate" when spark is removed. Not so with valve train sounds.

 

As usual, I recieved good advice here. I should learn to trust more. You know, "old dog, new tricks".

 

Thanks Torxx.

 

I was gonna start tearing down the front of the motor this morning, but two inches of fresh snow!!! Crap.

 

Pyro

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×