Ticking sound from engine when warm at low rpm (Page 1/2)
Xenoblast MAY 25, 07:27 PM
1987 Fiero GT 5 speed

After a timing chain exploding on the highway, I towed it home and fixed it. When I started it, there was a loud ticking sound when started cold, and lasted like 15 seconds before slowly disappearing. Sounded like it was from the top end. I used 5w-30, and I put lucas oil stabilizer into it which stopped the cold tick completely. Now, when the engine oil is warm, there is an inconsistent (changes in pitch at random) ticking sound which sounds like its coming from the top end, and only linked to RPM. The sound does not change with load. The sound disappears somewhere over 2k RPM. I have driven the car 600 miles like this and the sound has not gotten any worse or better.

What could it be? Im thinking its a hydraulic lifter problem.

[This message has been edited by Xenoblast (edited 05-25-2021).]

Patrick MAY 25, 07:53 PM

I not saying it isn't a lifter you're hearing... but sometimes a cracked exhaust manifold by one of the ports will sound very much like a lifter tick.
Xenoblast MAY 25, 07:58 PM

quote
Originally posted by Patrick:


I not saying it isn't a lifter you're hearing... but sometimes a cracked exhaust manifold by one of the ports will sound very much like a lifter tick.



I just fixed my front manifold cracks like 4 months ago. Could every well still be that, but I dont think it would crack under such short amount of time. Still, when I have the chance I will look back there.
Mike in Sydney MAY 25, 10:04 PM
My money is on a faulty hydraulic lifter. My '97 Holden Jackaroo (Isuzu Trooper) clicks and ticks like a castanet player on drugs until it warms up. Then it goes away. With 300K on the clock, I'm hesitant to remedy the problem until I need to rebuild the engine.
Xenoblast MAY 25, 10:47 PM

quote
Originally posted by Mike in Sydney:

My money is on a faulty hydraulic lifter.



Question, what do you think I should do? Do I just deal with it, or get heavier weight oil, or replace the lifter, etc?
Skybax MAY 25, 10:55 PM
I would definitively isolate the noise first using a stethoscope or heater hose to your ear.
Xenoblast MAY 26, 01:56 AM

quote
Originally posted by Skybax:

I would definitively isolate the noise first using a stethoscope or heater hose to your ear.



I did this, and I think its coming from the right side of the engine where the timing chain is in the middle. Like next to it, not the chain itself. It was hard to hear over the transmission making noise tho.

[This message has been edited by Xenoblast (edited 05-26-2021).]

Patrick MAY 26, 03:47 AM

quote
Originally posted by Xenoblast:

It was hard to hear over the transmission making noise tho.



Ah yes, the infamous Getrag rattle. Perhaps find someone with a heavy foot who can disengage the clutch while you're listening to the engine.

If you're using a mechanics stethoscope, I find that the rod attachment/probe is a whole lot better at tracking noises than the cone.
Mike in Sydney MAY 26, 07:44 AM
5w30 seems pretty light. I would change the oil and put in 20w50 and see if it lessens the ticking. You make want to put oil stabiliser in, too. This may "fix" the problem until you're ready to rebuild.
Xenoblast MAY 26, 01:22 PM

quote
Originally posted by Mike in Sydney:

5w30 seems pretty light. I would change the oil and put in 20w50 and see if it lessens the ticking. You make want to put oil stabiliser in, too. This may "fix" the problem until you're ready to rebuild.



Im gonna put seafoam in my oil rn, and change it in a couple hundred miles and see if that helps. Im thinking about putting 5w-40 into it. The car gets 75 psi at cold idle and about 40 when warm. I looked at the guage as i was listening for the sound, it seems to disappear around 50 psi.

[This message has been edited by Xenoblast (edited 05-26-2021).]