'91 Loyale Engine Noise

[Keep it in the Family]

Good Morning Everyone.

 

My question is about a noise that I believe is coming from my engine... or at least some rotating component attached to the engine. The sound is a sort of clank, not a tick like lifters make, and it doesn't seem to be rapid enough to actually match the engine rpm..... This being said it DOES change with an increase in rpm. It reminds me of the sound older diesel truck engines make at low rpm or when they are cold. The clanking...... 

 

The biggest problem I have in diagnosing the sound is that it only happens under load, and is the worst at low rpm. For example, when I drive home there is a water/runoff dip in the road right before a hill. So I slow down, go over the dip and accelerate up the hill; at this point in 2nd gear I'm around 1500-2000 rpm.This is when the noise is the most prominent, possibly because there is little wind noise at that slow a speed and the engine noise in limited at that low a rpm.

 

The engine ALSO has a ticking noise that either fades or stops suddenly when the engine is warmed usually. I have (according to the oil pressure gauge) upwards of 65-psi at 3000+ rpm and 15-psi at idle which I believe is appropriate for this vehicle. This I'm figuring IS a stuck lifter that frees up when the engine warms but I thought it was worth mentioning.

 

Any ideas? Thanks.

Edited March 6, 2016 by Keep it in the Family

[Dee2]

The clank noise is likely something has a loose bolt somewhere and rattles at certain rpm's.

 

I had a similar situation once and it turned out to be a loose mounting bolt on the alternator.  Once I found it and tightened, problem solved.  The difficulty is finding it.  You may just have to probe around, wiggling and shaking things until you do find it.

 

As for the tick, sounds like you already diagnosed that issue.  You can search for "tick of death" or "engine tick" in these forums and find volumes of information about oil pump related solutions.

[Len Dawg]

In regards to ...If it sounds like a Metallic clank,click and its slightly delayed from engine rpm it may be time to increase octane to 92..and or check timing plugs wires cap rotor etc..at low rpms under 3 grand I would say your pinging..

[rdweninger]

Sometimes the clicking sound could be an exhaust leak at the heads. It will go away when the pipes heat up and close the gap. Easy to check at start up, with front wheels up on ramps. Be careful.

[idosubaru]

How loud is this? Like a non car person wouldn't motice, obvious, turns heads, or cover your ears?

 

Exhaust heat shields

Exhaust leak

Cracked fleplate

[Keep it in the Family]

The clank is loud enough the a non car person would notice it at low rpm. But it's definitely not head turning or anything. The ticking makes the engine just seem loud (according to my girlfriend). She didn't hear the ticking itself.... I can though.

 

Today is going to be nice enough to check for loose bolts/components under the hood in the afternoon; I'm going to pull the car up on ramps and look for exhaust leaks now while it's cool enough to see the exhaust easily. And yes, I'll be careful, no need getting crushed today.

 

As far as 92 octane, the engine is worn (low compression), has decently low compression ratio, and I'm at high elevation (above 6200 ft), so I'm thinking its something else. I may check the timing with a timing light though to make sure its not overly advanced.

 

thanks for the ideas everyone