Ticking Noise Only Under Load (91 N/A w/W58)

[plyhard13]

So I have what I think is a strange noise. There is a ticking noise that sounds very much like valve tapping. The weird part is that it only happens under a load. When revving the car in neutral, there is no tapping noise. When the vehicle is in gear and moving (acceleration, deceleration, or coasting) the noise is present. If I'm driving and put the car in neutral, the noise goes away.

I tried putting the rear on stands and running the rear wheels but it doesn't present itself in that situation...only while driving. It's really hard to pinpoint a noise when I have to be driving to replicate it!

Any ideas?

 

[AJ'S 88NA]

How long has it been since the valve lash was checked?

What's your timing at?

What octane are you using?

 

[plyhard13]

I'm planning to check the lash tonight.

I don't have a light gun to check the timing. I guess I should get one.

I run 87 octane. I ran a full tank of 93 with the same noise. The noise seems to be at cam speed...I highly doubt it's detonation.

 

[Poodles]

Exhaust leak?

 

[SC61 MK3]

Sounds like maybe the tranny. Check if it happens both in gear and out, go away by pressing down the clutch?

 

[plyhard13]

It could be an exhaust leak, but I haven't found one. It does go away when I disengage the clutch or put it in neutral. I ruled out a transmission issue because the noise is in sync with the engine regardless of the gear. Maybe I was a bit short-sighted in that assumption?

Regarding the exhaust leak. I think I may have a clogged cat because the car doesn't really want to rev past 4500RPM. I guess that could also be a timing issue. I'll be getting a timing light tomorrow to check it.

 

[plyhard13]

Well, I have one valve shim that is too tight and 9 that are too loose! I guess that may be a source of the problem. I'm off to search for an adjusting tool.

 

[plyhard13]

Well, I replaced all the valve bucket shims. It's still making the ticking noise, but it does seem to rev better. I'm leaning towards really small exhaust leak...or something serious I don't feel like dealing with. I'm not too concerned as this engine only has to last me until early spring when the 1JZ goes in.

 

[hottscennessey]

Might be an EGR cooler leak from the back of the head. Do you hear it at cold start? If it's louder at cold start it is more than likely an exhaust leak (as poodle said). I'd check the EGR Cooler at the back of the head first.

 

[plyhard13]

It is basically the same whether at operating temp or cold. I tried to stick my hand back there to check the EGR cooler but I didn't feel anything loose. I guess I'm not concerned enough to jack up the tranny to be able to see back there. It's just too damn cold...I went through 3 tanks of propane just to do shims! If it is the loose EGR, it's not going to cause any serious problems so it'll just continue to be a mild annoyance for a few months.

 

[Poodles]

Your wiring harness is right above it, as well as your brake lines and coolant lines...yes it will cause issues.

 

[plyhard13]

Good point. I guess next weekend I'll buy another tank of propane and get back to it.

 

[suprarx7nut]

FWIW, my car has an annoying ticking sound that I believe is the speedo cable. Thought it was from the engine cuz it only happens under load. I was paranoid for a while, but kept checking every possible thing and found nothing. I gave up on it, swapped engines a year or two later and the noise was just the same.

Dumb thing with mine though is that I replaced the damn speedo cable and it STILL makes the noise. I think it may actually be my speedo/odometer. My trip odometer went bad 15 years ago (receipt proof from original owner) so I suspect it might be that.

Good luck.

 

[Poodles]

Yep, if the trip meter isn't working, it will click from the gears. Easy to test that one though, disconnect the speedo cable

 

[suprarx7nut]

Yep, if the trip meter isn't working, it will click from the gears. Easy to test that one though, disconnect the speedo cable

Hmm... I'm trying to remember if I got the noise when I had my speedo cable go out. I'm not too worried about it, but I may try that when I redo my needle lighting. At this point I'd rather just tear out the stupid trip odometer...

 

[plyhard13]

That's a good idea. I never thought of that as a possibility. Everything works correctly in my cluster, but it's an easy check so I'll give it a shot when I next have an opportunity.