Strange Engine Noise

[Loren R]

08 ST with 80K miles recently started issuing a "ticking" sound on startup, coming from the passenger side. If it was an older engine, I'd say it was an exhaust leak from the exhaust manifold area. But, the ticking stops within about 15-20 seconds, slowly fading away. I'm thinking it's a valve? maybe not getting oil? out of adjustment?

Do these 3V engines require valve adjustments? I don't see anything in my owners manual about it (unless I'm going blind - which is possible..)

 

[GSU4x4]

I hate to be the bearer of bad news but 80k isn't young enough not to have an exhaust manifold leak, and the way you describe it sounded exactly like mine. I hope you have a warranty or you're good with engine repair because its not going to be cheap to fix it.

http://www.explorerforum.com/forums/showthread.php?t=323115

 

[Trac Marks]

+1 for manifold leak, and I am also unaware of needed periodic valve adjustments. Mine also ticks on start-up. I've read too many horror stories of loose manifold nuts and attempting to tighten them leading to a broken stud. Personally, I'm leaving mine alone. 10 seconds of rattle isn't worth risking a $500 shop bill; maybe some day I'll try my luck at tightening. My dad's F150 ticked the same way so I am 95% confident this is what you & I are hearing.

 

[BannonJr]

Could be lash adjusters although the manifold leak is generally the problem.

Rule it out...

In the morning, or whenever it's been sitting, take a long screwdriver or something, stick it to your ear, and the other end on the valve cover.

Have a buddy start it up and you'll hear if it's in the head or not.

Oh, and leave the neck tie out the belts bro! Ha!

 

[Loren R]

I hate to be the bearer of bad news but 80k isn't young enough not to have an exhaust manifold leak, and the way you describe it sounded exactly like mine. I hope you have a warranty or you're good with engine repair because its not going to be cheap to fix it.

http://www.explorerforum.com/forums/showthread.php?t=323115

Thanks, and I don't consider your information to be bad news... Actually, I'm thankful it's something NOT fatal. For now, I'm going to be content to just leave it alone and pay attention to any changes that it's getting worse or causing other problems.
LR

 

[Tech By Trade]

Not a V8 owner here, but would it be possible to pull the manifold off before the stud breaks, take it in and have it planed and then reinstall it on the same studs? From the sounds of it, it isn't the studs fault they break but the manifold warping that causes them to snap.

 

[GSU4x4]

You could fix it prematurely to save some money on trying to get the broken studs out, but I would replace the manifolds and install with new studs just to be safe. Thats what I did both times on my truck.

 

[Loren R]

Not a V8 owner here, but would it be possible to pull the manifold off before the stud breaks, take it in and have it planed and then reinstall it on the same studs? From the sounds of it, it isn't the studs fault they break but the manifold warping that causes them to snap.

In thinking it over, I see no reason to fix it at this time. The "leak" only occurs on startup for 15-20 seconds and stops. That tells me that it is a very small leak, as it stops because the initial start up heat created by the exhaust is swelling the metal and stopping the leak. I would only be greatly concerned if the leak were larger and the sound never stopped at all. That would be a major problem, as the engine could ingest a small blast of cold air when shutting down the engine, and that could warp a valve. That would be a fatal problem in my book.

But my thinking on this is predicated on years past education, meaning high school auto shop and years of self-repairs. And by now (40 years later) most everything I learned has changed, usually drastically. Even if I decided to fix it now, I would probably first consider installing an exhaust gasket rather than having the manifold milled... Again, old thinking, but no reason it wouldn't work as far as I know.

If anyone thinks I'm drinking my bathwater here, please correct me. I'm always open to learning new stuff!!