Top end clatter / lifter tick?

[Dynomite]

Originally Posted by cmb

Assuming that I do need to replace lifters, can this be done with the engine in the car?

--Colin

No...I would say not.....hard to remove cam covers engine in car and very difficult to set camshaft timing engine in car.
Having said that....it is definitely worth removing one or both cam covers with engine in car to inspect camshafts and lifters for strange wear patterns or damage of any kind. When Cam Covers are removed do NOT get the idea you can start the engine to listen/watch as the Cam Covers are the top bearings for the Camshafts. You can however (with Cam Covers Removed), rotate the crankshaft slowly by hand with a long socket wrench on the Harmonic Balancer Bolt and watch for a sticky lifter or other aberations. All lifters in this case will be/will collapse if left sitting for several hours with lifter compressed since there is no oil pressure to pump them up.

Another idea......remove the serpentine belt and fire the engine up just for a minute or two. That will eliminate any noise from the Alternator, AC Compressor, Belt Tensioner, Power Steering Pump, or Water Pump.

Originally Posted by Jagdpanzer

Video sounds nasty.

I concur.....

Originally Posted by We Gone

Lifter or maybe a bad valve spring?

I concur ......but listening to a cell phone rendition of an engine noise is very very difficult to diagnose.
The LT5 engine does make some normal clicking and clacking noises which often change as the engine warms up or as oil pressure builds up.
Place a stethoscope directly over the suspect lifters on the Camshaft Cover. A Lifter that does not pressure up especially when cold and after not being started for a while would be a major suspect given only three starts since January and the cold temperatures.

Piston slap does not sound like that.

Worst case and unlikely given the minimal starts and low mileage.....You could have dropped a valve (bent a valve) and I would do a Compression Check on ALL cylinders as one of the first and easiest tests.
I would then follow up with a Bore Scope inspection of any suspicious cylinder just to take a look for any damage. My friend and mentor from up North suggested last time he heard that clatter was when a screw had been dropped into a cylinder and I was thinking a dropped/bent valve would be about the same.

Originally Posted by cmb

The last time I started it, I noticed a loud tick from under the passenger's side cam cover, toward the front of the engine. It's definitely a mechanical sound, i.e. not a noisy injector or exhaust leak. I changed the oil and filter and have let the engine run until it's warm, but the noise persists.
--Colin

Does the sound change when the engine is at operating temperature......the answer is yes as I see above.

It also appears the noise could be from the area of the passenger side Camshaft chain/Camshaft Chain Guides/Tensioner?
That would however, be unlikely with such a low mileage engine.

It appears this engine noise started all at once and you are sure the LT5 did not sound like this only a few days ago?
https://drive.google.com/file/d/0B83...ew?usp=sharing

[efnfast]

Welcome aboard. I'm not far from you and can offer help for what it's worth. I've owned mine four 4 years, and am no stellar mechanic. But willing to lend a hand, or an ear. I've heard stories of more than one of these cars sold as junk 'cause the engine was ready to blow, only to find a bad flywheel, single mass flywheel, or bad injectors. -Steve

[efnfast]

Dumb question, how much oil did you put in when you changed the oil?

[Dynomite]

Originally Posted by efnfast

Welcome aboard. I'm not far from you and can offer help for what it's worth. I've owned mine four 4 years, and am no stellar mechanic. But willing to lend a hand, or an ear. I've heard stories of more than one of these cars sold as junk 'cause the engine was ready to blow, only to find a bad flywheel, single mass flywheel, or bad injectors. -Steve

Or "one of these cars" sold because the Transmission was ready to blow or the Clutch/Pressure Plate ready to blow only to find the Clutch Master Cylinder Reservoir empty with a bad Slave/Master Cylinder.

[cmb]

Originally Posted by XfireZ51

Throw some Marvel Mystery oil into oil. Let it run through. See if lifter quiets down.

I forgot to mention that I did add about 1/2 quart of MMO to the fresh oil, and let the engine run for about 15 minutes on the most recent start. No change in the sound.

Originally Posted by Dynomite

It appears this engine noise started all at once and you are sure the LT5 did not sound like this only a few days ago?

I've only started the car three times since I took delivery in early January. I do not remember hearing any unusual noises the first time, although I suppose it could have been present but quieter. The second time (about a week ago), it was as bad as it is now.

Originally Posted by efnfast

Dumb question, how much oil did you put in when you changed the oil?

About 7 1/2 quarts, plus a half quart of MMO, plus maybe 1/2 pint in the oil filter, which I pre-filled before installing. I did not drain the oil cooler. I used inexpensive 10W30, as I never planed to have the car on the road before switching to Amsoil 10W30.

[PhillipsLT5]

Originally Posted by efnfast

Dumb question, how much oil did you put in when you changed the oil?

wait 24 hr to check

[A26B]

I slowed the video down to 50% speed & counted 40 noise events in 6 seconds, which translates to 400/min. A lifter or exhaust leak timing would equate to 800rpm, a normal for a cold start rpm after a few seconds.

Just my thoughts....
Considering your very cold ambient temperatures at start and the metallic sound I am leaning towards a collapsed lifter. Cold temps increase oil viscosity which in turn impedes oil flow. The orfices providing oil to each lifter are very small. At start up, with very cold oil, the engine could run for a short time with minimal oil pressure to the lifter itself. During this time, the lifter could "bleed down" from the pressure exerted during a valve opening sequence..

Watch the Cold Weather video at the bottom of the page & imagine non synthetic oil trying to flow through a pin hole size orfice to the lifter.

https://mobiloil.com/en/article/why-...n-cold-weather


LT5 engines have some unusual characteristics. Putting an engine back together without collapsing the lifters first, can result in valves being held open and no compression until it "bleeds down". So the simplest cure is to be sure all lifter are collapsed first. They will then "pump up" to the proper height for that particular valve stem & cam lobe.

Since the lifter noise started, I am assuming the engine has never actually warmed up.

If possible, you may consider going to a lighter viscosity (0-20), fully synthetic oil. Before draining the 10W30, non-synthetic oil currently in the engine, warm your garage up (or wait for spring) for an extended period to get the engine warm and let it drain for 24hrs before refilling with 0-20 synthetic.

After replacement with the low viscosity synthetic oil, the lifter may "pump up" again and it may not. Keep rpm low & allow engine temps to reach normal, but pay close attention to the noise. If it increases, shut it down.

[XfireZ51]

Originally Posted by cmb

I forgot to mention that I did add about 1/2 quart of MMO to the fresh oil, and let the engine run for about 15 minutes on the most recent start. No change in the sound.



I've only started the car three times since I took delivery in early January. I do not remember hearing any unusual noises the first time, although I suppose it could have been present but quieter. The second time (about a week ago), it was as bad as it is now.


About 7 1/2 quarts, plus a half quart of MMO, plus maybe 1/2 pint in the oil filter, which I pre-filled before installing. I did not drain the oil cooler. I used inexpensive 10W30, as I never planed to have the car on the road before switching to Amsoil 10W30.

I'd throw in the full quart of MMO, let run thru fan kick on. Shut it down. Start it up again once weather gets to 35-40F. I run 10W-40 in my car, but do not start it in winter until temps are at least above freezing and preferably ~40F+.

[LGAFF]

BMWs had a big issue with this....some people found relief with 0-40 oil. With the low miles the lifters might be gummed up.


http://www.rtsauto.com/bmw-e90-valve...ter-ticknoise/

[mike100]

When I helped get Erik's 91 running again after 4 years of storage, it sounded bad and was running on 7 cylinders. After a 4 or 5 mile run down the road (with new oil of course) it was running on 8 and sounded fine. You may need to genuinely get the oil all the way to temp and at some rev to get the higher pressures if the lifters are in need of hydraulic priming.