454 vortec lifter noise.

[wtd]

I posted a few weeks ago about my 98 454 making what sounds like lifter noise all of a sudden. I changed the oil and filter even though both only had about 800 miles on them without having any effect on the noise. The oil I drained out looked normal and it looked normal on the dipstick before the drain. Truck just turned over 113,000 miles on it.

My fiancee's father listened to it while I revved the engine up and he said the noise sounded like it was coming from the valve cover on the driver's side. I had him get in the truck and do the same thing while I listened to it and it does sound like lifter noise. It is not a loud tap or tick but sounds like generally loud valve train noise. At idle it sounds almost normal but only gets kind of loud as the RPM's increase.

Last week I changed the thermostat because I had been running a 180 degree one and my gauge was staying pretty low so I decided for the winter I would put a factory 195 degree one back in. I used an AC-Delco one. I have been keeping an eye on the coolant overflow tank and it has gone below the cold mark on the tank twice but I don't know if this is because I had air trapped in the system or because I have an intake coolant leak. The oil does not look like it has coolant in it so if it's leaking, it's not a very big one. I don't know if an internal coolant leak would cause this lifter noise. My 98 5.7L truck had slow intake coolant leaks four times over the years without any lifter noise so I don't know if this would be a cause.

There are no CEL or misfires according to my OBD II scanner. Truck seems to run normally otherwise with plenty of power. I just don't want to ruin the engine by continuing to run it.

So my question is, what are some of the reasons why an engine all of a sudden would develop lifter noise? Thanks,

Wayne

 

[Chris142]

Is it 1 lifter or the whole side?

 

[Ohle_Manezzini]

Could be carbon on valves, since it had run at low temperatures. Try to knock em off.

 

[BrocLuno]

The only way to diagnose this is:

1.) with a mechanics stethoscope,

2.) make sure it is not an exhaust leak which can sound very much like valve train noise. A pin-hole in the manifold to head seal can do it...

3.) pull the valve cover, start it and make sure that all the push rods are spinning the same and all are flowing oil the same. If one is slow, or dry, you have a bad lifter ... Stop. Running any further will kill the cam ...

Now you have to go deeper. Off the intake and pull that lifter. If the face is scored - you loose. If the face is shiny, look at the cam lobe. If it's not showing a wear pattern on one side and no contact on the other, it has gone flat.

Let us know what you find? Running a motor with a failing lifter or cam lobe can spread hardened metal throughout the engine and it's all over...

If it passed all the looking and listening above, it is varnish in a lifter. If all teh push rods were spinning the same speed, your cam is not flat. So it's a matter of getting the lifter working. A full can of Kreen from Kano Labs in each of the next 3 oil changes will clear that up for good

 

[c502cid]

If it's a 454 with stock exhaust manifolds it is an exhaust leak. Take a wrench to all the bolts, I'll bet one is broken. It's a common failure area, much more common then a lifter failing.

 

[AntsinmyEyes]

Originally Posted By: BrocLuno
A full can of Kreen from Kano Labs in each of the next 3 oil changes will clear that up for good

agree with this. had lifter noise on startup which went away after a few hundred miles with half a can of kreen on my truck. been using it periodically ever since.

 

[wtd]

The noise sounds like all of the lifters on that one side. The other side sounds a little noisy but not as bad. The sound is very noticeable inside the cab going down the road. I thought about it being an exhaust leak since I know this is an issue with this engine but nothing is obvious from looking at the exhaust manifold from the top. I will have to get under the truck to see the bottoms. These are the factory exhaust manifolds as far as I know.

All of the exhaust manifold bolts are still showing the heads so I don't think any have broken off and I don't see any movement of the bolts with the engine running. I don't see any carbon buildup along where the manifolds bolt up to the heads on the top side but will have to check the bottom and there are no obvious cracks in the manifolds themselves that I can see.

The bolts do look fairly rusty so trying to remove or tighten them might result in a broken bolt.

I will have to probably wait on pulling the valve cover as we are supposed to get bad weather coming on my days off. I have other vehicles to drive so this one can sit until I can do it.

I have owned this truck since 2007 and bought it with 94,000 miles on it. I changed the oil and filter once a year since then with most years only racking up about 2,000 miles a year. The last year I put about 5,000 miles on the oil change before I changed it.

I replaced the valve cover gaskets not long after I bought the truck and everything under the cover was perfectly clean with no sludge or buildup so I would be surprised if this was from varnish or buildup but who knows. Thanks to everyone on the ideas and suggestions.

Wayne

 

[Phishin]

Originally Posted By: c502cid
If it's a 454 with stock exhaust manifolds it is an exhaust leak. Take a wrench to all the bolts, I'll bet one is broken. It's a common failure area, much more common then a lifter failing.


Agree. Possibly a loose or cracked flywheel perhaps

 

[CT8]

Diagnose the cause of the noise is before you try to repair it.

 

[Trav]

You need a mechanic with a good ear, he will figure it out in no time.

 

[DriveHard]

I would warm the engine up thoroughly, then proceed to drive it 5 to 10 miles at 75% of redline, varying the throttle from part to full to off (Italian tune up). That is after you check the exhaust manifold bolts.

 

[wtd]

I got under the truck and tried to see the underside of the exhaust manifolds but they had a heat shield covering them so I couldn't see anything. I'm just going to have to wait until I have more time to mess with it and the weather gets better.

I may have a cracked flywheel because it does have some other noises that you can hear when you are under the truck. I did use my mechanics stethoscope on the valve covers and you can just hear lifter or rocker noise. There are no sharp ticks or anything. Actually both sides sound about the same.

I also checked to see if my distributor had maybe moved and maybe messed up my timing but it was still solid. Anyway, thanks for the suggestions.

Wayne

 

[wtd]

Well, I think I discovered why I started hearing the engine noise so loudly inside the cab. today when I was looking around again under the hood, I saw that the rubber boot that goes around the steering shaft coming out of the firewall had come completely out of the firewall so that I had a very large hole showing. I have not driven the truck yet to verify if it's quieter inside the cab but I bet it will be. The engine noise did sound like it was coming from under the dash on the driver's side so I don't know why I never checked.

I also don't think I did myself any favors by putting the Citgo semi-synthetic oil in it as the engine sounds more noisy than before. This engine has never been a real quiet one anyway.

Can anyone tell me which 5W-30 non-synthetic oil is on the heavier side?

Wayne