lifter noise questions

[Todd Staples]

I posted something earlier regarding this problem. Now I have some more info. I removed the engine and replaced all the seals, gaskets, rod bearings and rebuilt injectors, checked the OPRV which is the upgraded part, rebuilt oil cooler, replaced water pump and some other stuff. That was about 16K miles ago and the engine has about 156K on it. Has good oil pressure, 4-5 on startup, 4 cruising, and about 2-3 on idle. I use 10W-30 Mobil 1 and it uses about 1 1/2 quarts between 7500 mile changes. Compression check shows 130 across the board on all 4 and the spark plugs are showing a nice clean, brown burn. Never smokes and runs strong. As good as everything looks, I suspect my pressure gauge is reading a little on the low side. I began hearing what I believe to be lifter noise, but at 2000 rpm it quiets down to normal. About the same time the noise began, I experienced an oil leak from the front of the cam housing and after removing the front cam housing cover discovered the front seal was leaking. All of the lifters checked out when I had the engine out resealing the cam housing. I ordered new front cam housing seals and will replace them. Is it possible that the front oil leak would have enough effect on the oil flow that it would cause lifter noise? I guess if I still have noise after replacing, I'm not out anything except a little time and the next step would be to remove the cam housing and inspect the lifters? Any suggestions or has anyone experienced this same symptom?
Thanks,
Todd

[hpservertech]

Might want to go ahead and run some seafoam through the oil. Run it for a bit then do another oil change.

[924Sman]

No, the leak would have to be so significant to cause the lifters to run dry. The lifter bore has a channel in which feeds oil into the lifter port and is sealed for the most part by the bore walls. If this is a fresh rebuild, the lifters can take 45 minutes to build up enough oil pressure to fill the lifters back up. If this is the case let it run for a 1/2 hour or until they quiet down.

Dal

[Schumi]

How would you go about running the car to let the lifters build up? Just a half hour of idling?

[Todd Staples]

Not a rebuild, but did have the engine out, new rod bearings, seals, ect. I have about 16K on the engine since all of that, have had no oil leaks, and the oil pressure is steady and within specs. Just started all at once along with the front cam oil leak. Like I said, rev it up to about 2000 rpm and it lifter noise is gone. I have to replace the front cam seals anyway, so I guess I will do that and see what happens. I guess next thing would to be pull the cam over and check the lifters?

[924Sman]

Schumi....Drive it.

Todd....Get the seal installed then run the engine for a while, you may find it quiets down in short order. The bad seal may not be allowing the oil pressure to build up enough to pump the followers up enough, which makes sense by the 2000 rpm and quiet down, just high enough rpm to get the pressure up for a time, but they should stay quiet once filled.

If you pull the lifters make certain they are kept in order. The followers(lifters) will be used to the cam lobe that it hits. They are offset, each lobe hits the top of the follower in a manner to spin the follower in its bore and cause a wear pattern. If one is not replaced in the same bore the offset will not be the same and cause some issues. It is said to replace all the followers when needed with all new ones for this reason, all have the same flat surface the lobes hit and over time they will wear a pattern like the old ones. Over time the follower tops become concave to a small degree. The bore walls also become patterned to the original followers, another reason to keep them in order.

It takes some time to fill the port in the follower to pump them full of oil. That port is only a couple MM in diameter( very small). They fill by the spring/piston inside the follower pumping up/down along with the oil pressure, as the lobes hit the follower it pushes them down on the valves and returns when the lobe clears the follower top(face) creating a suction which sucks in the oil.

It could be the oil channels on the cam tower are blocked by gasket material/dirt which would impede oil flowing to the lifter ports causing them to not fill up. This is very doubtful however but it is possible. You would see this when the tower is removed and visually see the cam tower gasket and the condition it is in.

Dal

[mattdavis11]

If all of what you said is true, I'm going to be very disappointed. I put my old lifters into a different cam tower with a different cam. I wonder how much time I am borrowing.

It makes less noise now though.

[944Spec_bound]

Originally Posted by 924Sman

Schumi....Drive it.

If you pull the lifters make certain they are kept in order. The followers(lifters) will be used to the cam lobe that it hits. They are offset, each lobe hits the top of the follower in a manner to spin the follower in its bore and cause a wear pattern. If one is not replaced in the same bore the offset will not be the same and cause some issues. It is said to replace all the followers when needed with all new ones for this reason, all have the same flat surface the lobes hit and over time they will wear a pattern like the old ones. Over time the follower tops become concave to a small degree. The bore walls also become patterned to the original followers, another reason to keep them in order.



Dal

Oh, crap.
just replaced my cam tower gasket, started it and have some lifter noise now.
did not keep the lifters in order.
sigh.

[924Sman]

This issue is subject to the amount of wear, some may be ok some not. The more wear there is will dictate which mismatched followers make noise. Eventually they too will take on a new wear pattern. Don't get to worried though they will still work with no issues later except in the worse case they will be too worn out and cause some valve opening issues.

The followers are just like the pistons which are numbered to the cylinders but in time different pistons put in will adapt to the new cylinder wear, just never as good as the OE ones.

So relax, too late now so get out and do laps!

Dal

[Todd Staples]

I replaced the front cam seals and all the lifter noise disappeared. I guess I was losing just enough oil pressure from the front of the cam that it wasn't allowing the lifters to load with oil. Maybe someone will have the same problem someday and this will help.
Todd

[mtccl]

run heavier oil.

Recommend 20w50 and the noise will magically disappear.

[Todd Staples]

I have been running 10W-30 Mobile 1 last couple of years with no lifter problems. I'm convinced that the front cam seal leaking was causing just enough loss of oil pressure that the lifters were not loading up. 10W-30 gives me good oil pressure and I change it at about 6K-7K.

[hpservertech]

Sounds good Todd.

If your up for it, we are going to a GTG this weekend up in St. Louis, your more then welcome to join in. Going to do some decent twisty roads.

[Todd Staples]

I have to work or I would sure try to make it. I plan on being up that way next month. I will try to let you know, maybe we could do lunch or something.
Later,
Todd

[hpservertech]

Let me know man. House is always open.