Oil filter question/knocking when warmed up, 350 buick

Which is one of the main reasons I advocate low lift lobes on flat tappet designs, even with proper zinc levels.

Much higher than .450 and I'd highly recommend roller cams, or just be happy with a milder flat tappet.

(just as a brief side note)

Gary

 

It looks like it is time to start eliminating some things. For starters I would mark my distributor location, remove it and check the up down slack with feeler guages under the drive gear. Remove gear and shim it to a maximum of .010" and press gear back on. If the timing chain is loose, the back lashing at idle may be popping the distributor up and down. Be sure the gear is oriented the same as it was removed, mark the gear and shaft before removing gear.

 

Texasjohn55, I did previously determine that the timing chain is loose, so maybe that indicates something. I had someone turn the crank pulley while watching the rotor, and it took the rotor a long time to move.

Like I mentioned before, I can click the dist. rotor up and down, and when you pull it up it goes up with a double-bump (like ba-bump). Same if you turn the advance springs clockwise (I think, maybe counterclockwise?), does the same double-bump-up.

 

I had the same issue with a 2002 Ford Taurus.......My son fixed it, with a concrete light post.

No one hurt........Taurus totalled.

I don't recommend going that route.

 

I was thinking timing chain too. You can check play thru how much you can turn engine by hand and see when rotor starts to turn or pull fuel pump and look/ feel how loose it it

 

Alec, I was also thinking that since the prev. mentioned timing cover might be the incorrect size, with the wrong size oil filter, etc., maybe the cover is too small and the timing chain is bumping the cover?? If it is the timing chain, could it cause a rhythmic sound similar to a lifter or would it be more random rattling noise?

 

As a side note: With a timing chain that loose you are running retarded valve timing which hurts low end performance. You won't believe how a new timing chain and gearset will WAKE UP that old engine. Be sure to reset your timing as it will be too advanced with a new chain set.

 

The V6 and 350 covers are the same, its the filter/pump cover that's a bit different, but will function the same.

 

Too much end play in the crank will make a similar noise to what it seems like you are experiencing. I had one I could have sworn had a rod knocking and it turned out to be the crank slapping back and forth with too much end play.




Group question about the metric oil filter cover. Is there any advantage to it or any harm in using it instead of the 350 pump cover? I need a new one and not sure what to get. Seems to be a broad price range in them. Insight?


David

 

nothing wrong with using the metric housing but the small filter.grand nats have an adapter available to use a bigger filter. but it looks as though he has right cover.either way if timing chain has enough play it could be hitting the inside of timing cover ,if it has nylon teeth it could have one missing and hitting the metal of the gear. so check chain and go from there.

 

Beat me to it.

Good call. I've seen this too.

Gary

Perhaps with a bit of mileage and wear on the engine, coupled with the use of that smaller filter, the volume (not pressure) isn't quite enough to supply the lifters once the engine warms up and the oil thins out a bit, but would go away above idle because the volume is being restored. This may be the cause of the lifter noise.

This also may explain why the oil pressure is remarkably high for a stock engine at idle. Less volume due to restrictive smaller oil filter would result in higher pressure, at least at the guage. (??)

As mentioned before, this could be end play on the crank. I've seen this before, and it'll knock a couple times then quit, then start knocking again and quit, etc. It's intermittent because the crank is moving forward and backward with its revolutions, and sometimes it moves faster than others, and if it moves fast enough, it'll slap up against the main thrust bearing in the middle (am I remembering this correctly?) to give the 'clunk' sound. While not detrimental, it can't be good for the engine to have this go on continuously for many miles--and certainly not at higher RPMs.

Surely the pistons/rods will get into a slight bind as it's moving around, and could potentially wear out the piston rings, bearings, and put excessive stress on cylinder walls, wrist pins, etc.

Does the knocking remain present throughout the entire RPM range? Does it get louder when the engine decelerates?

Gary

 

Gary, thanks, lots of good possibilities.

It does not make any unusual noises when decelerating, other than the exhaust popping when decerating on the highway, which is prob. carb. related. As for RPM's, it only knocks when at idle and/or low rpm's, as soon as you hit the gas it goes away.

About the end play on the crank thing, is there a way to check that? It's really more of a metallic noise than a clunk though.

Is there any way I can put the larger oil filter on this timing cover?

 

I'm not 100% sure on the differences between the oil pumps, but with the way you're describing it, it sounds like a volume issue that doesn't resolve itself until there's some RPMs to feed the journals.

Get some backup info on this. Wait for others to post here and give their opinions. I wouldn't run it any more until you get more info. Don't want to spin a bearing or anything.

Gary

Edit: Potential scenario: smaller oil orifices in smaller pump/pump cover/filter (or whatever) shows high oil pressure at idle, and oil pressure only goes up to a point then stops building. This seems to me like there's some restriction somewhere which would show high pressure and give a falsch sense of security while the volume was sorely under what it needed to be, and was only restored enough to keep things from making noise at higher RPMs.

You say it's a v6 pump? Maybe they were designed for those smaller block volumes and with the longer v8 journals, would require more oil to circulate (volume), while at the pump, pressure looks fine (actually high) because it's squeezing it through smaller orifices. (??)

I'm not saying this is it, and I'm not a pro on the oiling systems (there's others here who would be way more qualified to speak on this subject than I), but I'm offering something that may be what it is.

If so, I'd be reluctant to run the engine any further until this issue is resolved.

Best wishes

Gary


Hmm. Just reviewed the rest of the posts. Seems the noise from the timing chain/distributor could be from a heavily loaded/stressed oil pump, which would be the case if it was trying to keep up with the volume demand. Ticking and 'grinding' sounds would be low oil volume that is failing to supply the lifters and bearings with adequate oil.

Again, just a potential scenario. Wait for more experienced replies.

Possibly the pump gears are chewing away somewhere. Oil pressure of 40 lbs. at idle when cold would be adequate even with low volume, then it drops to half that when warm, which is still considered 'high' for a stock Buick with mileage and an (obviously) expanding oil pump housing.

I'd definitely be looking to find out more about that oil pump housing.

 

Gary, what should the normal oil pressure at idle be cold and/or after warmed up?
Also, is this an external oil pump, or is it inside the cover (i.e. could it be replaced without removing the timing cover?)

 

v6 and v8 pumps are the same. but a booster plate might help.the filter housing has a surface that the gears ride on and could be scored or damaged. plate will come with gaskets and springs for pressure relief. pump can be removed after taking off filter plate.the one might stick in housing due to varnish/buildup on gear shaft into distributer .i would check your timing chain .if there is enough play in it ,it could be hitting housing as it comes around.pull dist cap then put a ratchet on balancer bolt move it one way until rotor starts to move then mark balancer. then turn balancer the other way until rotor just starts to turn then see how far mark moved. they used a plastic tooth gear from factory and the teeth do break off/wear.
Judgeing only by the pic you posted of oil filter housing and all the red paint you might have the original filter housing and can put on the right filter. the bottom side of filter housing facing the ground is where it will say metric.here is a pic of several timing covers .notice the one that says metric.one you can see the oil pump gears.the black one has a booster plate.

 

Yeppers they're the same pump, gear size and everything

 

Well like I said, I'm not a pro or anything, so we'll just get that out of the way right up front. lol

I'm just playing it cautious and don't want you to harm your engine.

I offered a possible scenario, though I could be wrong of course. (I probably am anyway, but I tend to overthink the hell out of everything, just ask anyone here)

Ideal pressure is 10-15 PSI per 1,000 RPM, though stock untouched factory stuff tends to be way less than that, particularly on worn engines.

It just struck me as odd that's all.

The other guys here have awesome advice and experience too.

Doing nothing else to the engine, maybe just get an adjustable pressure regulator and/or booster plate. Those always help out an old worn pump.

Booster plate is steel and acts like a girdle, preventing the aluminum from expanding too far when it gets hot, which keeps clearances down and oil pressure up.

I was pretty positive the oil pump itself is the same for v6 and v8's, since it's the same housing and same gears. The pump cover that the oil gets pushed through though...I don't know if that's the same or what, but you say the filter is smaller which made be believe there could have been some sort of restriction going on for the v8's needed volume.

If everything's the same as the others suggest, then maybe all it needs is a booster plate and adjustable regulator. Those are good to have regardless, so you wouldn't ever be wasting your money getting those.

Gary


Edit: Duh, didn't see your second question. Yes, external pump. It consists of two gears. One is attached to a longer shaft that goes up and mates to the distributor bottom, which is then turned by the distributor gear by the camshaft. So the distributor drives the oil pump.

The oil pump cover/housing is conveniently located in the front and can be removed without taking the cover off. So the booster plate can be put on without removing anything but the pump housing. Be sure to also get the shimming kit so you can get your tolerances correct.

(Seems Andy's already got you covered on this info)

Very nice pic there Andy, thanks! I'd say there's quite a difference between those two oil pump housings...

Maybe I'm not so far off the mark with the volume theory after all.

 

Looked it up, the spec is 37 psi @ 2400 RPM but not hot idle listed. About 10 is when it starts to be a bad sign... 20 sounds fine.

You said it backfires, any sucking noise at the tailpipe? You may want to fix the carb issue, some motors tick when hot simply from age and are only shut up if tuned 100% and oil level is good.


But that said you got a whole weekend to check stuff out:
:Smarty:The main culprits of hot ticks are:
valve train
water pump
power sterring pump
flywheel
lower end
Exhaust leaks
EGR routing (light rasp)
Lose spark plugs
cams tend to die silently-but they can do it to

Then it's question of is it in time with the engine or 1/4th time or 1/8 or not related to engine speed and how fast.
For example:
1/4th time could be a single piston (every 4th stroke = combustion) while fully in time is a main (every rotation)

I just hope it's not big end and have been trying to point you towards all the other "it could be's," I'm able to think of... but you should spend some time eliminating "horses" before chasing "zebras"

Also, when it taps, turn it off then on and listen for silence > a noise in there would be end play.

Because the 3 guys couldn't find it, assume they are ignorant and start from scratch.:Brow:

 

Almost forgot that, when I shut the eng. off sometimes I get 1 or 2 more taps as it's winding down (in about a split second, no long winding down time)

No sucking sound from the exhaust, only pops when decelerating off the highway.


Unfort., I can't get to it now bec. of the nasty snowy weather over here in NJ, hope to get back to it soon, Maybe I'll take a video as well if I can figure out how to post a video here.



H

 

First, check all the easy items like everyone else has suggested. I have seen this problem where we couldn't find the source of the sound exactly, but seemed mainly in the timing cover area. So we changed all the easy parts. Harmonic balancer, oil pump, water pump, resealed exhaust. Finally tore down the engine, it was a damage cam lobe.