engine knock on a '74 eldorado 500

[Dan LeBlanc]

ok gotcha.

Looks like i can actually get a set of lifters if i visit at least 4 Autozone stores near me and buy up all they have.

I was going to strip down the existing lifters to see if i could find a bad one, but maybe i should just buy and install a new set?

I can't go further and remove the camshaft right now, thats a bit beyond me in my current setup. I may as well put it back together with a new set of lifters and get it running again, and find someone who can take on the job.

thanks for all the input everyone, i have mixed feelings about this engine and its future :\

Put down the wrenches and step away from the car! 

Why would you want to put new lifters with the old cam the way it is right now?  It ran with the old ones before, it'll run with them again.  No sense in dropping a set of lifters in there without changing the cam in your instance.  It will solve nothing.  If you do have that kind of cash to throw away, I'll send you my address and you can send some to me in an envelope.

If you're farming out the cam job, the lifters will have to be replaced then also, so why buy them twice?  Farm out the job now that it's partially disassembled and be done with it.  Does a cardiac surgeon go in and do a bypass and then leave a hole in the heart so he can go in again later?  Nope! 

[savemy67]

Hello Andrew,

I concur with Greg.  I think you should remove the timing cover and inspect the cam gear.  I enlarged the photo you posted showing the "weird cam wear".  From the photo, the pattern on the lobe looks like a pattern that would be made if the camshaft was "walking" back and forth.  This could account for the knock if the cam was hitting something.

I don't think installing another set of lifters is going to be a worthwhile effort.  Based on how far you have dismantled the engine, what is preventing you from inspecting the cam gear and replacing the camshaft?

The engine looks very clean.  If it turns out that the cam is the issue, you may be OK when the cam is replaced, the timing gears are sorted, and you install the pedestal rocker mounts on the other side.

Respectfully submitted,

Christopher Winter

[Jeff Rosansky CLC #28373]

When we found the cam movement on mine we pulled the distributor and watched the cam gear as we cranked it. Could actually see it moving for and aft at cranking speed.
Jeff

[andysarcade]

here's a video :

https://youtu.be/S5YA2qMoNN8

So, its a good job we checked... the camshaft does indeed move back and forth. :\ I'm sure there's a small amount of acceptable movement in this piece, but probably not by this amount, right?

The camshaft lobes do appear to be lined up with the lifters when the cam is pushed to the front of the engine. I suspect its moving under load or even in normal running which would explain the strange cam wear patterns... doesn't appear to be anything stopping it moving rearward.. ?

["Cadillac Kid" Greg Surfas 15364]

Andrew,
Without beating a dead horse, something is amiss.  It is possible that someone did not install the crank gear correctly and when the chain tightens up it pulls the cam forward.  Possible.  With that much movement you are definitely going to destroy your distributor gear and prob ably the oil pup.  Bite the bullet and fix it before any possibly catastrophic failure leaves you with an even bigger bill.
The front cove  CAN be removed without pulling the engine by someone who knows what to do, and at this point. A new (stock) cam, new lifters, a timing set and distributor gear are the minimum I would put into the car if I intended to keep it.
My "guess" is that it should end up something under a grand and you will have a dependable vehicle.
Greg Surfas

[andysarcade]

Thanks for all the input guys, we are listening and taking heed of the notice. We have eliminated the aftermarket rocker shaft arrangement and are back to stock from here on.

Just as an explanation - originally we had a metallic clank (that was aside from the diesel-like noise) which we suspected lifters.. this is why we put in a set of new lifters just now, in order to eliminate the possibility of a possible stuck plunger or other lifter issue. The cost of a set of new lifters was only $65 and i would rather pay that and eliminate the possibility of a bad one under running conditions being put back in there. We are in diagnosing mode and it makes sense, the removed lifters looked to be in perfect condition, however we couldn't properly check the plunger action or oil flow and have no idea what might have happened to them knowing the car sat for years not doing anything, so a new set is no biggie. We also suspected because of the non-standard rocker shaft setup, they might have been 'special' lifters or may have been damaged or compromised by the different size pushrods, or something else untoward. It was best to eliminate that as a possibility with a new set.

The cam is definitely needing replacement, and why don't we go further you may ask.. well, we are currently doing this in an enclosed car-port tent out in my yard. We have little room as it is and have torn down pretty far to get to this point. My dad is only here for a few more days and so we are out of time to continue, obtaining a new cam on a weekend and the other possible problems we might discover once the timing cover comes off means we would be opening up a further can of worms. (we have already fixed several bad bodges so far with helicoils etc..) To add to that, the car needs to be under its own power to get it out from its parked position, its in a tight spot perpendicular to the gate, and getting it out without power steering and pushing it would be a 10-point turn nightmare. We know the car drives (i've been driving it for the last year with the noise) so getting it back together and handing it off to a garage is my best option for now i think.

The engine is super clean inside, i am hoping that a new camshaft might solve it, but we don't really know the condition of the rear camshaft bearing anyway. I can't dive deeper on this issue, its beyond me, especially without a garage to have it open and laid out everywhere, its too big of a job for me in my little tents with a cart full of tools, and not an oily workshop with everything at hand.

We really appreciate all the advice from everyone, and its good to bounce the results back and forth. We've definitely been in diagnosing mode and discovered lots of things out about this engine, I can confidently go to a rebuilder or likewise now and specifically state whats going on and what definitely needs to be done, and what really doesn't need to be done, with a vastly reduced list of unknowns.

I don't intend driving this around now that i know the state of that camshaft, but a journey to a garage to get it done wouldn't be bad at all.

Now i need to pick your brains about who would be best to take this too for such a job? I'm in Oakland, CA.... thoughts?

[Bob Hoffmann CLC#96]

The only person I can recommend is Greg at Allen's Automotive in Campbell. 408 370-1084
Bob

["Cadillac Kid" Greg Surfas 15364]

Dumb question. Do both belts line up exactly?
1. Damper/water pump/alternator.
2. Damper/AC/power steering
Greg Surfas

[andysarcade]

Dumb question. Do both belts line up exactly?
1. Damper/water pump/alternator.
2. Damper/AC/power steering
Greg Surfas

Well, it doesn't appear either is out of line. There is no undue noise coming from the timing cover area, and none of it moved when we moved the camshaft back and forth...

["Cadillac Kid" Greg Surfas 15364]

Andrew,
Just looking for easy "fixes" for you.  If the crank gear was not set all the way "back" on the crank shaft nose and the hub was not fully seated it could lead to a 1/4 to 1/2" of play in the cam shaft which seems to be what you have. the hub is seated using (hopefully) the factory tool that "pulls it back into place and pushes the crank gear back fully against the crank shafts shoulder.
What would be evident in this case is if the crank pulley belt grooves would be something like 1/4 inch out of alignment (to the front of the car) with the other pulley grooves for the two belts.
It might be worth a shot to double check the alignment.  Not fully seating the crank hub is a common mistake when folks do not use the correct tools to re-install them.
Good luck
Greg Surfas

[chrisntam]

You're in good hands here as far as mechanical advice.

I say a giant kudos to you for posting the ultra clear pics and videos that give the smart ones (they know who they are!) here a clear picture about what is going on.

chris.

[andysarcade]

Chris - thanks for the words of encouragement

Ok, todays update :

- engine totally put back together now. Discovered another couple of minor issues which we resolved, untrapped a vacuum hose, re-tapped AC compressor mounts, sorted out a bodged install of hoses at rear of AC compressor, fixed some bad wiring connectors. (AC compressor is a remanufactured, but someone bodged putting it back in, not done well.)

- ran the engine with rocker covers off, manually oiling rockers until oil came through pushrods... it took a scary long time for the oil to push up through the push rods, but it eventually made it, we're assuming the lifters were taking their time to prime up. Overall valvetrain noise sounds much improved now with stock rockers/pedestals on both sides.
- sealed up rocker covers and put everything back in and went for a test drive.

test drive :
- throttle response is better, overall noise is better.. The specific clanking is gone (the main point of this thread to start with) but the overall diesel-engine like noise remains. We suspect there may have been a lifter issue, possibly a bad one, or possibly a bad interaction with the mongrel buick? rocker setup. Either way, that whole system is refreshed now to stock.

Assessment :
- The new set of lifters, and good used set of rockers/pedestals/push rods has quietened the top-end down a lot, it sounds a lot better, but the 'diesel engine' like noise is still there because of that walking camshaft.
- Found a bad join in exhaust pipes on passenger side probably causing the mild exhaust blowing noise - will fix this tomorrow)

I'm going to get the camshaft replaced at a shop, but have them really inspect bearings and such to discover why it moves, i wont be taking it on any pleasure drives if i can help it for now...

I'll re-visit this thread again probably when the camshaft job is done!

Thankyou all for your guuidance!

[The Tassie Devil(le)]

I am late coming in on the latest pictures of the engine, and looking at the picture of the Cam/lifter relationship, I see nothing wrong here.   The Lifters are purposely set off to one side so that they will rotate as they go up and down.   Without this feature, they would not last very long.

Pictured is the internals of my '72 engine, and looking closely, there is a large amount of offset.

The camshaft is held in position by the plate behind the cam gear.

Plus, the cam lobes are ground with a slight taper which has the intention to keep the cam back in the block, and working on the flange face and the front of the block.   The cam plate is there to simply stop the cam from moving forward.

Bruce.

["Cadillac Kid" Greg Surfas 15364]

G'day Bruce.
Look at the previous pictures.  The lifters are about 1/2 off the cam lobes and the OP says the cam moves back and forth quite a bit.
Greg Surfas

[The Tassie Devil(le)]

Looking at my pictures show the lifters are way off the lobe line, but the cam moving forwards and backwards sounds like the Cam Plate is not there.

This picture really shows the lifter/lobe alignment.

Bruce.

["Cadillac Kid" Greg Surfas 15364]

What cam plate?
Greg Surfas

[The Tassie Devil(le)]

My bad.    I was getting engines mixed up.   I was thinking of the FE Ford engines.   I was getting the two indestructible engine series mixed up.

Forget what I said about a Cam Plate.

Bruce.  

[andysarcade]

so, the photos we took do make it look like the cam lobes go off the side of the lifters, in reality they in fact don't. The cam just moves back and forth about a 5/16" (approx) on the face of the lifters. There are no wear patterns on the bottom of the lifters, they are nice and flat. There is the wear pattern on the cam shaft itself though.

tassie : thanks for the pics! yours looks like it has similar wear on the backside of the cam to mine, what do the lobes look like on yours, can you get a pic or any wear on there?

[The Tassie Devil(le)]

Andrew,

This lot of pictures are of a cam that I replaced out of a '71 that had suffered overheating and had some bad lobes, and had been previously messed up with having a 120 CC head on one side, and a 75 CC head on the other.

It was replaced with a mild cam from MTS.

Bruce.

[The Tassie Devil(le)]

Andrew,

This last lot are out of a '74 that I now have in my '72, and I replaced it simply because I was installing a higher performance cam, and didn't want a possibly lethargic fully pollution cam.

I didn't get more pictures as I was hung up contorting myself to get these as you can see from the overall picture.   They were, and still are on the bottom shelf, behind the angled carby.

Bruce.

PS.   If you need better pictures, I will get them.