'60 Nailhead-tapit noise

[dplotkin]

I have a 1960 Electra. I got it with 42,000 original miles a year ago. I've put 5,000 miles on it since (I love the car). The motor is powerful, uses no oil, runs cool & starts at the slightest provication of the starter. Lately I'vre noticed some tapit noise has developed, not terrible, but not there before. When I got the car the oil was clean, but I've changed it 3 times since, using Castrol 10W30. What might this be? What oil and/or additive can I run to keep her quiet?

Dan

[JFranklin]

First thing I would do if it concerned me would be to check the tappet clearance. you may spot the culpret.

[Smartin]

Hook up a mechanical pressure guage to see what your pressure is. Does it only happen at idle, or is it apparent with more RPM's?

It could also be a collapsed lifter.

[Guest brh]

Did the noise begin right after or close to an oil and filter change? If so your problem may be as simple as changing the oil filter. You should not need any additives and 10W 30 should be fine. You may want to try a 10W 40 if you are driving in a lot of hot weather. I still think its a bad filter especially if she makes noise only when you start the car. Give us a little more info. When did this start and are a couple of em hung or are all of em making noise.

[NTX5467]

With the low miles on the car, I would think that everything should still be "mechanically" in good shape. Checking the oil pressure (as it has hydraulic lifters) is a good diagnostic "move". Seeing what it is at idle and then up to about 2000rpm should tell if everything is still as it needs to be, but I suspect you'll find everything pretty much "to spec".

Bottom end bearing clearances being too large can cause oil pressure loss at low rpm, but that shouldn't be an issue the your low miles on the motor--I would not think. An oil pressure relief valve spring that might be a little weak MIGHT let the oil pressure be lower than normal, but failure of those springs is (by observation) pretty much unlikely.

Valve guide clearances (being too much) can cause a noise similar to a "loose" valve lifter adjustment, but such loose clearances can also result in the valve seals not doing their job (i.e., increased oil consumption from the "top side" rather than from the "bottom side" of things). As you mention no oil consumption issues, plus the low miles, that's probably not an issue.

A valve lifter not getting fully pumped-up with oil might be an issue, even with correct oil pressure. Using a stethoscope to listen to the internal engine sounds (as it's running) might help isolate where the sound is coming from.

Without taking things apart, about the only way to "treat" the issue would be with an oil additive to clean things up. Viscosity-improver-type additives should NOT be needed as they thicken up the oil and thick oil does not flow to where things might need to be cleaned up. A detergent-type additive would be more appropriate by itself.

In prior times, I've used the Alemite CD-2 oil detergent additive. I'd do an oil change and add one can to the mix. When it got 1 quart low, then I'd add another can. Next time it got to the "ADD" mark or to about 4000 miles, it got changed (a "hot drain" after being driven for about 30 miles or so). This usually was about 4000 miles or so (depending upon which car I was doing it to at the time). I've used it in several cars and it cleaned things up pretty well (as viewed through the oil cap hole). Didn't seem to make any difference in sounds (as there were no unusual sounds, I just wanted things a little cleaner for the car(s) I'd just bought, for a baseline situation), but I suspect it would have cleaned things up to make sure everything was free as it should be.

In earlier times, people added a quart of ATF to the motor oil to get where the normal oil did not get to (to free things up in the valve train, for example). As if the ATF would be a separate entity rather than part of the complete motor oil mix, so it might have put some higher detergency into the oil, but overall viscosity of the oil was not significantly changed. I didn't see that this shadetree "fix" really worked that well, but it was cheap and easy to do at an oil change.

I should mention that NO additive will work "immediately", but will take some time to work as it can. Therefore, patience is needed. The somewhat frequent oil changes you've done are good at getting things flushed out, but not specifically "cleaned out" (although modern oils have more detergent additives in them than when the car was built).

Unless you might have known the viscosity of the oil the prior owner might have used, it might be that they used straight 30 weight motor oil rather than the multi-weight. The single viscosity oils can tend to be more stable in their rated viscosity than a multi-weight might be, yet the multi-weight oils flow much better on initial startup (I suspect). Kind of a mixed bag on this subject . . .

But, as Adam suggested, knowing where the oil pressure is IS highly important on a hydraulic valve lifter engine. I might add that you put the gauge (using the existing oil sending unit hole on the block as the "tap" point) on the engine and check the oil pressure from a COLD START situation rather than starting with the engine warmed up. This way, you can watch the response of the oil pressure as the engine cranks over and then starts (as the pressure builds from "zero"). Seeing how things work might give you an indication of the health of the oil pump. Watching how things might change as the engine warms up and after it gets to fully operational temperature (usually the equivalent of 10 miles of driving, so it might take 30 minutes of idleing to get to about the same situation--oil temperatures do parallel coolant temperatures, BUT at a much slower rate, so heater temperature is not a good gauge of engine oil temperature).

So, check the oil pressure as we've mentioned. Then you might add a high quality oil detergent additive to the oil (not putting the level above "FULL" in the process) and drive the car. After the treatment (as mentioned) and then a fresh oil change, the oil should stay cleaner longer (by my own observations in my cars). It also might be good to put some normal 30 weight oil in it to see if that might help (depending upon the results of the oil pressure test and such). I suspect that if the noise is more when the engine is colder than warmer, it could indicate the light oil viscosity during warmup might be a reason, but I also suspect that "flow" is more important than viscosity in those situations. If the noise goes away with a warm engine (as it might with a mechanical valve lifter motor, with the valve clearances set correctly), then a lifter that's not fully pumping up (it's got it's own piston and such internally to each lifter that must move freely in that respect).

Lots of little gray areas in these theories! Unfortunately, for a limited use vehicle, the miles it will take to make the detergent additive work might be close to a full season's worth of driving, or more. Hopefully things are not too far gone for things to happen more quickly in your case.

Hope this might help,

NTX5467

[Guest edalfa]

My dad had a problem with collapsed lifters on a 61 Lesabre back when it was a new car. In his case, he disassembled the lifters, cleaned them and reinstalled them. He traded the car in 65 and a neighbor bought it. I never heard any tappet noise in the following 10 years that they had it.

Ed

[NTX5467]

The old MOTOR Manuals used to show how to disassemble the hydraulic lifters and such. Pretty simple, as long as you don't lose some of the internal parts. In prior times, though, it was less expensive to try to repair/clean them than purchase new ones. A key advantage of cleaning an existing hydraulic valve lifter is that the particular cam lobe and bottom of the particular valve lifter have "worn-in" together--just put them back with the same cam lobe they came out from, plus some assembly lube on the outside of the lifter so it doesn't go back in "dry". Before you do that, you can also use a pushrod (or similar) to pump up the lifter somewhat prior to installation (being very careful to not force things as you tighten down the rocker arm or rocker arm shaft so that the lifter is slowly collapsed to the operating height of the piston in the lifter body (so that a pushrod is not bent or something else damaged. There might be some more vintage mechanics that might have better advice on the reinstallation/adjustment process.

In more modern times, parts are generally easier to find and less expensive (comparatively) than "back then"--unless you had an "in" source for those things. Therefore, "replace rather than repair" has become the more modern orientation in many cases.

Just some thougths,

NTX5467

[dplotkin]

All you guys have been really helpful. I changed the oil & filter, put in 10W40, and it seems to have gone away. I think she wanted the oil changed. Unlike lesser cars, Buicks are so smooth & quiet that any little noise out of the ordinary stands out.

Dan