I have been working on a 444 with a B16 that I recently bought. The engine seems to be in very good shape, runs well, good compression, except there is one strange noise. It's a tapping noise that definetly seems to be coming from the cam/lifter area. First I thought it was the valves sticking or something like that, but after removing the inspection plates I have changed my mind. It is definetly not a bad bearing noise. The old owner mentioned the noise and said something about the timing gears, but I haven't gotten it down that far yet. Any suggestions?

Thanks,

Mark H

My vote is for loose or worn cam retaining plate. Pull all the lifters up till they stick and see if you can duplicate the noise/tapping feel by turning the crank back and forth. Either way pulling the front cover is warranted for a new gear and or retention plate.

Mike!

Got a stethoscope? That can be real helpful in locating noises. If not, you can get similar results with a steel rod... press one end on various parts of the engine, and the other end firmly against your ear with you thumb in between...

My vote is for cam timing gear.

-Matt
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-Matt '70 145s, '65 1800s, '66 122s wagon, others inc. '53 XK120 FHC

It's definetly not a valve noise. I took the rocker arm off and removed the pushrods. With the spark plus out and turning the engine by hand I could still hear/feal the noise down by the cam and lifters with the inspection plates removed. I looked at one of my older service manuals and it said I should be able to remove the lifters and remove the cam etc. but my lifters would not come out from the top. I have to check it out a little more tonight when I get home.

Mark

On a B18/20 over time the bottom edges of the lifters get slightly mushroomed out, making them hard to pull out from the top.

From my experience with various cam problems, they will usually make their worst sounds at very low rpms, and at idle. There the load on the gear isn't constant, as the lifters push the cam backward going up a lobe and forward going back down. This back and forth torque works with any available slack (in the teeth, or working through the tooth angle any fore/aft slack on the cam) to make the noise. When revved up the cam gear gets into a constant pull, and the noise largely subsides.

A rod knock ()while sounding very similar sometimes) is different because it generally will happen at higher rpms, not lower.
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I'm JohnMc, and I approved this message.

Well, there are two choices:
Valve noise, which can be helped by adjusting the valve lash at the rocker
arms, and
A timing gear on the way out. The B16 shares a fiber timing gear with an
illustrious line of engines including the B18, B20 and B30. In fact it might
even be why Volvo eventually went to overhead cams and timing BELTS.
A timing gear knock is a lot like a rod knock except it comes from the lower
front of the engine rather than the oil pan. Every one of the above-cited list
of engines that I have had has wiped out at LEAST one of them. They are fairly
readily available and not too difficult to change. Sometimes they will slip for
a bit and then take hold again and last a while longer, maybe even weeks.
When they completely fail it is like you turned off the key. It'll crank but
it won't hit a lick. The distributor doesn't turn and the valves don't work.
I understand that NAPA makes aluminum timing gears, although I don't know if
the NAPA set's lower gear is compatible with the B16 crank. But a well-
installed new fiber gear will last a LONG time.
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George Downs, Bartlesville, Oklahoma, Central US

George,
When I bought my first Amazon in Amsterdam in 1959 to take with me to Venezuela, I asked the dealer which part was likeliest to fail, so I could take a spare with me. He immediately said "timing gear". You know, I carried the blasted thing in my trunk for 22 years. It turned green with mold, and I never got to use it. The moral of the story: if you want to keep a part from failing, buy a spare and you'll never need it.
Bob S.

In 1967 I had a 1961 122S with the B16 engine. Only my second car after a Triumph Herald coupe. The timing gear failed on the B16. The engine just stopped in traffic. Checked the manual, found the dizzy wasn't turning so popped the timing cover. On this B16, and I assume this applies to all original B16 fibre gears, the metal centre only had a coarse knurling to help hold the fibre when it was bonded on. Unlike the stubby star used in the B18/20 gear it meant that failure was instantaneous. The star will usually give you plenty of noisy notice as it breaks up the fibre gear but the engine will often run fairly quietly at some points of the rev band but sound like big end failure at others. So if this B16 has a gear like mine it doesn't have long to live. That's assuming it's the gear that's making the odd noise.
Cam followers do come out the side but usually have a ridge of cokey muck around the end which stops them coming up further than they have been for the last X thousand miles. If you can't lever them out, carefully, you'll need a home made hook on a slide hammer from the top.
No, this doesn't help the diagnosis, but you might already have found out the problem! Good luck.

I didn't even know they made Amazons in 1959! My first Volvo was a 544, 1960.
So you were in Venezuela from 59-81? I only got there once, in the late 80s,
but it happened to be the time of the International Orchid Show. As the Pres.
of the Panamanian Orchid Society I was pretty well received and quite amazed
at the beauty and variety.. I was in Panama 1971-75 and 1980-98.
In fact I bought my 164 in Panama shortly after I first got there in 71.
Drove it today. It's been through several timing gears and about 245,000
miles since I got it (used).
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George Downs, Bartlesville, Oklahoma, Central US

Actually, 48-81 minus 9.5 years going to school in the U. S. of A. Had a nice collection of varietals which we gathered (before they became protected) in the quebrada below our house and banging our 122S around on the dust, dirt, and mud roads of the interior. Who needs a Jeep if you have a 122 with snow chains, a gunny sack for putting over the engine when you ford rivers, and a bow saw to cut poles to lever youself out with if you still get stuck.
Bob S.

I used the gunny sacks to collect orchid plants.....
I've been places in Panama in my 164 where they had never seen a passenger
car before...., also even more of them in 3 different 122s. I have probably
seen more of Panama's interior than 99% of the Panamanians.
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George Downs, Bartlesville, Oklahoma, Central US