My car has a noise, what sounds like, a tappet with excessive clearance.
Cam wear or cam follower wear could result in excessive clearance but I've never heard of cam or cam follower wear on the V12.
I checked the valve clearances this week and found the smallest to be 0.011" and the largest was 0.014", which is pretty much on spec.
So, I'm a bit stumped at what could be causing the typical valve train clicking noise. Any suggestions?
Tappet noise
#1 Tappet noise
Best Regards
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
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#2 Re: Tappet noise
So far I 've received two interesting theories:
1) The entire tappet is moving sideways meaning the tappet block is worn allowing sideways movement of the tappet;
2) the tappet is tilting / rocking / see-sawing on the top of the valve stem.
The latter seems quite plausible to me...
1) The entire tappet is moving sideways meaning the tappet block is worn allowing sideways movement of the tappet;
2) the tappet is tilting / rocking / see-sawing on the top of the valve stem.
The latter seems quite plausible to me...
Best Regards
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
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#3 Re: Tappet noise
Stupid question: to check gaps, you pulled off the entire intake system, pipes, etc. and removed tappet block covers? How long did that take? What gaskets did you need for reinstallation?
I'm very curious to hear your outcome. I have tappet noise as well and would eventually like to solve it. Keep us posted.
I'm very curious to hear your outcome. I have tappet noise as well and would eventually like to solve it. Keep us posted.
Bill Gutierrez
1961 OTS - under
1973 OTS - mostly working
1961 OTS - under
1973 OTS - mostly working
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#4 Re: Tappet noise
Bill, it took me half a day remove intake manifolds, tappet covers, check the clearances, re-install everything, re-balance the carbs. I used the starter to turn the crank (too troublesome to use a spanner on the crank pulley.) The only new gaskets I needed was for the tappet covers but to be sure, also have the 12 intake manifold gaskets and the 4 intake manifold to carb manifold gaskets on hand.lundabo wrote: ↑Thu Jan 04, 2018 8:30 amStupid question: to check gaps, you pulled off the entire intake system, pipes, etc. and removed tappet block covers? How long did that take? What gaskets did you need for reinstallation?
I'm very curious to hear your outcome. I have tappet noise as well and would eventually like to solve it. Keep us posted.
The only feasible theory so far is that the (some) tappets are actually rocking / tilting / see-sawing on the valve stems. I recon the only way to fix that is to replace the tappet block and possibly the tappets as well (budget permitting).
Because the clearances were good, I decided that the next owner can sort the tappet noise out once I no longer want the car - and don't expect that to be soon....
Best Regards
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
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#5 Re: Tappet noise
Thanks. Wonder if the tappet guides can be honed and oversized tappets used. Seem strange that they would wear this way.jagwit wrote: ↑Fri Jan 05, 2018 9:45 amBill, it took me half a day remove intake manifolds, tappet covers, check the clearances, re-install everything, re-balance the carbs. I used the starter to turn the crank (too troublesome to use a spanner on the crank pulley.) The only new gaskets I needed was for the tappet covers but to be sure, also have the 12 intake manifold gaskets and the 4 intake manifold to carb manifold gaskets on hand.lundabo wrote: ↑Thu Jan 04, 2018 8:30 amStupid question: to check gaps, you pulled off the entire intake system, pipes, etc. and removed tappet block covers? How long did that take? What gaskets did you need for reinstallation?
I'm very curious to hear your outcome. I have tappet noise as well and would eventually like to solve it. Keep us posted.
The only feasible theory so far is that the (some) tappets are actually rocking / tilting / see-sawing on the valve stems. I recon the only way to fix that is to replace the tappet block and possibly the tappets as well (budget permitting).
Because the clearances were good, I decided that the next owner can sort the tappet noise out once I no longer want the car - and don't expect that to be soon....
Bill Gutierrez
1961 OTS - under
1973 OTS - mostly working
1961 OTS - under
1973 OTS - mostly working
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#6 Re: Tappet noise
The tappet guides are unlikely to have worn. What usually happens ( certainly on the 6 cylinder cars and probably on the V12 as well ) is that the tappets themselves go barrel shaped . They then rock in the guides which is what produces the noise . New tappets is the usual cure
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