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I'm at wit's end to try and figure out why I'm having an insanely loud tapping coming from the top end of my engine. I did searches for tapping noises and the most common cause I found was HLA's. Well, I just replaced all 12 (just swapped the whole shaft assemblies) from a spare engine and it is still tapping. Next step is to replace the whole head, which I'd rather not do as its a brand new head gasket and that would be a horrible waste...
 

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did you try cleaning your hlas and make sure your getting oil in the head of your engine?

if nothing else do a compression test to check for a bent valve.
 

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The galleries in the head have oil in them, and the HLA's I took out were coated in oil. Also, when running the engine with the valve cover off to check for any damage, oil squirted out. So, that's not an issue. Might have to try the compression test, though.
 

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Have you driven the car around to allow the HLAs to fill up with oil? The tapping is normal on a dry engine and should go away after the engine is warmed up. It's also not out of the question that you may have an HLA which is bad out of the box. You can check for bad HLAs by simply pushing down on the rocker arms. If the rocker arm moves, HLA is bad.
 

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Exhaust manifold gasket leak possibly.

Burnt valve possibly.

Weak or broken valve spring possibly.
 

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I'm at wit's end to try and figure out why I'm having an insanely loud tapping coming from the top end of my engine. I did searches for tapping noises and the most common cause I found was HLA's. Well, I just replaced all 12 (just swapped the whole shaft assemblies) from a spare engine and it is still tapping. Next step is to replace the whole head, which I'd rather not do as its a brand new head gasket and that would be a horrible waste...

Do what magik said and drive around for a little to get the car warmed up.



You also said from a spare engine. Its possible that those HLA's were also bad. There is a FAQ on how to replace just the single hlas instead of all of them.
 

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When was the last time you changed the oil. For me they signal low oil viscosity. The lifters have a hard time maintaining pressure when the oil is as runny as water. Just my two cents.
 

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I use 10-40 synth... make sure it is at operating temp and if it is still tapping than flush the engine oil with a pyrol or other flush then put it a good oil/oil filter and if it is still tapping... Idk
 

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Discussion Starter #10
I took it for a quick spin and when in fifth the tapping isn't as loud, if that means anything.

As for oil, when I changed the head gasket I filled it up with Rotella 15W40 to clean out all the gunk. I just need to pick up an oil filter and then I'll fill it with 5W30.

The main concern I guess I have is, depending on what the problem really is, is it safe to drive the car? I haven't driven the car in about two weeks when the tapping started, for fear of ruining the engine.
 

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When you swapped heads, did you make sure to torque down properly all of the exhaust bolts and the EGR tube? loose bolts on your exhaust housing and a loose EGR pipe fitting can cause the same sounds...
 

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"Quick spin" - can you answer the question - are you getting the engine up to operating temp? The exhaust manifold suggestion is good, too. Are all 6 exhaust manifold bolts intact?

Again, tapping is completely normal on a dry engine if it's not warmed up. This is clearly stated in the Mazda workshop manual.
 

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Discussion Starter #13
I haven't changed the heads yet, but I did properly torque down the head bolts after changing the gasket.

All 6 exhaust manifold bolts are intact and tightened. A leak there could be possible, I shall have to investigate.

The engine originally started tapping after I had been driving for 20 minutes, so it was at operating temperature. However, given that the engine these "new" HLA's came from was sitting in a shed for who knows how long, it could be that they are dry. Tonight after work I'll let the car idle up to operating temps and see what happens...
 

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Discussion Starter #14
So I took it out for a drive again today, got it up to operating temps (the fan came on). I can most certainly say that this isn't an exhaust leak as the vibration can be felt in the gearshift...
 

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I just replaced all 12 of my hla's with brand new ones. I had ticking for awhile, sometimes loud, sometimes quiet, sometimes gone. For a few days it was this way, now it seems to have stopped. Id say keep driving it, otherwise new hla's might be in order for you too.
 

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oh fuck, thats much more than an hla. sounds like a thrown rod or something.

p.s. if you did break a rod, you'll be the first f2 owner to do so i think.
 

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Get your rocker cover off and have a visual check of everything is sight.

As said before could be a broken valve spring or something.

There is no way of knowing until you get that rocker cover off. Takes 5 minutes to do.
 
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