Race Engine Forum UK

oh dear me.

Why has the ticking come back???? cry

After the oil change? Can't be happening to me.
Valvoline 20w/50 to Motul 15w/50 can't have made any difference.
Both same standards and viscosity ratings at 100 degrees.

I'll do another 60 km round run to work tomorrow and see.

Maybe I've got a leaking manifold gasket?

New cams/tappets/bores within specs... doesn't make sense.
Maybe just an air bubble in one of them as I drained the oil..

One thing that has always been present with the car is a kind of rattle on the overun under compression braking.
I had the mechanic in the car over this and said it was due to the design of the exhaust!

Maybe a small end bearings?

revisit my posts on p11/12

on the plus side - at least you know it's not a tappet.

G

1. Valve hitting piston

- Only happens (normally) if the head has been heavily machined (or block) and valve to piston proximity has been radically reduced.
- Bends the valve(s) and the engine misfires at idle although it might feel normal under load.
- When valves are bent compressions drop to a very low level - yours have not

Conclusion: likely not the cause

2. Big end bearing failing
- if very badly damaged can show as low oil pressure when engine is hot
- very high level of gas coming out of the engine breather can show up result from a badly damaged bearing
- can sound like a loose or worn tappet
- there will be a lot of debris in the oil

Conclusion: possible cause: drain the oil with engine hot into a clean container and take a good look

3. Tappet/cam problem
- will be noisy if tappet too loose
- if tappet too tight will wear cam and noise will follow

Conclusion: Possible cause - take the cam covers off and run your finger over the cam lobes. They should have smooth arc. Check the clearances.

Hope that helps some, can't think of anything else at this time. Use of a stethoscope can sometimes pinpoint the place the noise is coming from. A metal rod with one end on the place you're looking and the other against your ear will also work quite well.

Readers, think hard and write only from personal experience OF FAILURES on this one, no reason to cause panic. Brit01 - whatever the cause, just take a deep breath and find-fix it, OK? These things happen.

Yes probably not the tappet anymore - and I get 3-5 psi more with the new cam support with tighter bores.
Ok #2 unlikely as crank felt very good with no worn bearings or high level of gases coming out or very low pressure.

2. Big end bearing failing
- if very badly damaged can show as low oil pressure when engine is hot
- very high level of gas coming out of the engine breather can show up result from a badly damaged bearing
- can sound like a loose or worn tappet
- there will be a lot of debris in the oil

I will use a pipe this time with a funnel to amplify the sound near my ear.

Also tighten the manifold gasket bolts. These are so tricky to access and get a good socket wrench in there.

Small end bearing? Ticking sound possibly, rattling under compression breaking(I could of course have a damaged or bent flange on the manifold that is not sealing properly causing the ticking and rattling sound)?
No knocking for sure.
#3 small end bearing was definitely the most worn of all. This is common with Alfa boxers due to this piston being higher than the other side and slightly less oil reaching it.

p.s I tried removing the spark plug lead but due to the new cap and rotor the spark was so strong the spark noise was so loud it drowned out everything!!! at least I know I have a good voltage there!

I just tried tightening the manifolds bolts - maybe 1/8 turn.
The ticking does appear louder below the car but this could just be due to the echo from the ground.
Also one of the pipes that enter the flange does appear more stained darker than the others possibly indicating leakage.

I have another Alfa fanatic coming around on at the weekend to listen.

Looking on an internet auction site i see this gasket. Does it have a thin compression ring like the head gasket?
The ones I used do not.

it's not a spitting noise from the ex manifold hole is it?

G

Couldn't hear any spitting noise Guy.

But last night after heavy town driving with the fan coming on every 3 minutes I believe the engine was smoothing out.

When there is less noise have to check again tomorrow. Hoping they have blending in now with the new Motul oil.
I'll let you know.

Off to get the oil gear changed now.

Also some nice new idle mixture screws arrived from Italy today. The easy access screws for the Dellortos on the boxers. Nice.

Engine sounded quieter today again. even in a 20 minute traffic jam.

Just changed the oil gear also this afternoon. Came out clean with no particles after almost 3 years.

BUT inspecting the manifolds carefully while in the 'pit', one pipe exiting the flange was stained, maybe some very slight leakage there.

ALSO the left manifold pipe was slightly crushed, obviously been hit from a speed bump or curb at some time!

Looks like more money needs to be spent.

Also I found exh gaskets with a squash ring like head gaskets. Good design IMO. Not all have that.
Have to get some.

Great -ticking stopped!!! Must have been an air bubble after the oil change maybe.
But still manifold needs replacing.

Took it for a hard drive to get it really hot with an Alfa friend and he said it sounded great
All fixed.

Just got to get the other cam box now.

Not the end of the road yet.

Some intermittent ticking is evident espcially when the engine gets hot in hard driving.
mmmmmm

Rather fustrating now but these tappets have to be quiet.

If the gasket was leaking wouldn't the ticking be constant hot or cold?

Maybe OE tappets and a NOS cam box is worth trying on the noisy side.

I'm getting to the point of considering changing to mechanical tappets to avoid these frustrating pressure/hydraulic tappet issues.

Also easier to access (with just a cam lid with 4 screws and a gasket) and easier to adjust with shims.

Rev higher also.

update: no mechanical parts available here so far.

Maybe back to OE tappets from Alfa. INA might have a different valve bleed pressure level due to modern engine clearances?

hi Chris,

I don't think you're having problems with hydraulic tappets as such, or with the fact that you got them from INA. It's a well respected brand and assuming you got the right model (x-checked the part numbers?) and that they are actually made by INA they should be just fine.
Whatever is happening in there (is it really the tappets playing up?) must have a clear cause. That cause will not be the difference in steel hardness nor some percentage of viscosity between two oils that are both labeled 10w50.

Don't give up, find the culprit.

regards
Tom

Thanks Tom.

Yes I am a very persistent/determined person and will get these tappets running quietly if it kills me.

Now the used cam bores for the tappets were just within clearance BUT just. I'm thinking this could be an issue.

Now a new cam box will cost me 250 USD. I have no issue paying this but will be a huge disappointment again if it still ticks.

If I buy the new cam box I will most likely buy 3 OE tappets from the same supplier in Buenos Aires (I have one spare now), and pop them in while it's open.

Now there have been reports of fake products entering Uruguay such as Bosch (I was hit by a fake Bosch cap).

I bought the INA from a VW (made in Brazil though) but the Bosch cap came from Bosch ltd Uruguay also. roll eyes.

Shall I go for the new NOS cam box with new bores? mmmm

thank you

Chris

Thinking about the technical parts of the tappets and how they could differ between brands.

The spring
The lash adjusters

If the OE tappet springs and lash adjusters have different tensions/values compared with INA etc could this not cause issues?

I mean if the OE tappet specs are made specifically to the oil pressure of the pump and clearance of the Alfa bores and I use another brand maybe they don't perform as they should.

Just curious.

INA should work just fine, or the whole world would be stating you shouldn't be using INA in this engine.

Are you sure it's tappets you are hearing? Can't it be slight knocking, or some part of your carburetor that's slightly loose that's noisy? Being careful is one thing, but I've been paranoid about engine noises before. Noises that turned out to be something harmless, or easy to fix things that had nothing to do with what I feared. Exhaust leaks can make strange noises that fool you, get everything you know to be faulty fixed, before taking the engine apart again.

You could take it apart again and re-measure the play in the cam guide. Actually using it may have worn the last bit of debris away that made your measurements just within spec. Personally, I'd be keeping an eye on it and see how it develops before taking it apart yet again.

INA should work just fine, or the whole world would be stating you shouldn't be using INA in this engine

Well this is a grey area and not many Alfa owners have tried aftermarket tappets yet (well the ones on the Alfa forums), some have had major issues with ajusa tappets.
But they ALWAYS recommend OE tappets if you can get them.

Are you sure it's tappets you are hearing? Can't it be slight knocking

I will try to get a better video done but it's not knocking, it's a ticking noise.

Could be that when the new tappets were in the old worn cam bores one or more of them were slightly damaged when they started ticking and now they are not 100% healthy.

And as mentioned it only ticks when at it hottest. Nothing from the carb.



Also if it was coming from the manifold flange I understand that it would tick louder when cold and quieter when hot as the metal expands and closed the gap between the flange and head.
This is not the case.

mmm tricky one but I'm still betting its the used bores. When it gets hot the tappet/s are loosing their pressure.

You could take it apart again and re-measure the play in the cam guide. Actually using it may have worn the last bit of debris away that made your measurements just within spec.

I think this may have happened as the used cam box was very dirty indeed and been sitting around for years. I did my best at cleaning it but as you mentioned maybe the tappet bores just lost 1 or 2 thou as they broke in the last few hundred kms and now are out of tolerance.

I have 4 weeks holidays coming up i Dec at our beach house along the coast with a nice area to work on the car so taking it apart will be a pleasure instead of a dark, dirty and gloomy public garage lot.
wink (summer time here also- southern hemisphere!)

Next week a friend is going to Argentina and can bring back the NOS cam supports and OE tappets.
So got to take swift action or a swift decision - to buy or not to buy.