[DB7 Vantage Dubai]

Hi All again,

I have had a hard time exchanging wheel bearings, radiators, cooling pipes, tank and more expensive the whole Diff.. After this long period without moving I had a sort of valve ticking noise when i started the car. Not from the bottum but from the top of the engine. We changed the valve adjusters/ also called lashers I think and checked rockers and everything else looked well. Changed with new 5-50 Mobile oil and filter and still ticking noise. Some says it can be air in the oil after still stand and the cure is to drive it fresh with 3500 to 4500rpm in gear over 50miles and with load to get the air out, does it seeem correct to anyone? Has any had the same experience with ticking noise? Lovely noise and had then to change coil packs, sparks, gaskets and whole engine harness loom- lovely job..
I listen to all ideas. Thanks again.

 

[Squid]

It could be one or more Injectors.

Primarily I would have suggested the Cam followers (buckets, Lashes etc)

These are self adjusting but can stick and thus make noise, but as you have changed these along with most other items it really only leaves you with the fuel rails.

Check the Injectors, if possible clean them off the car to protect the cats or possibly have them refurbished.

It might also be a Vacuum leak somewhere affecting the EGR or fuel pressure regulators, again all close to the top of the engine.

Have you tried to use a Stethoscope? Or basically a large flat head screwdriver, about 2ft long, press the screwdriver blade against the top of the engine and then place your ear on the handle.

You should be able to hear all the internal noises very well and by moving around the engine you should be able to pin point the location the noise is coming from.

I'd try both head covers front, middle and rear. Inlet manifolds, throttle bodies, EGR valves, injectors, pressure regs and thermostat housing etc..

My GT sometimes has a top end tap which comes and goes and for mine I suspect a cam follower to be sticking, but only about 10% of the time so it's not a great concern.


The other thing is a possible pinking (Pre-ignition knocking).. might be worth trying fresh fuel.

Hope this helps.

 

[DB7 Vantage Dubai]

HI Squid, I see your name on many post, great to have such a person on this forum. Thanks a lot for a very well explained reply and it certanly give me a few options but also more to dig into.. I finally found the pins and connectors for the oil packs and it will be done coming days. I am tempted to put it all together and try with new fuel and then fresh driving to see if it could be air in the system that make the noise. I will try with s stethoscope, I used on on ships engines, an old trick but it works so why not on a car engine- good point! What is strange is, no noise not a cold engine and oil but comes after 10km when oil gets warmer and warmer. Should there be any different from Mobile 5-50 oil and Duckhams.. Thanks a lot for support.

 

[DARJAC]

As Squid says. Likely hydraulic cam followers sticking.
Happens when a long period of drain down occurs.
Happens with S62 4.9 V8 //M engines.
Used to happen with my RS Cosworths as well !

Would exclude knock / det for now, but run car lightly & up to operating temp.
If issue continues, run on rolling road to see if fuelling is ok. Knock can be
picked up under load, on fuelling & by listening to engine by mic earphones
with an eyelet attached to the intake runner , by removing a fastener &
reattaching. Det or knock is easier to hear from the intake side.

Cheers

 

[Squid]

Inlet Gaskets

Just a thought.

The inlet manifold Gaskets on the V12's are very robust and rather well engineered.

Almost to the point where re-use would be fine without any problems.

Being based on a Plastic Form wafer and inset with Neoprene Rubber seals and locating dowels.. were these ever (remotely) designed to be re-used over a certain lifespan?

I replaced mine when I did the plugs and coils and they are perfect, nothing wrong with them at all. I was going to bin them but thought, why? I will keep them as spares. (just in case)

Also an Independent service agent for AM has also stated having changed hundreds of them they always seem perfectly fine.

So was the engines original design allowing for this, since the plugs and coils are so buried, and do Aston state to change them as a matter of course because it's good business sense for the profits?

A very interesting notion I might add ;-)

Phil. (Squid)

 

[DB7 Vantage Dubai]

Hi again, thanks a lot for your throughts and effort. I picked the car up with new wire loum and running smooth. Changed petrol and went on a fast trip with high rpm as good as the Dubai roads can offer. Still ticking. Speaking to a few special garages they do not think it is the injectors as it would tick all the time and not only when it gets warm. They all find it strange that the enigne is running normal with no noise when it is cold. As soon as it warmes up, ticking. I will later this Month have a garage to look at the valve adjusters again and maybe adjust the correct distance, could be camshaft worn.. After checking that I will check the vacuum EGR as suggested.
A reply to the gasket issue from Squid, true many garages said I should change them every time I am open and closing it these months but still they are good and tight. I manage to find the place that have got all the pins and connectors an Aston might need.. Post it in the other.
Cheers. TB

 

[Squid]

Could it be the Exhaust Manifolds?

That would certainly fit the criteria of being quiet when cold and ticking when hot.

Could be a very small leak but enough to be heard.

You could use a length of tubing placed near your ear and then offer the open end up down by the manifolds and work it all around listening to see if the noise get's louder around a certain area.

Have you tried the Stethoscope method for the mechanical noises yet?

Screwdriver or a correct tool to amplify internal noises and narrow a possible mechanical fault down.

Good news on the gaskets too.. I do think they are full re-usable so long as they are intact and not damaged or worn in any way.

 

[altawashm]

Did u check the Engine Belt?? (stupid Q & A)

 

[Squid]

Ticking Noises

Hello,

Did you ever get to the bottom of the noise source?

Mine is still ticking also and when I applied an earpiece to the engine to narrow it down there was no noise from the head covers at all and the only real noise was from the injector rails. Those injectors sure get noisy.

My noise got a little louder after I cleaned the fuel system, so I am now looking at my injectors in more detail.

 

[DB7 Vantage Dubai]

Top end ticking..

Hi, well I have had many people listening to it and it actuaaly went to a little forum at AM Dubai where some Middle East technicians had an open ear. They think it is the valves lose in the valve guides and the cylinder heads need to be overhauled . . uff it will hurt to pay. I am just afraid that we will do the big job and then we start and dig-dig-dig. I did a few videos of it. If you google or you tube name familycamels there should be two videos.
now we have changed the tappets and rocker arms - still ticking. We tried engine flush, top end treatment and different oil - still ticking. I wonder if it could be injector too but if you hear the video, it sounds like tappets or lifters. Mine is quiet when it is cold but as the oil and engine heats up the ticking starts. is that the same as yours? AM in UK think there might be a bushes we can exchange in the guides but not sure. it does take a bit of the pleasure I must admit..

 

[Squid]

Hello again,

Just listened to your two videos.

YES! the same ticking noise.

Cold, no noise.

Warm starts to become audible.

Hot, sounds like a distinct tap!


To me it really sounds like a cam follower that needs adjusting, however these cars use lashes with shims, so if your shims are good and the clearances are correct, it has to be the lashes!

Or from how it sounds ONLY ONE!! but then can this be common place for a single lash to stick on more than one engine?

Remember that these engines are only just coming to age now, so maybe more will exhibit this type of fault.

My engine has done just over 50k miles, was quiet as a mouse a couple of years ago and the past 15 months this tap has slowly got louder.

Mine is not quite as loud as your's but I imagine it will increase with time.

Do you ever get any signs of hesitation when driving, as though suddenly someone turns off the fuel for a split second or more?

I have used an earpiece around my engine and cannot locate the exact source point. The heads and top end all seem very quite and I can hear the valve train running away nicely.

The noise on mine seems to emit form around the fuel rails, so I still suspect injectors with the valve lashes coming a close second.

I wonder if it could be the fuel rail pressure regulator?????

This is a vacuum driven diaphram that could be noise as it will have a spring in there and a metal shaft, no doubt.

I don't think it will be directly related to the valves themselves, such as seats, guides, etc,, it "MIGHT" be a valve spring however.. but without a stripdown and test on all parts it's a shot in the dark.


On the second video.. I thought the sound got louder towards the front of the bank closest to you.
Possibly the second cylinder of that bank from the front.

Maybe worthwhile, disconnecting a couple of the injectors to see if the noise stops?

The engine will run with approx 6 of the cylinders out, so it might be a quick test to disconnect each cylinder in turn to see of the noise changes / stops or get's louder when a particular injector is disabled.

If any thing it might narrow down the search.

My car lives outside and it's either very wet outside now or freezing, so I get little time to play over our winter months. But if I get chance I will try to do the injector de-plug when mines being noisy.


Good luck,, I'm sure between us we can figure this out ;-)

 

[Squid]

Replied to your PM.

Together we will get this fixed!!

At this point in time my money is on the Valve Lashes.

But could even be a broken valve spring. (last half of coil, perhaps)

See diagram below::

1: Hydraulic Valve Lash
2: Roller Rocker

 

[DB7 Vantage Dubai]

Hi,
Thanks for your thought and we will solve it. I have this weekend opened the right bank again and taken the tappets up. You and others said it sounded as its from the right side. One of these evening we will check each lubrication channel if one should be blocked and not give the reguired oilpressure to the tappets. It could easily be a little gasket bit or something that has gone up and block the channel- not sure but I will know more later this week as I have an experienced friend to come and view it. Funny you mention this with the spring as I think I have two of the plates that holds the springs that are broken but I will let you know. Imagine how nice this engine will be with no ticking..

 

[Squid]

Mine was a little louder the last couple times I have used the car, but I have been a hermit lately and not gone out hardly, once a week!!!

So with a longer drain down time and the way the noise changes from time to time I would say it HAS to be a valve lash !!!

Best thing to do I think is to simply identify the proximity and then exchange all lashes across 3 cylinders focusing on the most obvious suspect.

That's 12 lashes required but should solve the problem. Once complete you can conduct a compression test on them all and see which one is bad. Maybe worthwhile noting down cylinders and positions, in case of future problems, as it might re-occur in the same place.

 

[DB7 Vantage Dubai]

Hi, Have had the right bank open again last week and checked if it could be something easy as clogged lubrication channel but noup. Now that I had it open I changed 24 lashes in that side so I have seen it with my own eyes. Left side were changed last year by a garage so you never know if they did it or not.. Any way this time I tried another oil Castrol Edge 10-60w instead of the original Mobile 0-40. Along I went and slowly it came back that blo.. noise but much much less noise than with the Mobile oil. My noise is from right side and surely a lasher, thing is to find what is causing it to tick.. Using this oil it also shows it is a lubrication issue and I am now hunting for a 70w oil. Lucas has done a racing 70w. It will not repair the problem but maybe make me enjoy driving the thing. Have you heard of Lucas 70 or any other oil that are thicker than 60w with high temperature?

 

[DARJAC]

You're problem is not the oil & messing with viscosities beyond 10w/60 are not advised.
I was a member of powertrain development when the engines on both the V8 & the Duratec V12 underwent significant engine lubrication, ringpack & valvetrain development
changes.
Like or loath the 0w/40, it supported the development cars all through durability sign off.
Something mechanical / hydraulic in the valve train has failed or fatigued.
A stethoscope can help isolate the noise to an area.
I take it that all the Hc Co emission values & other engine smooth running aspects are ok ?

Cheers

 

[Squid]

DARJAC,

Mine also has the same noise, not as loud but it's there.

I've used a kind of stethoscope to narrow it down and it can only be heard from around the injector rails. not through the head cover top or inlet manifolds etc.

It also taps slower than RPM, approx 1/4 rpm speed, so this would tie in with valve train gear as opposed to crank.

Worst case scenario is a small end on just one piston ????

But for this fault to appear on two totally un-connected cars, same sound, same place etc.. either a fantastic coincidence or possibly signs of something to come on all engines as they age.

Mine has done over 50k miles.


My pattern of thought now is focussing on perhaps it is indeed a Valve Lash making the noise,, but perhaps the guide one fits into, (the hole within the head) has become worn so the lash is actually moving about on a horizontal axis to give the tapping noise..?


To my ear, it can only be one of a few things...

Camshaft lobe wear.
Valve Spring Broken
Valve Stem warped (enough so through heating allows it to stick a little)
Lash hydraulics faulty
Lash seating/guide worn allowing lateral movement.

Failing those then Small end / gudgeon pin fault.


Any other ideas?

 

[DARJAC]

Tend to agree with where you are now & prognosis.
The tapping noise is likely to be hydraulic lifters.

But...have your injectors been removed & put on a test rig to see how they perform ?
It can make a marked improvement in performance & may eliminate one aspect.

I doubt its little ends as the tend to resonate in the mid range with detectable noise heard
back in the intake runners. Ultimately another pair of experienced ears is always worth
checking this sort of fault. We check each others diagnosis in the workshop.

Have you tried an aggressive engine flush or an engine flush oil change in a can ?
I'm personally doubtful of this having an effect, but anything is worth a try prior to a strip
down !

Cheers
DARJAC

 

[Squid]

Have performed an aggressive flush last August.

Used Forte engine flush and added the required amount I then ran the car for almost 60 miles.

Towards the end the tap did seem to reduce slightly, and upon changing the oil and filter I thought I was onto a winner, until it slowly came back.

It goes through phases of being less noticeable so obviously not a completely worn part that is a constant source of the tap.

When probing the source of the noise, the inlet tracts are quiet as a mouse, same for the actual head covers and all around the accessible areas on top of the head.

The only noisy part I can detect are the injector rails, though on the rail there is a lot of chatter due to the injectors. However the distinctive tap can be heard through here.

I tend to agree with the small end, I was shooting in the dark with possible worst case scenarios, but there is no increase in tap loudness or pitch when accelerating etc.. it just becomes faster with engine rpm.

It can mainly be heard on tick over as the other engine noises and exhaust is much quieter therefore the tap is more prominent.

I did use a fuel system cleaner at some point, before the flush.. and if anything from memory I think it made the tap louder,. hence why in previous postings on here I focused on the injectors more.

I think the next stage is to have a few injectors swapped out. As it seems to be coming from a specific area, I see no need to change out all 12, just 3 or 4 to ensure the rogue is caught.

But could an injector really sound like a cam lobe/rocker is severely worn?

And... what if this begins to happen to more and more of these engines over time? Could this be classed as a manufacturing fault? Engine testing aside, there is no real substitute for real life use and time! Thinking here about the thousands upon thousands of heat-up and cool-down cycles and unpredictable engine loading etc..

 

[Squid]

Well tonight, myself and a few friends had a poke under my bonnet.

I had mentioned the tap and offered to demonstrate the noise, as the engine was relatively still warm from a recent drive I was confident the tap would be there.

Started it up.. Nothing,, quiet. So revved it quite well and still nothing.

So I removed the center cover over the injector rails and started to poke about....

As I pressed down on the bunch of looms the tap started. When I moved them again it stopped.

And then I found as sweet spot where pressing made it tap, not pressing and the tap ceased.

We then started to unplug each injector around where the noise came from, and it seemed to be the front injector, when unplugged we couldn't get the tap at all.

So this really does seem like an injector problem.

So I set off home,, 90% of the way home no tap. then close to home the tap came back quite loud.

Obviously by this time the engine was rather hot as I had been using the throttle quite a lot.

Once back on my driveway I lifted the bonnet, removed the cover and started to prod the looms, hoping to make the now very distinct tap disappear... it did not!

After a few minutes of unplugging and re-plugging the injectors the noise did reduce quite a lot as to be almost gone, but not quite.

So at this time my focus is 100% back to the center tunnel and I will be removing both injector rails and checking all the connections and cables for continuity and soaking the injectors in some type of cleaner (carb cleaner perhaps) I will make a DIY loom for an injector and work each one with power whilst submerged in cleaner to ensure it's taken into the inner workings...

I think I have a full set of plastic clips for the injectors which I never used when I changed the coils, so I may take this opportunity to fit them and check all the terminals.

I will mark each injector as to where it came from and when reassembling I will purposely swap the suspects around with none suspected ones and see if the noise moves positions, should it come back.

Fingers Crossed !!!