Nozzles vs. Hydrojets: Noise Comparison

Hi,

With 202,000 kilometers on the odometer, my 1Z is definitely no longer a new car.

Especially when it's cold, it tends to make a rattling noise – most likely coming from the valves.

This assumption is reinforced by the fact that it seems to be related to the oil level.
Even at a moderate level, there is noticeably more noise than when it's set to full.

What bothers me is that it rattles much more under load than when it's unloaded.
That kind of behavior sounds more like a Duesenberg rumble.

Since neither option is cheap, I'd like to clarify in advance what a trade would entail.

Could it be that new hydraulic components are still making noise because the old ones weren't just failing due to pressure issues, but also because the seating of the hydraulics was already slightly enlarged, meaning they weren't being guided as precisely?

If something like that is considered normal for products costing over €200, then I can probably skip the Hydro treatment – especially since I don't want to install cheap parts from the internet.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

Hello, I don't think the hydraulic lifters are more or less noisy depending on the load; they don't receive more or less pressure based on the load, but rather from the engine speed and oil pressure. It's more likely that the valves are rattling in their seats, which is considered "normal" at this mileage for a .

"So long."

I'm sorry, I don't understand the question. Could you please rephrase it?

How can a valve flutter against its seat if the hydraulic system above it is precisely controlling it?

Or do you mean that they are rattling in the leading?


Normally, when people say "the lifters are clattering," they mean that the valves can hit their seats due to soft hydraulic lifters.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

Do you know how a valve or a hydraulic cylinder works?

When the valve is closed, meaning it's not actuated, it rests on its seat to seal off the combustion chamber. The hydraulic lifters are only there to compensate for any play between the camshaft and the valve when the valve is being opened or closed (roughly speaking).

Hi Martin,

It's probably clear that as the mileage increases, not only do the hydraulic lifters themselves wear out, but also the 'seat' they rest in becomes worn. The valve guides also naturally wear down, which can contribute to valve tilting and potentially cause valve noise. Consequently, changing the hydraulic lifters may only provide limited improvement in some cases. Furthermore, it's extremely unusual for hydraulic lifters to rattle above a certain engine speed and also be load-dependent.

I'm leaning more towards the nozzles.
You know that one of my nozzles is about to fail (still due to lack of time ).
I only noticed by chance, while using VAG-COM, that the fourth injector was outside of its tolerance range with a value of +3.79. Now, this injector occasionally rattles, and it's dependent on engine speed and load (which is understandable). This rattling/ticking sound is very easily confused with hydraulic lifter noise, as they have similar rhythms and sound patterns.
Using the screwdriver listening test, I was able to clearly identify the nozzle as the culprit. A new set of nozzles has been ready for weeks. We also have a nozzle testing and adjustment device, but we just haven't had the time .

As I mentioned, with my 150,000 km (approximately 93,000 miles), one of the injectors definitely failed. And with your over 200,000 km (approximately 124,000 miles), they are all likely not in the best condition anymore. As Rainer described in another thread, the injectors should be checked by 150,000 km and replaced by 200,000 km at the latest. I am convinced that my old injectors will confirm this after being replaced.

Best regards, Georg.

@mserge

Yes, I think I understand how both parts work.
http://www.vw-club-filder-rems.de/wissenswertes/hydrostoessel/hydrostoessel.htm


When the hydro becomes soft, the valve is not braked during movement towards the seat because it doesn't have to follow the curved path of the cam. It can slam into the seat with momentum.
Exactly like having plates that are too small to fit properly in the cup holders.

And this latch rattles.

Here's an addendum:
(The diesel engine auction was a while ago, here are some comments about it.)

Replacing the injectors in my TDI was definitely worth it!
When I inspected the old nozzles, I was horrified to discover...
The nozzle assemblies were completely clogged with carbon deposits, and some of the nozzle holes were completely blocked.

1. Cylinder: Poor mold filling, 2 voids.
Cylinder 2: Poor casting quality, with two holes.
Cylinder 3: Poor spray pattern, with one hole blocked.
Cylinder 4: Poor casting quality, with 4 holes.

Considering that the nozzles were completely useless, the tractor started and ran surprisingly well.
The fourth injector was outside the tolerance range when checked with VAG-COM, but I didn't expect it to be that bad...

After replacing the injectors, I was finally able to achieve a fuel consumption of around 5.2 liters per 100 kilometers again.
I could barely get less than 6.5 liters per 100 kilometers with the old car.

Therefore, I can wholeheartedly confirm Rainer's statements regarding nozzle lifespan and reduced consumption after the nozzle replacement!

Best regards, Georg.