Golf 2 1.6 TD: Valve Clatter Noise & Fix

Hello,

I'm stuck on a problem and I'm not sure how to proceed. Maybe someone here could offer me some advice?

Problem: My valves (with hydraulic lifters) in the 1.6 turbo diesel engine are making a knocking noise.

Symptoms: The noise is particularly noticeable when the engine is warm and the outside temperature is high, but it's somewhat less frequent or absent for a period of time (around 1000 km) after an oil change.

So far, I've tried:
- 8 new hydrocodone prescriptions - only provided temporary relief.
- thicker oil (15W40 instead of 10W40) - see above.
- new connecting rod bearings (I thought they might be causing the noise) - see above...
- Oil pump tolerances measured. The oil intake strainer in the reservoir is clean.
- Oil pressure measured at the upper pressure switch - approximately 1.5 bar at idle.

Open questions:
1) Could this be related to the injection timing (pump setting)?
Are the Hydros (finally) finished?
3) Can the oil pressure be too high?
4) Should the oil pressure be increased?
5) Is it possible to check the oil channels leading to the lifters for proper flow, other than simply blowing air through them?
6) Can a faulty head gasket cause problems, or can the good oil pressure rule that out?

I would be very grateful for any advice!

Best regards,

Hi,

Symptoms: The noise occurs particularly when the engine is warm and the outside temperature is high, but it is somewhat less frequent or nonexistent for a period of time (approximately ~1000 km) after an oil change.


A (perhaps overly) simple tip:
Do you always make sure that the oil level is at its maximum?
Because that's usually the case after an oil change, and it seems to help - as I understand your sentence above.

Which probably doesn't address the real cause.

7111 wrote:

Problem: My valves (with hydraulic lifters) in the 1.6 turbo diesel are making a rattling noise.

Hi,

Are you sure it's the valves (ruling out fuel injectors, excessive valve timing clearance, and bearing damage ) ? How many kilometers are on the engine? I once had a Passat TD from 1985. It mainly rattled when cold (->usually normal). The engine additive SLICK (very expensive) significantly reduced the engine noise back then.

Hello!

@Markus: Surprisingly, the machine hardly needs any oil, and the oil level is always at its maximum. However, there are people who claim that if the oil level is too high, it can start to foam and cause problems... I might need to drain out about half a liter and check.

@haehnlein: I was also thinking about the injectors, but I think the noise is too loud for that. The mileage is (ahem) around 316,000 km. Do you think it could be the connecting rod bearings? (I don't think the camshaft could make that kind of noise.) I've already tried using a motor additive, but it doesn't help.

Thank you for your input.

Hello,

What do the piston rings and cylinder bores look like?

Do you think something like that could be causing the valve noise? That's a valid question in general, but before I tear everything apart, I'm going to measure the compression.

Best regards,

Hello,

Not the valve clatter, but rattling noises in general.

Hello,

Considering the mileage, it could also be the valve guides in the cylinder head.

Hello Michael 2,

Quote:

Regarding the mileage, it could also be the valve guides in the cylinder head. What do the piston rings and cylinder bores look like?

"In situations like that, I think the oil consumption would probably be quite high."

Best regards,
Albrecht.

Hello,

Not necessarily. There are cases, especially during cold starts, where severe piston slap has occurred. If the rings (particularly the oil scraper ring) are completely worn out, then yes.
High oil consumption typically occurs only with severely worn valve guides and defective shaft seals.

Hello,

Quote:

There are cases where, especially during cold starts, a severe piston slap has occurred

.
That's true, but he writes "especially when the engine is warm."
If the valve guides are already making a rattling noise, the clearance between them should be large enough to cause the shaft seals to wear out prematurely and allow oil to pass through.

Based on the descriptions and symptoms, it's most likely the Hydros, even if they are new!
Here are a few more tips:
In cases of doubt, 15W-40 tends to be thinner than 10W-40, especially at high temperatures (which is the relevant factor here).
Please use 10W-50 oil.
-Was the oil pressure measured when the engine was warm or hot? I suspect that the oil pump may not be delivering the same amount of oil as it did on the first day, and that the pressure regulating valve might not be functioning correctly.
-Sometimes, a low-quality oil filter can be the culprit behind all the problems.

Best regards,
Albrecht.

Hello,

Do you still have the original injectors in? Worn injectors can cause quite a bit of trouble. They cost around €40 at dieselsend.de. However, the problem might disappear after an oil change...

Now, regarding your other questions:

>1) Could this be related to the injection timing (pump setting)?

zu später Förderbeginn macht weicheres Geräusch, Mehrverbrauch und Rauch, zu früher FB macht besseres Startverhalten, senkt den Verbrauch und erhöht die NOx-Emissionen. Aber No clattering...

>2) Are the Hydros (finally) finished?

Everything is possible . You can check them; the Etzold manual states how (I don't remember the exact details, but I've never had that problem despite having driven 460,000 km).

3) Can the oil pressure be too high?

"That's unlikely with these engines, as they already have a very low pressure level. My old 54-horsepower Golf (without a turbo, direct injection, hydraulic lifters, or other oil pressure consumers) had 2 bar of pressure at idle and always 5 bar (maximum) while driving. My 2nd generation diesel, with a new oil pump and connecting rod bearings, only managed 2 bar at 2000 rpm with an oil temperature of 80°C."

>4) Should the oil pressure be increased?

How are you planning to do that? A larger pump? That might address the symptom, but not the root cause. It's actually not really necessary, since the engine doesn't rev that high.

>5) Is it possible to check the oil passages to the valve lifters for proper flow? (Besides simply blowing air through them passively?)

Aktiv durchblasen . Compressed air?

6) Can a faulty head gasket cause problems, or can it be ruled out due to the good oil pressure?

The pressure gauges are directly connected to the pipeline where you measure the pressure, so the pressure line should be clear.

I'm sorry, but I haven't experienced that problem before. We have 4 TDI vehicles, 3 of which have hydro engines, but only the old Passat makes a noise in the morning shortly after starting, until the oil pressure light goes off.


Best regards, Uli.

Hello!

@Uli:

>Do you still have the original injectors in? Worn injectors can cause quite a problem. They cost around 40 euros at dieselsend.de. However, the thing is, it might be gone after an oil change...

I'll give them a try, but I don't believe it because of the oil change argument.

>Oil pressure.

I need to check what pressures occur throughout the entire RPM range, both when the engine is warm and cold.

>Aktiv durchblasen . Compressed air?

It looks like the hydraulic pumps need to be removed, so I'd like to combine that with the next belt replacement...

@Albrecht:

'-15W-40 is more likely to be thinner than 10W-40 at high temperatures (which is the issue here). It's better to use 10W-50 instead.'

Here's an idea: what if the oil cooling system isn't working properly (e.g., the cooler is blocked), the oil is too hot, and therefore too thin? Could that be the problem? What is the normal oil temperature?

-Was the oil pressure measured when the engine was warm or hot? I can imagine that the oil pump might not be delivering the same amount of oil as on the first day, or that the pressure regulating valve might not be functioning correctly.

See above - Oil pressure measurement campaign...

-Sometimes, a low-quality oil filter can be the culprit behind all the problems.

Wow, my oil filters are the cheap ones from the supermarket. I just replace them every time (every 10,000 km). I'll also test that next time.

Thank you everyone, first of all!

Quote:

I have an idea: suppose the oil cooling system isn't working properly (radiator clogged), the oil is too hot and therefore too thin, could that be the problem? What is the normal oil temperature?

Oil temperature when you have an oil/water heat exchanger: >80°C, but it varies greatly depending on driving style.
Pressure readings are meaningless when the oil is cold!

"I'm familiar with that hydro-tapping sound from my old 5-cylinder Passat. It used to rattle like that whenever the engine got a bit warm, although it didn't have an oil cooler."
It could be improved by keeping the oil level close to the maximum, as Markus H. mentioned above.
I once had an issue with an ATU oil filter where it took a very long time for the oil pressure to build up after starting the engine (and there was also a noticeable rattling sound).
I swapped it with another one, and it disappeared again.

Best regards,
Albrecht.

Hello!

The crafting project has been 'slightly' delayed because I was occupied with my partner's mill in the meantime.

Okay, update:

- Oil pressure at the head (when warm) is OK at all engine speeds.
- Timing belt and pulley removed and inspected (it's not time to replace them yet).
- Start date of ESP funding checked -> OK.
- Oil change performed with a slightly more expensive filter.
- Hydrostatic test performed -> both seals on cylinder #2 failed again!
- Oil lines to the hydraulics blown clean > OK.
- Compression checked (32-34 bar everywhere
- Both LIMAs are broken; I have one replacement, but I still need to get the other one.
- The location of the WaPu's storage is uncertain (the noise from the Lima definitely drowns it out...).

The knocking sound is gone for now. Basically, it probably doesn't have anything to do with the bearings, as they only started making noise in the last two months. I suspect that all this trouble might somehow be related to my 6.50 Euro oil filters. I'll wait and see if the noise starts again as the new oil ages. By the way, the oil consumption has been zero since 160,000 km, which means that the oil isn't occasionally being 'rejuvenated' by being topped up with new oil.

By the way, the nozzles still need to be tightened.

Goodbye...