Valve Guide Problems: How to Diagnose

I'd be interested to know what symptoms can indicate damaged valve guides. I'm still having problems with my cylinder head.
Mkb AFN 260 Tkm

'Recently, a metallic knocking/clicking sound has been occurring intermittently, both when the engine is cold and warm. However, it disappears from time to time before becoming clearly audible again! My initial thought was that a valve seat or valve guide might be damaged. Otherwise, the vehicle has full power. The fuel injectors are okay.'

Hello Boro!

At what speeds and load conditions do the clicking noises occur?
What about the engine's oil consumption?

Regards,
Alex.

It was especially noticeable at idle! Otherwise, the engine noise is louder!

Oil consumption is approaching zero! I've checked everything again and found that some air is escaping from the injector with the NBF code. I'm going to replace the sealing ring today. Let's see if that fixes it!

Hello Boro!

Do you have any updates on your issue?

Regards,
Alex.

Hello,

Well, not really! My AFN engine rattles like a bag of bolts when it's cold, and when the engine reaches operating temperature, you can hear a loud ticking/clacking sound. I've now purchased a used cylinder head and will have it installed soon, and I'll also have the timing belt replaced at the same time, as it's due. I hope that will fix the problem!

Otherwise, there is no loss of power, and the engine starts immediately, in less than 1 second!

Can someone give me some advice on which gaskets I absolutely need to replace when changing the cylinder head? The cylinder head gasket is obvious, but should I use the thicker, 3-hole gasket? Also, I've decided to replace the camshaft seals and possibly the exhaust manifold gaskets.

Here is my list:

Cylinder head gasket, 1x, 3-hole???
Cylinder head bolts 10xM12x115.
Intake manifold gasket, 1x.
Exhaust manifold gasket, 4 pieces.
Camshaft. 1x
Copper rings ESD 4x

The valve cover gasket is relatively new and will be reused.

Did I forget something?

Has anyone had any experience with these gasket sets from e***?
I mean this one http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=7981100391&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1.

Hello Boro!

Unfortunately, your link is not working (anymore) .

The thickness of the gaskets is not determined by the cylinder head, but by the piston protrusion at top dead center (TDC). Therefore, you should use the same gasket thickness as before.

If you plan to heavily tune the engine, meaning you're going to significantly increase the boost pressure, then the thicker head gasket would be the better choice. Otherwise, it's not necessary.

Are you sure the noises are coming from the valve gear? What steps have you taken to reach that conclusion?

Regards,
Alex.

Hmm.

The link works for me! The article number is 7981100391.

Okay, then I'll go to the car dealership and inquire about the original poem! Is there absolutely no way to tell from the outside??!

Theoretically, it could certainly be something else! I've been experiencing this knocking sound for about 2.5 years. It first appeared during a cold start around 170,000 - 180,000 kilometers. The usual 2-second knock – so I suspected hydraulic lifters. With the increasing mileage, the duration of the knocking sound became longer, so at 213,000 kilometers, I had the lifters replaced. During the replacement, the mechanic mentioned that the camshaft seemed to be slightly worn. (The camshaft seal was also leaking badly).

Here's a slight improvement, as the noises aren't as noticeable in the summer, so I haven't done anything further. Now, the clicking is also clearly audible even when the car is warm. Sometimes it disappears completely. The car is mainly driven on highways, about 600 km per weekend.

Okay, I'm just going to go ahead and have the water pump replaced, and while they're doing that, I'll have the cylinder head replaced as well! I'm getting it done privately, which will keep the costs down. I've read on various AFN forums that people with similar mileage have had their cylinder heads replaced! Maybe I have a small crack in the cylinder head! I'm losing very small amounts of coolant, about half a centimeter in the expansion tank every three months! I already have a new radiator in place.

What else could it possibly be?! The fuel injection pump is sealed and the timings are correct!

Hi.

One possibility is the vacuum pump. This is known to cause such symptoms in AAT or AEL models. You can easily check this by letting the engine idle and, if you hear a clicking sound, repeatedly pressing and releasing the brake pedal. If the clicking stops when you hold the pedal down, it's likely the vacuum pump.

Boro wrote:

Okay, then I'll go to the friendly

and inquire about the original poem! It's not externally recognizable in any way, is it }?

There is no "original" version; all three can be used.
Yes, you can see it from the outside. Remove the cover, roughly behind the dipstick (if I recall correctly), the head gasket protrudes about 2 cm from the head. There are 1-3 holes there.

Okay,

I did the brake test! No change!

It's a two-hole gasket! I found it, thank you!

Nen Werkstattmeister meinte noch das es an einer defekten Hydrostößelführung liegen würde! Wenn der Spalt zu groß wäre würde dieser Stößel das Öl stets verlieren und keine Funktion haben! Was meint you?!

Well, the head will be coming off next week, and I'll keep you updated!