Clutch jerks when starting, especially in warm weather (A4 Avant AFN)

Hello fellow enthusiasts,

A search for 'clutch jerks' in online forums reveals many entries that suggest genuine clutch or dual-mass flywheel (DMF) problems.

'I've been experiencing this jerking/shuddering for years, but it only happens when the engine and transmission are REALLY warm (after a minimum of 200 km of driving on the highway).'
So, while it's quite unpleasant, it doesn't happen to me very often.

However, now my car is parked outside in an outdoor temperature of 36°C (but the engine is still cold), and lo and behold: The whole vehicle shakes when starting!

My conclusion:
It's not the clutch or oil leaking from a seal, because those are still 'cold,' but rather the engine mounts that are somehow becoming soft due to the high temperatures.
Therefore, the effect described above can be explained as follows: After a long drive on the highway, the engine mounts are also heated up due to the residual heat from the engine.

Now, let's get to the actual questions, since the trial installation of the storage systems doesn't exactly seem to be subject to entertainment tax...
1. Which warehouses might be affected?
2. Can you see it from the warehouses?
3. What is the price of these items?

Best regards, Kassen.

Quote:

I've had this rattling noise for years, but it only occurs when the engine and transmission are REALLY warm (after a minimum of 200 km driven on the highway). Therefore, while it is quite unpleasant, it rarely happens to me.

Do they still shift gears properly when this condition occurs, or do the gears get stuck when shifting?

If it's not separating properly --> the pilot bearing is jammed.

"Something similar happened to me with my AJM (same principle) during a longer vacation trip. After the car had cooled down, everything seemed to be fine. However, on the way home, at the Croatian border, the bearing failed to the point where it was impossible to shift gears with the engine running. At first, I thought it was a clutch problem." So, I carefully carried the car home, a distance of 1200 kilometers.

Under normal circumstances, the damage may not have occurred.

Unfortunately, I had to replace the transmission input shaft because the bearing surface was severely damaged. Nothing remained of the pilot plant except for the metal powder.

Hello BM,

It separates perfectly, whether it's cold or hot.

However, the gears can be a bit more difficult to engage when it's very hot and the engine is warm.
Normally, the transmission shifts smoothly.
It's not exactly new anymore: 230,000 km and almost 14 years.

Best regards, Kassen.

Hello,

I'd like to chime in here. I'm familiar with this problem, as I've been dealing with it since I bought my used Passat 7 years ago. The squeaking typically occurs on warmer days and after prolonged driving.
Sometimes, it feels like the engine is being ripped out of its mountings. In addition to that, there are knocking sounds – this is the most extreme manifestation of the problem. It mainly happens in first gear. The noise is present when starting to move and, to a lesser extent, when reversing.

A few years ago, when I wasn't ready to accept it, I once slipped the clutch in third gear, causing it to smoke. After that, it was better for a few days. In that regard, focusing on storage might not necessarily be the right approach.

Bye.
peace

Quote:

In that regard, the focus on storage might not necessarily be the right approach.

It's also quite possible, but if it turns out to be a genuine vintage piece and is in excellent condition, it could become very expensive.

Perhaps it has already disappeared . There are no more switching difficulties, but that would explain the jerking -- it could be, but it doesn't have to be.

Quote:

Hello BM, It separates perfectly, whether it's cold or hot. However, the gears can be a bit more difficult to engage when it's very hot and the engine is warm. Normally, the transmission shifts smoothly.

That's how it started for me too, after I had really used the phone extensively, from Düsseldorf all the way to behind Rosenheim.
After Austria (where the speed limit is 130 km/h), things improved. At our vacation destination, we drove about 1000 km, and we only noticed a slight jerking. On the way back -- see above.

Sometimes, it feels like the engine is being ripped out of its mountings. In addition to that, there are knocking sounds – this is the most extreme manifestation of the problem. It mainly happens in first gear. The noise is present when starting to move and, to a lesser extent, when reversing.
pax
Yes, I can confirm that!
When I really think about it, it's particularly noticeable when driving uphill with a trailer (and therefore a heavy load).

A few years ago, when I wasn't ready to accept it yet, I once made the clutch smoke in third gear. After that, it was better for a few days.
Have you been warming up the car properly during these days?
I sometimes experience problems for days or even weeks, but it's often related to temperature.

Stupid question (I just haven't looked it up yet): How many engine mounts are there on my A4 (3 for the engine and 2 for the transmission)?

Tomorrow, I will take a look at the FILE .

Best regards, Kassen.

Quote:

Have you warmed up the car properly during these days?

I performed this aggressive action on the clutch at a moment when the jerking was particularly noticeable. Afterwards, it immediately disappeared. In the days that followed, the conditions were such (longer drives, warm weather) that the problem should have reappeared, but it didn't. However, I only performed the test once out of pity for the clutch.

Bye.
peace

Hello fellow enthusiasts,

Here's an update on this topic, which is already a bit old.

I found the reason for the clutch slipping more or less by chance .

I've been having problems with my crankcase ventilation system for what feels like an eternity – the lower left side of the engine has been getting progressively more oily.
And you can only see it from below, when the soundproofing has been removed; from above, everything is obscured by the tangle of pipes.
Sometimes the flange of this plastic part would crack, sometimes it would be deformed, or the seal would be crushed.
In other words, it has almost always leaked .
Before I sealed the flange permanently with sealant, I replaced the original gasket (which was already quite compressed) with a new NBR round gasket with dimensions 28x3.5. It's a bit thicker, but it still fits into the existing groove.
Now that the device is reassembled, and it has been more than 3000 km, everything is still sealed .

And last but not least:
Since then, I haven't had any problems with the jerky clutch, even after long drives (which would normally cause the engine to overheat).
It is likely that small amounts of this oil entered the clutch bell, which then led to this problem .

BTW: I used to really struggle to reach the flange screws of the EGR valve using a long Allen wrench.
Solution: Simply remove the fuel filter from its bracket and gently pull the coolant hoses that are in the way to the side using a ratchet strap.

Best regards, Kassen.

This self-healing process is difficult to imagine. If the clutch is oiled, it is oiled. That oil won't simply disappear immediately after an oil leak is fixed. Furthermore, a leak in the described location won't necessarily result in oil on the clutch disc or pressure plate. It's going downhill.
hg
Herbert.