Glühkerzen schuld? Motor startet nicht | Posts 16+

Henrik wrote:

Now, my question, which has been occupying my mind for the past 5 hours: Where is the glow plug control unit? Don't say that's the engine control unit next to the pollen filter... that costs 900€

.
However, that's precisely the case: the functions of the glow plug control unit are integrated into the engine control unit (ECU) in TDIs.

But in extremely rare cases, this is the cause of the problem, so you should look for the issue elsewhere.

Okay, I suppose I'll have to check (or have checked) the compression first.

Where can I have this done? At a VW dealership? And what is the cost?

Oh yeah, lately it's been really hard to start.

'When started, it idles at 500 rpm and then slowly increases to 850 rpm... which seems plausible given the compression.'

First of all: All the timing belt alignment marks match perfectly.


What does that mean exactly?

If the pulleys are aligned with the markings, it doesn't necessarily mean that the shafts they are attached to are also correctly positioned. That's the problem with the crankshaft sprocket or camshaft after a timing belt replacement...

Therefore, examining the start of injection and the duty cycle could potentially provide valuable insights.

btw: The EDC (Electronic Discharge Coil) doesn't glow at temperatures above +5°C because it's usually not necessary for it to do so.


CU Gremlin.

Okay, something new again.

I'm going to replace the piston rings (and the head gasket at the same time, of course).
Why?
If I seal the ventilation hose between the camshaft ventilation and the air filter, exhaust gases come out of the oil level indicator hole... and quite a lot of them.


I'm still planning to get a compression test done somehow. I went to an independent workshop, but they only had screw-in injectors; mine are push-in. Okay, so I went to VW. It was half past 12 on Saturday. The mechanic tried to tell me he needed 1 hour to remove the glow plugs. I told him I can remove them in exactly 4 minutes and install them in 10 minutes... Anyway, the bottom line is, he didn't want to do a compression test because he wouldn't be able to finish it by 12 o'clock.

But I don't think I'll need it; it's obvious that it's the rings, right?

What parts do I need?
Cylinder head gasket.
Stud bolt.
Camshaft cover gasket.
Stud bolt.
Nozzle guard.
Timing belt.
New screws for the wheels on the timing belt and for the seals.
Diesel filter (which I'm going to replace now).
anything else?

Henrik wrote:

I will replace the piston rings (and the head gasket at the same time, of course). Why? If I seal the ventilation hose between the camshaft ventilation and the air filter, exhaust gases come out of the oil level indicator hole... and quite a lot of them.

I think this diagnosis is a bit premature.

Even healthy TDIs can blow out quite a bit of oil from the oil filler opening, which has a cross-sectional area many times larger than the dipstick tube. This means that if the breather hose is blocked, the oil should be forced out through that larger opening without anything necessarily being broken.

That's just my theory...

I will replace the piston rings (and the head gasket at the same time, of course).
Why?
If I seal the ventilation hose between the camshaft ventilation and the air filter, exhaust gases come out of the oil level indicator hole... and not a little bit.
I think this diagnosis is a bit premature.

Even healthy TDIs can blow out quite a bit of oil from the oil filler opening, which has a cross-sectional area many times larger than the dipstick tube. This means that if the breather hose is blocked, the oil should be forced out through that larger opening without anything necessarily being broken.

But that's just my theory.

That was just a suggestion from 'my' mechanic.
'Quite a bit' comes out, and from the driver's seat, you can see what looks like 'smoke' rising.

Henrik wrote:

Quite a bit comes out. From the driver's seat, you can see what appears to be "smoke" rising.

Probably more smoke than actually comes out of the exhaust pipe, right?

"In my opinion, this is more likely to be emulsified oil (due to the abnormal operating condition = KGE through the dipstick tube) than exhaust fumes."

Could it be that your mechanic only saw an opportunity for a job?
What is the oil consumption like?

No, the mechanic lets me do everything myself; he just provides the workshop and assistance.

Not much smoke rises from it. It dissipates after 20 centimeters.

Oil consumption: less than one liter in the last 2000 km .
It's leaking from either the cylinder head gasket or the exhaust manifold, and a little bit from the oil pan.

Henrik wrote:

Oil consumption: just under a liter in the last 2000 km . It's leaking from either the cylinder head gasket or the exhaust manifold, and a little bit from the oil pan.

Ah, those are (unfortunately) facts that warrant further investigation.

However, besides the piston rings, oil consumption can also be caused by several other factors, especially the crankshaft end seals.

'Definitely, I would have the compression test done beforehand. If the cylinder bores are excessively worn in the top dead center (TDC) area, replacing the piston rings won't help much. In that case, you'll need to bore out the cylinders, hone them, and install new oversized pistons. However, whether it's worth it is your decision. A replacement engine block might be cheaper if the rest of the engine is okay and can be reused.'
However, a compression test should be performed before changing the rings.

Okay, now it's running smoothly again!

I had a compression test done.
Values ranging from 22.8 (cylinder 1) to 24.2 (cylinder 4) bar, increasing uniformly. This is therefore acceptable (target values are between 25-30 bar, wear limit is 19 bar).

I took it to a VW service center to have the fuel injection timing/amount checked during cold starts.
They immediately found the problem: the crankshaft pulley had 0.5mm of play. Apparently, this is a common issue, especially in cars frequently driven on highways, when you quickly release the accelerator at high RPM (which definitely applies to me, as I had just finished a 4-week vocational training program and had to drive 100km on the highway every day).
VW has now glued on a new wheel, but without any warranty. However, it works! But almost 300 Nm of torque is a good way to make the glue come undone...
Alternatively, I would have to replace the entire wave, and I'm not keen on doing that.

Aber es ist schon ein gutes Gefühl: man steigt ein, glüht vor, und der Motor springt an! Jipiee!


I'm going to get a Rover Mini as my second car; it has a 1000cc carburetor engine.

Thank you for your help so far!

Search for "crankshaft bolt". You'll find information about a common problem.

Hi Henrik,

Check the very first response you received in this thread... the solution was already included there.

The problem is very common with the 1Z, which is why several people here in the forum mentioned it right away.

Best regards,

Jan.

Hello Henrik,

Okay, I have no idea what kind of car dealership you're talking about, but stickers, no matter what form they take, are not the solution.
It only needs the crankshaft to be remachined, not the entire crankshaft to be replaced.
Any reasonably competent repair shop can install that for you, including a new crankshaft sprocket and screw, for around 150-200 euros.
I have a lot of experience with this myself, and it's become such a common problem that the solution is no longer a challenge.
HE HE probably used with LOCTITE. Glued !!

Best regards, David.

Okay, you're probably right.
But I don't have enough knowledge to immediately know what to do with a modified crown wheel gear. Everyone starts small.

@David:
Then, please recommend a reputable car dealership or workshop near Berlin.


PS: A stuck KW strut/shock absorber isn't easy to loosen quickly, is it? Do I have to wait until it comes loose again and then grind it?