Timing Belt Pulley Fixed: Repair & Solution

Okay,

"My timing belt pulley is stuck again. No wonder it didn't last. The surface of the crankshaft wasn't particularly flat. Also, it seemed that the main contact area was more towards the inside than on the edge. I carefully removed the chamfer on the thread with a grinder and then used it to grind out the cone from the old timing belt pulley with valve lapping compound, turning and grinding. It wasn't perfectly flat now, but there was almost no play left. Well, I tightened it to 90 Nm plus about an additional 1/3 of a turn instead of 1/4. Hopefully, this will hold. I'm not entirely sure if the pressure decreased slightly during the last tightening. Could it be that I overtightened the screw? In theory, this high-strength material should break off immediately, right? And what actually happens if this thing breaks at 180 km/h on the highway? Does anyone have experience with whether it would instantly stall the engine and lock the wheels? If so, that would be life-threatening."

Best regards,
Fuschia.

Hi,

Fuschi68 wrote:

And what actually happens if the thing fails at 180 km/h on the highway? Does anyone have experience with whether it immediately cuts off the engine and locks the wheels?

Well, I would say that the camshaft breaks first, then all the valves get stuck and bent, which means nothing is in the way of the pistons anymore, and the engine debris rolls freely out.

Having experienced something similar happening to my brother's Audi 100D (with a 5-cylinder engine) while driving at a slow speed, I can say with certainty that...

Quote:

Then that would be life-threatening.

It makes a terrible noise, but it's not worse than a good braking maneuver.

Sure, here is the translation of the text from German to English:

"Hi,"

It also depends on whether the clutch can actually handle it in the highest gear, or whether it will simply slip.

"Many years ago, I seized the engine in my Trabant (the cause was a damaged connecting rod bearing). This slightly tilted and pushed the piston upwards towards top dead center until the engine stopped. The car continued to roll thanks to the freewheel mechanism. I didn't immediately realize what had happened (these things sometimes stalled), and I tried to start it in third gear (without putting it in neutral). This provided quite a bit of braking, but the wheels were still spinning... only the clutch slipped. Incidentally, the engine was so seized that we couldn't turn it even with a hammer. Fortunately, it was very easy in 1992 to get a complete engine from the scrapyard."

I suspect that the situation would be similar with a TDI engine, although this is unlikely if the scenario described by Bertil doesn't occur.

Best regards,

January.

Fuschi68 wrote:

Well, I've now tightened it to 90 Nm plus approximately 1/3 of a turn instead of 1/4. Hopefully, this will hold now. I'm not entirely sure if the pressure decreased slightly during the last tightening. Could it be that I overtightened the screw?

Hi Fuschi,

You probably didn't overtighten the screw... how did you hold it in place? Fifth gear or a special tool? I would suggest trying to get that quarter turn. I remember a case here on the forum where the screw wasn't tightened enough, and that's why (the crankshaft or the screw ) broke off. Let's see if this works... then maybe the next potential candidates can skip the trip to the dealer (I never want to go there ).

haehnlein wrote:

You probably didn't overtighten the screw...how did you hold it in place? Fifth gear or a special tool? I would try to get that quarter turn fully tightened. I remember a case here on the forum where the screw wasn't tight enough, and that's why (the :?or the screw) broke off. Let's see if this holds...

Fifth gear, someone was pressing the brake, my brother and I were pulling on the lever with all our strength. The clutch also slipped a bit.
The 1/4 rotation is complete. After all, 1/3 is 60 degrees, not just 45 degrees .

Just to let you know: I previously cleaned the screw, the threads, and the contact surfaces thoroughly with brake cleaner to ensure a good fit between the metal parts and that the wheel is securely fastened in the position where it had the best fit. The screw is secured with a drop of high-strength Loctite (and probably won't come loose again ).
Now I just hope I've managed to align the crankshaft stub properly, so that it will hold up. Unfortunately, the timing belt pulley isn't perfectly centered. The vibration damper is moving back and forth by about 1-2 mm. However, this was already the case after the very first incident of this type, and it lasted for a whole 90,000 km back then.

Okay, since no one knows how long this will last, I would just say: If it doesn't work, then I will post about it here. But if it does work (hopefully ), then I won't post anything. So, as long as you don't hear anything about it, my good old 1Z is still running.
By the way, that has been the only problem the engine has ever had. It has 270,000 kilometers on it, and everything except the timing chain wheel and serpentine belt is still original, and it still barely uses any oil (about 0.09 liters per 1000 km).

Best regards,
And thank you for your advice and tips. Without them, I probably would still be trying to weld the wheel.

Fuschia.

Jan6K wrote:

I suspect that the situation would be similar with a TDI engine, although this is unlikely if the scenario described by Bertil doesn't occur.

Hi Jan,

There, the block gets stuck. Then your scenario applies. But in the case of a timing belt failure, the head seizes. In this process, the camshaft, which controls the valves that are pushed by the piston, is simply destroyed. In other engine designs, the rocker arms break (or bend), but the effect is the same.
I've seen various (racing) engines with broken timing belts (or chains!), and in every case, the crankshaft was completely destroyed.
Even in an engine where a connecting rod had broken off (leaving a hole in the engine block), the detached piston traveled towards the valve area and shattered the camshaft. The timing belt even survived this event! You couldn't see the damage to the cylinder head from the outside, but that five-piece camshaft was really something }.

Fuschi68 wrote:

Fifth gear, someone was pressing the brake, my brother and I were pulling on the lever with all our strength. The clutch also slipped a bit. The 1/4 rotation is complete. After all, 1/3 is 60 degrees, not just 45 degrees

.

Shouldn't a quarter turn be more accurately described as 90° (360°/4 = 90°), and a third of a rotation as 120°?

Best regards,
Crunch.

Mampf wrote:

Shouldn't a quarter turn be more accurately 90° (360°/4 = 90°), and a third of a rotation not be 120°?

Oops, that's embarrassing . Of course you are right.

Best regards,
Fuschia.

Fuschi68 wrote:

Oops, that's embarrassing . Of course you are right.

Well, at least we both embarrassed ourselves . (I thought it was 1/3 of the quarter turn) -> It was late (or early) for both of us .

Fuschi68 wrote:

By the way, this has been the only problem the engine has ever had. It has 270,000 km and, apart from the timing belt wheel and serpentine belt, everything is still original and it still barely needs any oil (about 0.09 liters/1000 km).

My father also has an Audi 80 1Z with almost 280,000 km. Everything is original except for the injectors and three ribbed belts and tensioners ( ). I've long believed that the quality seems to be better at Audi (my friend has an A4 1Z with 240,000 km -> everything is original except for the NHG) ...

@hähnlein

hello christian

'And my 1Z engine is definitely not one from the Audi parts catalog, and it has 225,000 km on it. Besides the injectors, everything else is original! (Except for the timing belt, serpentine belt, and related tensioners, of course!)'

I don't think it's possible to say so generally that Audi has better quality! In my opinion, it always depends on the driving and handling style! Only full throttle and no care will eventually come back to haunt you!

joergs wrote:

I don't think it's possible to say so generally that Audi has better quality! In my opinion, it always depends on the driving and maintenance habits! Only full throttle and no care will eventually come back to haunt you!

Hi Jörg,

Sure, you're right, but I don't just mean that in relation to the engine. Well, that's also why an Audi is more expensive. I probably only mentioned it because I bought my Passat "sight unseen" and am a bit frustrated about it. With that car, everything that could possibly be wrong *is* wrong, and that's at 180,000 km... even the fuel gauge shows 10 liters too much... well, you know my story .

haehnlein wrote:

Except for the nozzles...... everything else is original.

I still have the original nozzles in my car, and I've driven it for years, mostly on the highway. I have to say, this stuff is durable. The only thing I was meticulous about was the oil changes. I even changed the oil every 10,000 km. (At my dad's place, they use cheap oil because agriculture needs a lot of ), and it seems like that has paid off.

Best regards,
Fuschia.

@haehnlein

hi christian,

It's probably as you say. One mainly sees their suffering and compares it to what one already knows. And logically, in your case, that's what comes out!
but one thing is a fact: before my 1Z, I had an Audi 80 type 89 with a 1.8L engine and 75 horsepower. Just in terms of seat comfort, there were worlds between the two cars. Not to mention the bodywork and driving feel. Of course, Audi comes with its price! But my new Passat 3BG is amazing considering all of that. There are galaxies between my 1Z and that car. So, enough off-topic talk!