Hello, 

 

Just a few weeks ago, I bought a used car Skoda Octavia 1.6 tdi 85kw 2018.

 

A few days ago there was a problem, a pair of valve rockers on the third cylinder broke.  The dealer gave me a warranty of one year or 10,000 km, so he bears the cost of the repair.

 

I've heard that in case of an engine head failure, the cams on the camshaft can move, they can rotate.  Can the craftsmen restore it to normal condition or does the complete housing with two camshafts have to be replaced?

6 hours ago, remark78 said:

I've heard that in case of an engine head failure, the cams on the camshaft can move, they can rotate

 

Sounds like a fairy tale, you heard that where? Camshafts have to rotate to function, are you claiming that the cam lobes rotate on the camshaft?

 

I would be more concerned with what had caused both rockers to break.

Of course the camshafts rotate, you didn't understand me (translator). In the case of the 1.6 tdi engine, the cams are pulled onto the shaft, it is not cast from one piece. It can happen that the cam ends a little or rotates around the shaft.

I understand now and was unaware of that.

 

Do you know what caused the rockers to break? Has the head been lifted? Was the engine perhaps hydrolocked? ie driven through a flood?

17 minutes ago, remark78 said:

In the case of the 1.6 tdi engine, the cams are pulled onto the shaft, it is not cast from one piece. It can happen that the cam ends a little or rotates around the shaft.

I find that difficult to believe.

 

I imagine the usual reason for rocker failure is piston valve contact. Often due to cambelt slippage or breakage.

 

There is a procedure and special tools needed to set the camshaft timing. You'll need to follow the workshop manual procedure.

Edited 2 March, 20242 yr by xman

I don't know what caused the rockers to break. I doubt that the engine had a problem before and that the seller repaired it badly. I can't check anything because the vehicle is being serviced by the dealer's mechanic.

Did it happen when you were driving? Was it preceded by anything, noise, lack of power etc?

 

It could have been a cam belt failure but that would normally affect all 4 cylinders.

 

The cylinder ingesting a metallic foreign body could do it, something detached from the intake tract.

 

Or it could just be garage BS, have you seen the broken rockers with your own eyes?

ChatGPT 3.

I bought the car used, at a car dealership. Everything seemed fine, the car is very well-preserved and there were no signs of any problems with the engine head. The only thing I noticed is that it doesn't perform well at low revs, for example, if driving at 50 km/h in fourth gear, it feels like the engine has significant vibrations and makes a strange noise. Otherwise, it ran smoothly and pulled well. Three weeks have passed since the purchase and suddenly it broke down, during light city driving, the engine started running on 3 cylinders, shaking violently and barely moving. My mechanic determined that there is no compression on the third cylinder. So, I returned the car to the seller because I received a warranty on the engine from them. At their mechanic's, I saw broken valve lifters. Now they need to solve the problem and fix the breakdown. I hope they'll do it properly.

Since a major service was done just before I bought the car, I'm almost certain that the engine timing wasn't set properly, meaning that the engine and the engine head weren't synchronized. That's probably why the car behaved strangely at low revs. Since I hadn't driven a car with this 1.6 TDI engine before, I thought it was normal for it and simply required, for example, shifting back to third gear when driving at 50 km/h. That's why the valve lifters broke. The mechanic probably won't admit to it, but I hope the engine head will be serviced properly this time and that the engine timing will be set correctly.

Since a major service was done just before I bought the car, I'm almost certain that the engine timing wasn't set properly, meaning that the engine and the engine head weren't synchronized. That's probably why the car behaved strangely at low revs. Since I hadn't driven a car with this 1.6 TDI engine before, I thought it was normal for it and simply required, for example, shifting back to third gear when driving at 50 km/h. That's why the valve rockers broke. The mechanic probably won't admit to it, but I hope the engine head will be serviced properly this time and that the engine timing will be set correctly.

Or, a more realistic scenario could be the following:

 

The car had damage to the cylinder head, such as a belt breakage, etc. The car dealership imported it and repaired the cylinder head, along with performing a major service.

 

BUT, they didn't pay attention to the camshafts' lobes, which can slip/rotate around their axis.

 

What happened next is what happened...

Assuming that the cam lobes are in fact separate from the camshaft, (and shrunk onto it) I think if would take an extraordinary amount of lateral force to force them to rotate on the shaft, more likely to break the camshaft.

Does anyone know  if the cams are actually manufactured this way - or is the dealer referring to the variable cam timing mechanism?   

10 minutes ago, Warrior193 said:

is the dealer referring to the variable cam timing mechanism? 

Good call, and vastly more likely I reckon.

Although I very much doubt the concept of individual lobes pulled onto a shaft, trawling Youtube vw 2.0tdi camshaft videos I see these close ups and wonder ???

 

 

I've also picked up on an American forum

The RO states "removed timing cover & ensured crank, cam, and injection pump were timed correctly. suspect damaged camshaft, removed valve cover, found broken rocker arms & cam lobes out of phase. camshafts faulty and require replacement"

 

 

https://forums.tdiclub.com/index.php?threads/ea288-cam-issue-15-gsw.506452/

Edited 3 March, 20242 yr by xman

That's exactly what I was telling you about.

I've read of quite a few 1.6tdi cambelt breaking, far more than normal and often shortly after having a cambelt change. I even witnessed one broken on a 2016 Superb less than 100m from our house. Company car owner claimed that the cambelt had been changed only 5000 or 6000 miles earlier.  IIRC that car had just over 100,000 on the clock.

 

So I am now thinking that "camlobe slippage" may be an issue on this particular engine and causing the cambelts to break.

 

Must be a cost saving exercise if true.

 

 

Edited 3 March, 20242 yr by xman

https://www.jandeengineering.co.uk/camshaftalignment.html

You learn something new every day 🙂

Wow, who'd've thought they would find another way to make the CR1.6 engine  go wrong? 

Edited 3 March, 20242 yr by Breezy_Pete

8 hours ago, remark78 said:

Since a major service was done just before I bought the car, I'm almost certain that the engine timing wasn't set properly, meaning that the engine and the engine head weren't synchronized.

 

You can rule that out, engine timing has not been adjustable or a service item for over 3 decades.

 

Cam timing is frequently done incorrectly when a cam belt is changed.

 

Now we have seen that you are correct that the lobes are a shrink fit, and thankyou to you and the others who have educated me and others, I think your scenario of a previous cambelt failure and cam movement is plausible but equally plausible is that this could have been the first instance of cam belt failure, maybe you saw the belt intact.

 

In any case your concern that camshafts with misaligned lobes might be re-used is valid, I dont know the consumer laws in your country and you would have to prove a hypothesis, I could easily check the valve opening angles with a dial guage and crankshaft protractor, I was doing it all my previous life building race engines. Sadly you have very little hope of finding a modern garage with the interest or competence to do the same, your only possibility is to learn how to do it yourself and do so when the vehicle is returned, its not difficult but time consuming, what you will be looking for is different opening and closing angles between the slipped and unaffacted cam lobes.

 

21 minutes ago, Breezy_Pete said:

Wow, who'd've thought they would find another way to make the CR1.6 engine  go wrong? 

 

Aint that the truth!

 

Almost every day I learn another reason not to own a newer car, consumerism must be a very powerfull and addictive drug for people to expose themselves to the grief awaiting them buying a new or newer vehicle.

I think they must also use the same technique on the 2.0tdi perhaps only on certain variants or model years. The screenshot I posted earlier was from a 2.0tdi EA288 engine.

3 hours ago, Breezy_Pete said:

Wow, who'd've thought they would find another way to make the CR1.6 engine  go wrong? 

Joking aside, I just cannot fault mine. Cambelt & pump are the only things its had done

The engine head is currently at the machining service, they told me they will handle it with maximum quality.

 

They also advised me to consult with the mechanic to replace ALL valve lifters and rocker arms, not just the damaged ones, even if I have to pay extra for it. I called the mechanic, he assured me that he will indeed replace all valve lifters and rocker arms, as well as camshafts, he won't risk anything.

In Friday I picked up the car.

 

They say the repair cost 1,100 euros, everything was done, the engine head was machined, all rocker arms and hydraulic lifters were replaced, as well as camshafts.

 

The repair was covered by the car dealership where I bought the car, they turned out to be fair and honest!

 

These days, weeks, I checked the car wherever I could, CarVertical, I also found a Belarusian website KA.BY for 1.2 euros, which gives you the mileage of the car based on the VIN number and then you can request an extended report. Everything indicates that the mileage is genuine, 161,000 km. Also, the vehicle is very well maintained.

 

I have no idea what happened, when I bought the vehicle, a major service was done even though it has higher mileage, they say it was done just as a precaution because it doesn't cost them much, and they provide a warranty on the engine, so they want to be more confident. Maybe the mechanic messed up something then, or maybe the service was done because of some accident that wasn't adequately repaired, I don't know, that will remain a mystery.

 

In addition, the injectors have been checked, they're excellent.

 

Nearly 2 weeks of great nervousness, stress, negotiations, they're behind me now, may it not happen again. Moving on, I hope the quality of Skoda will now show...

 

Thanks to everyone who participated in the discussion and commented, every comment was useful in its own way!