1.9 TDi Octavia Engine Blow

[Gary B]

I have an 03 plate 1.9 TDi Octavia that I use as a taxi. The car has done 130,000 miles and is regularly serviced.

I have had the engine blow on me at 100,000 miles. The symptoms right before failure was for the engine to rev to full revs before the engine went bang..... Investigations showed that the the turbo checked out ok. No answers were found as to the cause of the failure.
A reconditioned engine was fitted and everything was ok.

Recently, the engine was running a little "lumpy" at idle. Using a diagnostic machine, the manifold air regulator valve was found to be faulty. A new valve was fitted and the car was taken for a test run. After only a few minutes, the engined went to full revs before blowing up......
A bit of a mess. Again, the turbo was favourite, but on strip-down the bearings and turbine blades were fine. A little oil residue was found in the pipework, but nothing that looked out of the ordinary.
Investigations are still on-going as to the cause of this second failure. I don't want to go through the expense of fitting another engine until I am sure that the root cause has been found.

Could this be a fuelling problem were the engine management system thinks that engine needs more fuel? Could the replacement manifold valve be a coincidence seeing as the failure also happened with the original valve fitted? Why didn't the rev limiter stop the engine over revving?

All these questions. I would appreciate it if any one could help with the diagnosis of this problem. Has anyone had this happen to them and if so what was the reason for the failure?

Thanks for your help.

Gary B

[TKW]

Ouch! That sounds interesting / worrying as I only hear good things about the long lives of the diesel engines. I hope someone here is able to suggest a cause for these failures.

Please keep us updated.

[fordfan]

I have heard of diesel engines doing this, the cause has been attributed to the engine using its' own oil as fuel and the way it gets into the intake system is through the turbo (poor/worn oils seals?).

[Td-eye]

Originally Posted by fordfan

I have heard of diesel engines doing this, the cause has been attributed to the engine using its' own oil as fuel and the way it gets into the intake system is through the turbo (poor/worn oils seals?).

That sounds both scary and quite plausible.

Of course, in that situation you would have little control over the engine which would presumably just rev to destruction as it sucked in more & more fuel (engine oil) ... a scary & expensive situation indeed !

I suppose stalling the engine would possibly be one way out of that situation if of course you were quick enough to realise what was happening at the time.

Very interesting !

[cheezemonkhai]

Well if it is that and they checked out the turbo before they replaced the engine last time, I'd say you have some recourse on the previous repairer.

[Kandy]

On scrap heap challenge, the 'Proper job' farmers messed around with a regulator or something on a big diesel, they cut the fuel but it still revved to destruction. They suggested it was feeding off the sump oil somehow???

Just for future reference, how do you stall/stop a runaway diesel engined car? Surely it would just destroy the clutch?

[Td-eye]

Originally Posted by Kandy

Just for future reference, how do you stall/stop a runaway diesel engined car? Surely it would just destroy the clutch?

Yup, quite possibly it would !

I don't know if you could actually manage to stall it but I'd think it's worth a try and I'd try a high gear, foot on the brakes & let the clutch up quickly but gently.

A fried clutch is preferable to a blown engine so it's got to be worth a try ?

The other way I suppose (if you had time) would be to somehow block the air intake, although that might be a bit more difficult ?

[mbames]

I have stalled mine by flipping the EGR flappy thing....

High gear, and just bring the car to a stop (if travelling down the road)

[Lummox]

Does sound like its running on its own oil.

If its not the turbo and your not overfilling the engine oil im not sure what could cause this twice on two different engines.

[barney_b]

I thought that the farmers tried covering the air intake and it still went pop?

Very odd that this has happened on two seperate engines, would suggest to me that what caused it wasn't changed the last time they replaced the engine. Not very helpful I know.

[Lummox]

If you block the air then it will stop, an engine cant run without air, pure physics.

[51octytdi]

Originally Posted by Lummox

If you block the air then it will stop, an engine cant run without air, pure physics.

True, but you'll probably struggle to block the intake sufficiently. Besides, it involves leaning over the engine with the bonnet up. Personally, I'd rather be running very very fast in the other direction. When it goes bang it could easily fire out pointy bits of hot metal.

I've got a video clip from that episode of Scrappy Races. The Barley Pickers removed the fuel line, held a cloth over the air intake and then let off a CO2 extinguisher off into it as well. It's hard to tell if that stopped it or if just broke.

Nearly died laughing watching it the first time

As for the Octy blowing up by itself, twice, well that just seems weird. That tractor engine blew up because when Andy was adjusting the governor, the nut came off in his hand

J

[Lummox]

I can say from personal experiance that on an Octavia 2 diesel the EGR/throttle flap does close it off enough to stop it...lol

[ivan-b]

I took my 42000 mile 03 plate Tdi 90 Octavia to a local VAG specialist for a brake fluid change. When I returned, the garage had had the engine blow on them whilst road testing. As of yet no explanation has been found. When I contacted a local engine supplier, they asked if it was for a Skoda, and said that they knew of three others which had revved to destruction. This had also happened at the local main dealer during an MOT test. These events all seem to be linked in some way.

Ivan-b

[Tom_vRS]

How random.

This phenomenon of running on its oil until it goes bang is known as dieselling. Other than the turbo seals going though and pumping oil into the inlet, I can't think of any other way this could happen...

Have you ever actually had a replacement turbo?