monkie

Thank you for all of the comments and ideas so far. Richard, don't worry. Your turbo is the one I've fitted a CHRA to, not this turkey that has got all the slop in it. I only use branded diesel from Shell, Esso, BP or Texaco. Mostly off the A303 so it won't have sat there long. Everything else has been fine when inspected. No damage to the head gasket, not damage on the keyway and as I said above the timing is spot on. The injectors had new nozels and were tested in 2017. The pump I have done nothing with. I think for peace of mind I will send them off for testing as that is a good suggestion. I think a good point has been made about the pattern of damage on all 4 pistons. I'm sure there must only be 1 or 2 factories manufacturing these right? But the damage does make me think the pistons just might have not been to spec. They were for the 19J and not 12J as they have the Teflon coating. Please keep the ideas coming... I'm at a bit of a loss.

This had gone through my mind but I can't work it out. The injectors a reconditioned ones. The timing is spot on (I checked with timing pins while the engine is stripped down). What sort of fault with the FIP could cause this? The oil getting in was obviously not enough for a full run away but enough to cause it to start knocking. The day after it started up and ran fine (I took a risk doing that I know).

I case anyone is wondering the order of the pistons from top to bottom in my pictures are 1, 3, 2, 4. The surface rust on the rings is becuase I took the head a few days ago and only had time to get the pistons out today. the bores have been wiped with an oily rag to protect them from rusting. I also found a leak on the exhause manifold as a bolt had fallen out!

I think I have been very lucky in avoiding a runaway engine here. The massive amount of slop in the turbo combined with the dry airfilter makes me think the turbo oil seals failed and it started to run off it's own oil causing the temperature to shoot up on the piston surface. There was a lot of oil in the blue pipe from the turbo to the engine and the pistons look like they have a lot of burnt oil residue stuck to them. It isn't the soft diesely soot. Those pistons came from (ahem) a blue box, but I'm afraid I have missed the 2 year warranty as it was the summer of 2017 when I fitted them. I doubt they would cough up anyway as its likely the turbo failed. I have got some AE branded ones on the way. Lessons learned here - no blue box items on a rebuild and don't trust an old turbo! The good news is bores are fine and look just like they did after I had honed them on the rebuild and amazingly those pistons aren't cracked!

Was driving along a few weeks ago after along run and my engine started to make an intermittent loud knocking noise and smelt hot and of burning oil. I got it home by driving very very gently. First thing I looked at was the intake system. No oil pre turbo. The turbo had loads of play in it. So I took the head off to see what had gone on inside. Had a shock to see all of the pistons showing signs of burning away on the ceown, number 4 was particularly bad. Fortunately the head is in order and I have a spare turbo with a new CHRA fitted. So new pistons for me then

Interesting read. Am I the only one at first glance of the link thought it was advice from Asda?!

I noticed this and it's why I hate measuring things using inches. 20 thou is 0.508mm which added to the standard size is the max shown above of 90.903mm. I thought you could also get 40 thou oversize but that would take you way over.

Email sent

Now you have the right tools, take your time and measure the bores carefully. When you've done all 4, repeat to see how precise you are. If your measurements are within the tolerance for the +20 pistons, then you are working from a known point and not just taking someone's word for it, no matter what their experience maybe (they and you don't know what's gone on internally to the bores since the last rebuild). I made an excel spreadsheet with the workshop tollerences and a space to add my measurements (3 replicates to test my precision). I can send you it if it would be helpful. If so, PM me your email address.

Wow, I thought they were good from what you said before, but if they can measure cylinder wear from a photo... I'm impressed!

I don't agree. I would never advocate putting a second hand engine you have bought from someone straight into your vehicle. Tdi engines are practically antique now; will be over 20 years old, high mileage, unknow service history and unknown life i.e lots of towing or off roading. This is not as good as new by my definition. The engine you have is a known. You have got this far, I would continue the work you have done so when you are finished you have an engine that really will be as good as new and you are confident the work has been done correctly with parts from a trusted source.

Undo the mounts, then take the tunnel off from the bulkhead to gain access to be able to undo the bell housing bolts. It may involve crawling on the floor to undo the lower bolts. An engine crane will be particularly useful.

You've come so far with the work on this, I would be tempted to make a commitment and take the block out and send it off for thorough inspection and then any subsequent machining as necessary. That way when you do put it all back together you will be confident you have a sound engine with no stones unturned. Imagine having got so far if you put it all back together and it still wasn't right, you'd be kicking yourself at having to repeat it all only to have to remove the engine anyway. With the engine out you can also replace the clutch and rear crank seal to tick another job off the list for some time to come. Go on, do it

I think Red90 is saying that white "smoke" is either vaporised fuel (injected too late to burn) or vaporised oil (oil not burnt in the engine but somehow getting into the hot exhaust gasses and vaporising, maybe from the turbo). It is of course very likely to uncover 1, 2 or more problems when you dig into an old engine. With this in mind keep your investigation going as you remove items from this engine. As you did with the valve stem seals and kept on going.

This is quite a useful link here for measuring cylinder bores.

I would strongly advise getting those bores measured properly now you are this deep in. Your engineering shop sound really helpful. It may be easiest to remove the block and get it to them because if it does need boring then you'll have to take it to them anyway. If you want to do it yourself then you need a bore dial gauge to do it properly. You take measurements for ovality, out of round and taper. Then compare your findings to the tolerances in the workshop manual.

I've had valve stem seal problems in the past and it tends to clear quite quickly because it's just accumulated oil from when the engine is off. Red90's explanation sums it up perfectly. I think your problem will turn out to be high crank case pressure pushing oil through the breather system.

I would consider seeing a haze behind you in headlights at night is normal for a Tdi. It's hard to say where the oil has come from at this stage, how oily is the breather pipe where it enters the induction system? With the pistons out look for scuffing on the skirts, stuck rings, sooty scorch marks as evidence of gasses getting past the rings, scoring and/or glazing on the bores. Were the injectors oily on the body that's is located within the head when you pulled them out?

To be honest it has one of the key features I look for when buying a vehicle

It can also carry through from the breathing system if crankcase pressure is high.

Is it black smoke when driving? Provided all else is fine (ie the valve clearances) personally I wouldn't worry. I have mine set so there is no smoke at idle but a blackish haze when my foot is down.

Not something I have ever bothered with but a quick search on Frost's website came up with this and I have been more than happy with the products I have used from them in the past. Someone with some experience of said products will more than certainly come along.....

Absolutely fantastic. That had me chuckling. Particularly liked his evidence for being in the costs del sol

This happened to me too at the end of last year. I think water got in by following the loom down to the relays.

That's a good idea. If they come back to me I will start asking all sorts of questions to make them go on a paper trail. It's not a car park I use much as its near my mum's rather than near me. It was a pay and display but not linked to a shop otherwise I would have asked the shop to contact them to cancel the fine. The only way theybhave my number plate details is because of the Apr as you enter and as you leave. The only pictures they have is of me entering and then leaving. No evidence provided to support their allegation. I paid with loose change not bank card, but then I wouldn't send them a copy of my bank details anyway. Its not on me to disprove them, they have to prove I was in the wrong which I refuse to accept. I have had this happen before in a council run carpark and the "evidence" they provided wasn't even my car on the closeup picture allowing me to have a field day on their presentation of evidence! They can keep writing to me if they want to. It will be fun as they don't know my name or the make and model of my vehicle. I think they are going to find it tricky without those details