EA288 2.0 TDI Compression pressures

[Crasher]

If it was a customers car we would only fit an exchange engine. If it was my own (and hell will freeze over before I buy a Diesel) then I would hone the bores with medium grit stones, a couple of passes up and down to get a nice 45 degree cross hatch and then rebuild with new Mahle pistons and an AMC head, the original valves and cams but new lifters, con rod bearings gaskets etc. That it has bore wear strongly suggests to me that metallic debris has been getting in from the EGR valve so I would not even consider not replacing it. I would also have the turbo rebuilt by Midland Turbo and the DPF cleaned by DPF Clean Team, two excellent companies. I rebuilt the TDI engine in a friends Octavia as a favour, 250k miles and absolutely zero bore wear although they were so mirror polished you could do your makeup in them.

[Ben_T]

Thanks so much for your advice! I've now honed the cylinders, have checked the ring to groove clearance on the pistons (I think it was 0.06 mm) and they've cleaned up nicely so I'm going to take a punt and reuse them. New rings of course (once the spreader tool I've ordered arrives). The grooves were full of sooty deposits (now removed) so that probably wasn't helping anything. New conrod bearings too, plus all of the obligatory gaskets. DPF cleaned now too.

The EGR cooler seems fine, there wasn't any scoring on the cylinder walls and the intake's free from metallic debris, so is it still wisest to replace this as a precaution?

Overall, as I'm doing the work on my driveway (where replacement engine fitting isn't a good option) I've decided to do the above and keep costs down. If I can get a few more thousand (hopefully trouble-free) miles from it then I'll be pleased enough. But, with so many parts worn (turbo, clutch and DMF included!) then I think the most sensible option's a replacement engine longer term. Assuming it doesn't come with the same problems!

Was your friend's Octavia an EA288? Hard to imagine one lasting that long... And damn, that's why my lipstick was such a mess. Should have left the engine a tad longer

[Ben_T]

Quick update, for anyone else with this issue.

The engine's now back together, complete with new cylinder head! New (Goetze) piston rings, head bolts, gasket, injector seals, intake/exhaust manifold gaskets. Cylinders honed, as above. I primed the fuel system with VCDS before trying to start it and it more or less started as though nothing had happened. Happy days. I then followed Mahle's running in procedure by running at fast idle for 15 to 20 minutes to warm it up, followed by a gentle 30 minute drive, constantly varying engine speed and load. Then 6 bouts of firmly accelerating from 1500 RPM up to just over 3000, before engine braking back down to 1500.

Now, 200 miles later and it runs very nicely. Seems to be giving 2-3 mpg more than before, too.

But...

It still cranks for longer than I feel it ought to before it starts when slightly warm. And the exhaust fumes still stink of oil. Before the rebuild it had 320 PSI compression pressure, it now has just 280 (I only tested one cylinder mind you). I'm going to see how things go between now and the 1,000 mile mark, but it's not looking good. Perhaps the block was just a little too out-of-round for the new rings to seat. Or I'm being impatient. Or, I did something else wrong! But, at least it drives, and well. Perhaps it'll get a new engine after all...

[Crasher]

This sort of disappointment is why we won't rebuild them, just fit genuine exchnage and then it is the dealers problem.

[Ben_T]

Another update...

The oil level dropped fairly sharply up until around the 400 mile mark post-rebuild, then seemed to stop. I replaced the oil and filter at 1,000 miles (with 0W-30 oil) and am now nearing 3,500 miles in total since the rebuild and the oil level's about to hit the bottom of the dipstick crosshatching, so the oil consumption has improved! But it's still bad...

Previously on 5W-30 oil it would have used 1 litre per 500 miles or so, so an 80 % reduction in consumption perhaps. I'm also wondering if the 0W-30's making things worse.

There's a slight oil leak between the turbo and oil return line so this will be contributing somewhat.

So, I'll see how it goes over the next few thousand miles. Weirdly, despite the much reduced oil consumption and still having the DPF present and correct, it's started kicking out blue smoke on firm acceleration. I think perhaps the DPF's lost some of it's platinum having been washed out twice, so that won't be helping. Not sure what else might be going on!

Other than that, it's driving as well as ever. Semi-success perhaps, but I'm never satisfied