300 Tdi Rebuild

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Plus once the head's off you can at least check the honing by eye if nothing more as a plus!
Absolutely, mate. If it doesn't look good enough I'll make the decision about doing it while the head is still off. Can't see it being easy to get the honing tool rotation speed and up and down movement synchronised to get the correct honing mark angle. Potential nightmare :eek::rolleyes:
 
Can't say I've done it personally (in situ block work of that level) but I have a mate who briefly resurrected an especially wretched old astra that was guzzling oil like water. (which it incidentally also guzzled, hence the strip down).

I believe since the original factory honing marks were still good, it was a 240grit flexi hone job, with no cutting fluid used - so it only removed a very very small amount of material and the hone can only follow the existing marks rather than re-cut them. Really only removes glaze and freshens up an existing job to take news rings (or maybe promote a better mating of newish rings for your situation?), as far as I remember it worked okay - though within the year it ended up being written off by a bin lorry, so might have been a bandage fix rather than long term. I'll drop him a line and ask

Anything more than that, ie re-cutting them entirely and the block will have to come out, some levels of bodging really are too much after all :D

Fingers crossed that by the time warm weather arrives it has settled down off its own back mind!
 
Can't say I've done it personally (in situ block work of that level) but I have a mate who briefly resurrected an especially wretched old astra that was guzzling oil like water. (which it incidentally also guzzled, hence the strip down).

I believe since the original factory honing marks were still good, it was a 240grit flexi hone job, with no cutting fluid used - so it only removed a very very small amount of material and the hone can only follow the existing marks rather than re-cut them. Really only removes glaze and freshens up an existing job to take news rings (or maybe promote a better mating of newish rings for your situation?), as far as I remember it worked okay - though within the year it ended up being written off by a bin lorry, so might have been a bandage fix rather than long term. I'll drop him a line and ask

Anything more than that, ie re-cutting them entirely and the block will have to come out, some levels of bodging really are too much after all :D

Fingers crossed that by the time warm weather arrives it has settled down off its own back mind!
its impossible to cut original honing marks,you take them off as your cutting fresh anything else will polish of before rings bed in, its quite common to hone a block in situ or was, i still do 1 or 2 a year
 
its impossible to cut original honing marks,you take them off as your cutting fresh anything else will polish of before rings bed in, its quite common to hone a block in situ or was, i still do 1 or 2 a year
How do you get the right angle, James? ie the up and down speed relevant to the speed of the drill?
Do you think I'm barking up the wrong tree with the valve guides? The new valve stems were too slack I reckon, but I didn't check them for sure with the test dial. Big regret, but thought new seals would be enough.
 
its impossible to cut original honing marks,you take them off as your cutting fresh anything else will polish of before rings bed in, its quite common to hone a block in situ or was, i still do 1 or 2 a year

How do you get the right angle, James?

That's some interesting info, i'd no clue you could get it done in situ properly.

Bodes well for fixing a potential worst outcome at least.
 
How do you get the right angle, James? ie the up and down speed relevant to the speed of the drill?
Do you think I'm barking up the wrong tree with the valve guides? The new valve stems were too slack I reckon, but I didn't check them for sure with the test dial. Big regret, but thought new seals would be enough.
valves should be ok as long as the have good seals, it helps with a slowish adjustable speed drill and practice a comfortable arm movement you can replicate easily enough aim for 45 degrees between the 2 intersecting lines,it doesnt matter too much if you dont get it spot on to start with as long as there enough at the finish
 
valves should be ok as long as the have good seals
I knew you were going to say that. :) The seals were new Elring ones
it helps with a slowish adjustable speed drill and practice a comfortable arm movement you can replicate easily enough aim for 45 degrees between the 2 intersecting lines,it doesnt matter too much if you dont get it spot on to start with as long as there enough at the finish
That sounds easy enough for you :rolleyes: :D Obviously, you'll be able to tell I'm not relishing the idea of doing it. Is it possible to adversely affect the bore diameter? IIRC you previously said that you only need to do about 15-20 strokes, or am I making that up?
 
youd struggle to take that much out,, you need to do as many stokes gives a good finish and use a very thin oil or paraffin lube/wash it helps if someone can keep giving a squirt as you hone it
 
youd struggle to take that much out,, you need to do as many stokes gives a good finish and use a very thin oil or paraffin lube/wash it helps if someone can keep giving a squirt as you hone it
Ok, great. By paraffin lube, do you just mean paraffin in a squirty bottle?
The engine has now done 8.5k miles since the rebuild, so I would have hoped it would have settled down by now if it was going to. looks like I might need to bite the bullet when the weather warms up.
 
Sorry, James. I still don't get it. How is the oil getting past the rings by being dragged up? :confused: Will the scraper ring not be stopping that?
only if honing is correct , apart from been true and sized surface needs to be right,obviously rings are vital too
 
only if honing is correct , apart from been true and sized surface needs to be right,obviously rings are vital too
Ok, James. Sorry for harping on. There's two things going on in my head:
  1. Trying to understand how it's happening
  2. Clutching at straws that it's not the problem :)
Ha, ha, obviously it the second one I'm hoping to find some evidence for. :rolleyes:
 
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