Starting an old engine

[Marks 110]

I'm going to fit an old disco 200tdi block into my defender. I've had it lying around in my garage for a while and it was sat in a scrapyard for some considerable time before that. Mileage and condition unknown but it looks ok and turns over smoothly.

As I'd taken the head off it to lend to a mate the bores have gone a little rusty, should I try and clean them up before refitting or will the action of the rings clean it off?

Also I'm a bit worried about starting it up as I've heard horror stories about tdi's running on their own oil. What precautions should I take?

Mark

[Les Henson]

I wouldn't leave the rings to clean the rust off - iron oxide is very abrasive and it would end-up elsewhere in the engine before finally being filtered out. Clean the bores with 1200 wet/dry, with WD40 or a very light oil. An engine running on it's own oil is down to sticking rings, excessively worn bores/pistons, Oil entering the bores by other means. It's a bit unlikely that the the engine will run away just because it's been stood for a while. You can be prepared for it however - get ready to block off the inlet manifold, or stall the vehicle if it happens.

Les.

[Marks 110]

I wouldn't leave the rings to clean the rust off - iron oxide is very abrasive and it would end-up elsewhere in the engine before finally being filtered out. Clean the bores with 1200 wet/dry, with WD40 or a very light oil. An engine running on it's own oil is down to sticking rings, excessively worn bores/pistons, Oil entering the bores by other means. It's a bit unlikely that the the engine will run away just because it's been stood for a while. You can be prepared for it however - get ready to block off the inlet manifold, or stall the vehicle if it happens.

Les.

Cheers Les will let you now how I get on.

Mark

[Marks 110]

Cheers Les will let you now how I get on.

Mark

Thinking of nipping out to machine mart and grbbing a cylinder hone as I'm still not happy with finish of the bores. Any tips for using one. Will I have to fit new rings (there not cheap, best part of £20 inc.vat from Turners) or will the old ones bed in ok?

I'm guessing new rings.

Mark

[Les Henson]

A 3-bar cylinder hone won't make the bores round (they wear slightly oval due to the thrust side of the engine.) I wouldn't use one while the pistons are in it either - the hone wears as it removes metal/rust, so there will be abrasive particles in there still. To measure piston ring wear - you have to remove the ring, push it 2/3 way down the bore with an inverted piston (to make sure it's square in the bore), then measure the ring gap. £20 for a set of rings is a reasonable price - you are in effect getting 12.

To use a cylinder hone - you use them with oil (I use WD40). Insert the hone in the bore, then start the drill. Move the hone slowly up and down the bore all the time the drill is running and replenish with oil as necessary. A picture of the pitting would be helpful?

Les.

[Marks 110]

A 3-bar cylinder hone won't make the bores round (they wear slightly oval due to the thrust side of the engine.) I wouldn't use one while the pistons are in it either - the hone wears as it removes metal/rust, so there will be abrasive particles in there still. To measure piston ring wear - you have to remove the ring, push it 2/3 way down the bore with an inverted piston (to make sure it's square in the bore), then measure the ring gap. £20 for a set of rings is a reasonable price - you are in effect getting 12.

To use a cylinder hone - you use them with oil (I use WD40). Insert the hone in the bore, then start the drill. Move the hone slowly up and down the bore all the time the drill is running and replenish with oil as necessary. A picture of the pitting would be helpful?

Les.

Rings were nearly £20 per piston! Mind you theres only one bore where the rust is bad (there must have been water sat in there at some time) so I think I'll just do this one. I'll take a picture but I've never managed to get one uploaded in the past.

Mark