2.5 n/a diesel - interference or not?
2.5 n/a diesel - interference or not?
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airbrakes

Original Poster:

10,709 posts

184 months

Monday 26th August 2013
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Evening all, I'm trying to advise someone on a Landy facebook page. He has bought a non-runner 2.5d n/a with unknown history and a snapped timing belt. He is of the opinion that the engine has done what TDi's do and snapped its timing belt, giving all the usual piston/valve interface problems.
However, I was pretty sure that the 2.5, being essentially a bored out 2.25, is still non-interference like the 2.25? Therefore if the belt has snapped there should be no damage, right? (AFAIK, it was the totally new head design of the 200Tdi that turned it from non-interference to interference valvegear?)
Wrong - he has taken the pushrods out and they are all spectacularly bent shapes. He says this is proof that it has "done a TDi", but I'm not sure at all. I am Increasingly thinking the engine has been hydraulic'd, the sudden halt to rotation being what bent the rods and snapped the belt?

Can someone confirm either way?

Thanks!

camel_landy

5,418 posts

207 months

Tuesday 27th August 2013
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The engines are still very similar and I'm fairly sure you'll still get the crown hitting the valves if the belt lets go. However, there's a good chance there hasn't been any internal damage, so you'll be able to just get away with replacing the push rods.

M

hidetheelephants

34,262 posts

217 months

Tuesday 27th August 2013
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Hydraulicking would be unlikely to snap the belt unless it was about to snap anyway; how in the wide world of sports do you have a non-interference diesel? That's a trick I'd pay to see.

malman

2,258 posts

283 months

Sunday 1st September 2013
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AFAIK when the belt goes the valves will meet the pistons but because the valve are perpendicular to the piston they stay straight and the load gets transferred to the push rods mostly. You can end up with damage to the rockers etc.

The pistons and valves should be ok so it shouldn't need the head removing to sort it out. You need to check push rod seats and make non of the rockers have cracked