Saintsman From United Kingdom, joined Mar 2002, 2065 posts, RR: 2 Posted (6 years 1 month 1 week 3 days 17 hours ago) and read 952 times:
My daughter's Peugeot 306D cam belt broke at the weekend. She doesn't have much money for repairs so I'm sure she will come looking for me.
Does anyone know whether the engine will be okay (just a new belt) or will it have damaged the valves? Being diesel I'm hoping the valves will be set above the pistons and won't have done any damage.
Saintsman From United Kingdom, joined Mar 2002, 2065 posts, RR: 2 Reply 2, posted (6 years 1 month 1 week 3 days 16 hours ago) and read 925 times:
Quoting Superfly (Reply 1): Did she try to restart the engine?
I'm afraid she did, though she said that it wouldn't turn over. I can't work that one out though as it should have turned the bottom end. She doesn't live near me so I can't look at the car myself. She'll be at the mercy of a local garage.
Superfly From Thailand, joined May 2000, 38514 posts, RR: 80 Reply 3, posted (6 years 1 month 1 week 3 days 16 hours ago) and read 915 times:
Quoting Saintsman (Reply 2): I'm afraid she did, though she said that it wouldn't turn over. I can't work that one out though as it should have turned the bottom end. She doesn't live near me so I can't look at the car myself. She'll be at the mercy of a local garage.
YIKES!
This is how it usually happens. When timing belts/chains break, the driver doesn't know it instantly. The car just shuts off without warning and naturally try to restart it. That is when the valves get warped.
Let's hope that is not the case. Are you sure here timing belt broke?
I can recall one time where I thought my timing chain had snapped but it was actually the control module that was no good. It was only a $32 part to replace.
DesertJets From United States of America, joined Feb 2000, 7673 posts, RR: 18 Reply 4, posted (6 years 1 month 1 week 3 days 16 hours ago) and read 906 times:
You need to figure out whether or not the engine in her Pug is an interference engine or not. That will make the difference between the cost of a tow and a new timing belt, and a top end overhaul.
Best bet to figure this out is look up her car in Wikipedia and see what info they have on that particular engine.
And let it be a lesson that maintenance items like timing belts need to be replaced when the owner's manual says so.
Stop drop and roll will not save you in hell. --- seen on a church marque in rural Virginia
Bongodog1964 From United Kingdom, joined Oct 2006, 3019 posts, RR: 2 Reply 5, posted (6 years 1 month 1 week 3 days 16 hours ago) and read 904 times:
If its an engine where the valves at full open protrude below the position of the piston head at top dead centre; they will have destroyed themselves nicely at the time of the belt breaking, as the camshaft and crankshaft will quickly run at differing speeds.Any attempt at trying to restart the engine will make no difference to the outcome. Any restart attempt would likely (as in this case) fail to turn the crank, as the valves welded into(onto) the pistons will stop it moving.
Falstaff From United States of America, joined Jun 2006, 5673 posts, RR: 29 Reply 6, posted (6 years 1 month 1 week 3 days 14 hours ago) and read 852 times:
Quoting Superfly (Reply 3): This is how it usually happens. When timing belts/chains break, the driver doesn't know it instantly. The car just shuts off without warning and naturally try to restart it. That is when the valves get warped.
Partially true, but the cam will still spin for a moment and the pistons will still go up a down so bashing the valves is a real possibility.
Quoting Bongodog1964 (Reply 5): Any restart attempt would likely (as in this case) fail to turn the crank, as the valves welded into(onto) the pistons will stop it moving
I have seen that happen many times. For as often as I have seen that I have also seen the valves get bent and the pistons are ok.
Diesel engines are very high compression so it is very likely that the engine is an "interference" engine.
Quoting Saintsman (Thread starter): Being diesel I'm hoping the valves will be set above the pistons and won't have done any damage.
Being a diesel the chances for serious damage are increased. The pistons have to compress the air very tightly so when the fuel is injected the combustion can happen. The tighter the compression the closer the pistons will get to the top of the combustion chamber, thus being closer to the valves. I can't give you any specifics because those are not sold in the US and I have never worked on one. Just speaking from experience.
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