ok have you ever heard of this with a G50 Q45 engine

[mechanikdan]

i got a nice 1993 Q45 from a customer with a jumped timing issue. the car cranked like you took the pistons out of it. no fire, no weird terrible noise, no nothing. Just crazy fast cranking like no compression. We pulled the engine and ordered another junk yard low mile 87k engine and prepared to swap them. Just for the heck of it we took the front cover off the old engine and found only one 1/2 inch section of the drivers side rail at the top missing and all other pcs in ok shape. We did find the hydraulic tensioner to have very low tension. We took the heads off and no marks or damage to the pistons. THe valves have no marks on the carbon caked on them but we will check for straightness. What the heck. tensioner just died at start up and timing jumped but nothing got damaged. Anyone heard of this.

Im not complaining

[Q451990]

Did you happen to notice how many teeth it jumped? I have heard that one tooth is possible without damaging anything. Two and it's not good. When I lost my guides on my old Q I had one valve slightly bent on one cylinder. I think a lot of it depends on how hard the engine is running at the moment the timing jumps. Do it at redline and you've probably knocked every valve through something... in my case it was pulling away from a stop light, and then a minute of idling with lots of shaking and backfiring while I stupidly stood there looking at it to see if I could figure out what happened.

Heath

[elwesso]

sounds like you could just clean everything up and retime the engine....

[mechanikdan]

it was four or five off so i am betting on a few bent valves but i was expecting holes in pistons.........plesantly suprised.... got a 94 low mileage engine for sale now...lol