I took my car to Shakespeare county drag strip this weekend , on Saturday car done well considering a complete new setup 12.9 with no gas , but on the last run, tried some gas from second gear as i crossed the finish line and came off the throttle, noticed the revs still coming up shut it off . The pipe from the intercooler to the inlet manifold was off , so was all the other pipes on the inlet and the seals for the injectors blown out , i think i had overboosted . When i put the pipes back on there is a top end rattle . When start up from cold its quiet for about 2 mins then it starts to rattle, does anyone know what this could be and how to fix it?

Did you break the upper timing chain guide off? Take the valve cover off and check it out.

Ill take the cover off and check this , would it be obvious to see if this was broken ? I was thinking it might be a lifter but im not sure if what ive done would cause a damaged lifter

If it was a lifter it would be more of a tick not a rattle. The guide is mounted in the middle and just behind the two cam gears. Its in the shape of a T and secured by two bolts. Nissan actually states you no longer need to run this piece. So if you find it is broken just remove the broken piece, do a good inspection for any possible damage done and remove the base and two bolts still attached to the head. Also if it is broken its probably a good time to replace your timing chain tensioner.

Thanks for the replys , ive been busy with work and not had a chance to get a look yet . When i do ill let you know what i find .

I took my mate Andrew Baird, the mechanic round to see my car last night . The car had been sitting for around a week so it was started from cold. It sat idling for a couple of minutes, as has happened in the past, I told Andrew it would start to make noise soon . It came up to temp with no noise from the top end , I was quite suprised although very pleased.

Andrew explained what could have possibly happened; when i've been at full throttle crossing the finish line, it's overboosted and when the pipes have blown off the inlet manifold it's turned to max vaccum and sucked oil from top end ie the lifters.

Whats your opinion on this? I started it up the next day and everthing seems fine even under boost . Andrew's going to do a leakdown test on Friday so i'll put results up .