Simon Posted December 17, 2007 Report Share Posted December 17, 2007 Well, I was going to an appointment this morning when I suddenly hear a loud bang from the motor. I realize that I lost about 75% of the power and the big bang is occcuring at every rotation of the motor. Still don't know what it could be...I made a search but came up with nothing similar. Had the truck towed. To start the motor back, I needed to give close to full throttle to get it going and then it would die and not idle. All that with the great bang. I was thinking it would be a valve that fell in the cylinder but i'm not sure anymore. I think it's more from the bottom... Does anyone know what's happening? Quote Link to comment Share on other sites More sharing options...
Rausche Posted December 18, 2007 Report Share Posted December 18, 2007 Something collapsed. Sounds to me like a problem with either the crank or the camshaft (especially if it happens with every rotation)... I'm sure someone else has a more knowledgeable opinion, but I would NOT try to start it until you know what the problem is, you'll more than likely end up doing more damage the more it runs. FWIW I would say you collapsed a pushrod or the camshaft failed in some way... Quote Link to comment Share on other sites More sharing options...
zippy Posted December 18, 2007 Report Share Posted December 18, 2007 Sounds to me like you're another one to have a 918 Comp Cam's spring failure. If I had to guess, that would be what happened. Quote Link to comment Share on other sites More sharing options...
Fireman31 Posted December 18, 2007 Report Share Posted December 18, 2007 sounds like you broke a valve spring, valve, or pushrod..........could even be a spun bearing Quote Link to comment Share on other sites More sharing options...
Krambo Posted December 18, 2007 Report Share Posted December 18, 2007 Could be anything. I'd start with the easiest and pull the plugs to isolate if it is one bore or the other. You may not like what you see Quote Link to comment Share on other sites More sharing options...
detjoe Posted December 18, 2007 Report Share Posted December 18, 2007 or pull the valve cover, to see if the springs are ok? sucks...knock on wood for you (and My) 918's. It would just suck if those started breaking more on guys. Quote Link to comment Share on other sites More sharing options...
gs430 Posted December 18, 2007 Report Share Posted December 18, 2007 That sucks.Hope you get your truck running again. Quote Link to comment Share on other sites More sharing options...
Simon Posted December 18, 2007 Author Report Share Posted December 18, 2007 Thanks for your support guys! I heard that there would be a recall from Comp Cam is that possible? I know now that it is from the top we'll se as the covers are removed... Quote Link to comment Share on other sites More sharing options...
misterp Posted December 18, 2007 Report Share Posted December 18, 2007 Thanks for your support guys! I heard that there would be a recall from Comp Cam is that possible? I know now that it is from the top we'll se as the covers are removed... Pull the plugs first, you'll find the offending cylinder. If there was a loud dramatic bang then something is seriously wrong, I would expect the worst like yeah swallowing a valve. But that would be the fault of the retainer, not the spring itself. Mr. P. Quote Link to comment Share on other sites More sharing options...
detjoe Posted December 18, 2007 Report Share Posted December 18, 2007 yea comp will give you a new set??? doh keep us posted. Quote Link to comment Share on other sites More sharing options...
rivierakid55 Posted December 19, 2007 Report Share Posted December 19, 2007 theres supposed to be a new updated spring kit from comp that dealt with this problem. dont have the pn unfortunately. Quote Link to comment Share on other sites More sharing options...
FireRescueSS Posted December 19, 2007 Report Share Posted December 19, 2007 All I can offer you is my appologies, and hopes your back up and running soon. Quote Link to comment Share on other sites More sharing options...
dozer Posted December 20, 2007 Report Share Posted December 20, 2007 Comp cam has recalled all 918 springs with batch numbers listed below. Call Chris Mays at Comp Cams at 901-795-2400 extension 505 or [email protected] and they will next day updated springs. I just installed mine 3 month ago batch #049045. They will be coming out shortly. 1) 49253 2) 049045 3) 49826 4) 050808 5) 051791 Quote Link to comment Share on other sites More sharing options...
Simon Posted December 20, 2007 Author Report Share Posted December 20, 2007 (edited) Just came back, it is a spring that broke and the valve is broken in two and all the parts are stuck in the head...the piston has the side of the valve nailed in and the cylinder is marked pretty bad. I think I'll need to oversize but don't know how much. how much oversize is needed for a 370 and for a 408 and what kind of piston or overhauled stuff I need? Edited December 20, 2007 by Simon (see edit history) Quote Link to comment Share on other sites More sharing options...
riddle Posted December 21, 2007 Report Share Posted December 21, 2007 Just came back, it is a spring that broke and the valve is broken in two and all the parts are stuck in the head...the piston has the side of the valve nailed in and the cylinder is marked pretty bad. I think I'll need to oversize but don't know how much. how much oversize is needed for a 370 and for a 408 and what kind of piston or overhauled stuff I need? .030 is what your lookin for! Need to know more about what you want the truck to do for you, to determine what parts you would need. JE offer's flat top and -29 dish. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.