lester Posted September 13, 2010 Share Posted September 13, 2010 so after a summer full of problems for my z we finally got it running. we took off the head to find a bolt stuck in the head between one of the valves.. there was no damage to the pistons luckly. we bought a new head for the car, and decided to go with a new header for the exhaust as well. we got it all together and it ran great.. its been my daily driver now for the past month. i am currently a freshman in college and live about 40miles from home. today on the way back to college from my house the engine began to knock. i stopped at a gas station and popped the hood but couldnt tell exactly where the knock was coming from. i dont use my car often, just to go home on the weekends. it has about 400 miles on it sense we replaced the head, and we planned on changing the oil at 500... what could be causing this knock? it scares me that we bent another rod in the head.. i sure hope this isent the problem.. but does anyone have any ideas where this knocking could be coming from? Thank you Quote Link to comment Share on other sites More sharing options...
Powerglide Posted September 13, 2010 Share Posted September 13, 2010 The knock could be coming from the timing chain, the main bearings, the rod bearings, the valves, or the rocker arms. Or maybe the a/c compressor, the transmission, or the clutch. Quote Link to comment Share on other sites More sharing options...
lester Posted September 13, 2010 Author Share Posted September 13, 2010 i think i can rule out the clutch or tranny.. it sounded like from the motor but i couldnt tell exactly where from.. it didnt start making the noise till i got all the way to where i was going...sorry its kinda a non specific post but im just worried and wanted to c if anyone had some ideas.. im gonna start it up tomorrow after classes and c if the knock is still there Quote Link to comment Share on other sites More sharing options...
jbehuniak Posted September 13, 2010 Share Posted September 13, 2010 What engine is in the Z and head combo... from saying another bent rod I'm thinking push rod? If its an L6 it would help if you isolated what type of knock it is, just at idle, revving the engine, after a long drive like ignition knock? The head normally just ticks. Did you get to look at the head, cam and tappets (Saab terms sorry) to see if there was any scoring? How is the oil pressure? It wouldn't show much unless one of your bearings is realllly loose or has spun. Quote Link to comment Share on other sites More sharing options...
lester Posted September 13, 2010 Author Share Posted September 13, 2010 not sure on the engine but know its an n47 head. its stock. im going to go start it here in a few minutes and see if i can find where the knocking is coming from. ill give you an update once i go out Quote Link to comment Share on other sites More sharing options...
lester Posted September 13, 2010 Author Share Posted September 13, 2010 so.. just went out and started the z. it ran great, and the loud knocking sound i heard last night when i got here was gone... there was a slight ticking noise coming from around the head. so when it comes down to it, it doesent get louder until i drive farther than like 45 minutes. what could be causing the noise? could my valves be out of adjustment? oil pressure was great when i started it, right in the middle of the gauge like usual. thank you everyone for the help. Quote Link to comment Share on other sites More sharing options...
jbehuniak Posted September 13, 2010 Share Posted September 13, 2010 After it gets louder, what is your coolant temp? And can you get a infra-red thermometer and point it toward your head. If you have alot of advance in your car or are running too lean once your coolant heats up enough it will start to steam inside your head and cause preignition/ detonation which can sound like something is loose. Quote Link to comment Share on other sites More sharing options...
lester Posted September 13, 2010 Author Share Posted September 13, 2010 i usually dont drive my car for more than five miles when im on campus. i wont know until i drive home in a couple weeks to see what the temp is at. im pretty sure it was normal and about at the middle. pretty sure its something under the valve cover, and hopefully a simple fix Quote Link to comment Share on other sites More sharing options...
sticky280zx Posted September 13, 2010 Share Posted September 13, 2010 sounds like you need to adjust your valves, and if you are running higher or advanced timing premium gas is a must. Quote Link to comment Share on other sites More sharing options...
lester Posted September 13, 2010 Author Share Posted September 13, 2010 yea thats what we figure wed do when i go home. i run nothing but premium gas in it. and i hope your right about the valves Quote Link to comment Share on other sites More sharing options...
lester Posted September 15, 2010 Author Share Posted September 15, 2010 so i decided to take it to practice today, a short mile trip there and back. It started fine and sounded normal. a little ways down the road it started clicking again...and it was loud. i have a video on my phone, but it wont let me upload it. if anyone wants to see the video juss pm me and leave your number and ill send it. im going out to get a socket set tonight so i can look under the valve cover. it defintly sounds like its coming from the head. also did a spark plug wire test while i was listening to it. it seemed like it died some when i pulled the middle four wires, but the first and sixth plug wires seemed to not have much effect on the running of the motor. could my valves have come that unadjusted or is there another problem here? its starting to become very stressful because this cars my baby, but if i need to put another head on it, ill have to get rid of her. someone please help Quote Link to comment Share on other sites More sharing options...
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