Well, here I go again with my **** luck. Car recently started making a ticking sound like a loose or bad rocker. Last year I had Crane Gold 1.6's and new 103-08 springs installed just 3K miles ago. They were replaced during dyno tuning due to the stock valvesprings not holding enough pressure and allowing valve float (at a mere 41K miles with very little abuse ). My mechanic inspected the rockers and found no problems and determined that the sound was coming from the lifters, he said it sounds exactly like a collapsed lifter. The fact that the car had valve float made the idea of a collapsed lifter even more probable. So I get the lifters and he installs them, meanwhile he inspected everything and said the lifter valleys looked fine, the rods looked good, and the old lifters had no visible damage (therefore the cam should be fine, OEM cam). He fires it back up and the damn problem is still here. He has narrowed it down to the same exhaust valve because he said he made sure he rearanged the pushrods and rockers and the noise is still coming from the same valve. Also he said something about being able to hold a wrench on the rocker and the noise goes away.....as soon as he lets go of it it's noisy again. It is quiet when cold and only makes the noise when it's warmed up. The engine runs smooth as butter. Once it warms up it becomes rather loud and sets off the knock sensor even just reving it in neutral. He thinks it might be the valve itself but isn't sure what to do next. Any ideas?

 

Maybe loose or cracked valve guide? Dunno just throwing something out there. Can't think of anything else if he's isolated it to a specific rocker.

 

rocker stud or valve guide problem.

 

Rocker stud was my guess but he seems to think it's not the problem. Educate me a little, the valve guide will require pulling the heads to replace but the rocker stud will not ....correct?

 

Checked into something as simple as an exhaust leak yet?

 

I wish it was an exhaust leak ......

 

you wont have to remove the heads for stud replacement, but if you have to repair the thread then you may have to. for valves guided you will have to remove the head.

if it were an exhaust leak i dont know why it would go away by holding the rocker stud with a wrench.

 

gah, sorry, missed that part man...

 

I don't think a valve guide would make a ticking sound right... it's merely a sleeve to center the travel of the valve. If a wrench on the rocker arm stops it then you have narrowed down the problem already. Pull the valve cover and pull that rocker and pushrods and inspect the area. Make sure the stud didn't back out for some reason and that the threads are still good. You should be able to helicoil the hole with the head on the car... put some grease on the grooves on the tap to catch any metal and you will be fine (assuming that's the problem).

Do you have the rockers that have a machined groove for the nut to tighten into? I know my comp pro mags do and if you don't have the rocker on the right way it will make noise. Check the roller on the rocker to make sure there is no play and that the bearings are still good. I would also check that pushrod by rolling it on a table or something, just to rule it out.

It would help if you had a mechanics stethoscope to pinpoint the sound. You stick that little probe onto the parts you think are ticking and you will be able to tell what it is and then go from there. That's all I can think of charlie, good luck.

 

Charlie,

The fact that it only does it only when it's warm pretty much eliminates the possibility that it is a stud thread, pushrod, or rocker related problem IMO. Nothing about those (3) components changes with temperature, and warmer, thinner oil wouldn't affect them either.

A guide, particularly an exhaust guide sounds like the problem. If that guide were starting to gall a little, it could be keeping the valve from returning fully to the seat which would introduce additional lash into the stack of parts. That could also be affected by temperature as the cold valve could have enough clearance in the guide not to stick, but as the valve heats up, it would reduce the clearance perhaps enough to stick just a little. The only thing that doesn't fit that theory is it would lower the compression in that hole, and should make the engine less smooth, but having one hole that is only a little low is not always apparent to the observer.

The test would be to put that piston at TDC, and remove that spring. You should then be able to move the valve freely in the guide. If it's galled, you'll notice. I would perform that test with it warm.

Rog

 

Another vote for an exhaust leak.

 

Thanks for the tip Rog. He is planning on removing a spring if necessary but dreads it, as it's a PITA with the headers. BTW, congrats on the 11s !

 

I had a simlar problem like this and found out it was the air pump that supplies the air to the cats. As funny as it may sound I tsound like it was coming from the valve train area. May want to look in to this. I do see you said you had headers so maybe you removed this stuff. If that was the case I would look for a header exhaust leak.

 

I have the same problem going on. I noticed a tick coming from the passanger side . Pulled the valve cover and number 8 exhaust roller rocker was siting sideways. Rocker was trashed. Replaced with an old GM roller from an old setup and relashed the valves. The noise was still there. Replaced the pushrods and lifters with the same results. Will pull the valve spring and check the guides. And as above the noise gets louder as the car warms up but it runs great and does not miss.

HVY SS

 

Well, he seems to agree with you all ....that is is likely a valve or valveguide problem (number 6 exhaust valve). He says the rocker stud is absolutely fine. This will require pulling the heads regardless .....so the cost of that is obvious . He has some year-end cart racing to tend to so he won't be able to work on it until after Christmas. Gives me some time to think anyway. I am considering rebuilding the damn motor while we're at it. He said he'd port the heads for an extra $100 ~ $150 if I want. I'm kind of thinking if the intake and heads are off lets just do a budget rebuild while at it .....thing that sucks is this thing has like ~43k on it and has had relatively little abuse. I've only had the supercharger on since 38K and have had a permanently mounted Scanmaster in place to make sure I don't drive it into knock and/or lean conditions ......damn it, what good does it do? Try to save the pistons and wind up eating a valve anyway ....what a bunch of bullsh!t.

What do you all think, should I just fix it and go on? ....or, should I dip into savings (I'm 32, that sucks) and throw in some forged pistons, ARP rod bolts, custom blower cam, Meziere waterpump, 5.85" forged rods, forged pistons, Street Twin, etc .....and then, "go on". (yes, 12-bolt and 75-shot in near future too)

Downside is..... I really didn't anticipate doing all of this now (more like two to three years from now). But I'm thinking, hell ...if the headers, heads, and intake are all off anyway .......it's less expensive now than later. Plus I may have to do it all in the near future anyway, especially the way my luck goes (example, put it all back together and then a piston goes on my next 1/8 mile run ....seriously, that's the type of thing that would happen to me).

The plus side is having cam/heads and the extra power/sound that comes along with it......along with the reliability of forged internals.

I already have the supporting mods (42# injectors, inline fuel pump and AFPR, new 1.6 RR's and springs, new lifters, long tubes, etc)

Suggestions? :blah: