I think I am cursed or something.

Today on my drive home, my engine started ticking loudly and mis-firing. I noticed it and pulled over to check it out. Coming from the driver side. Well I was over 20 miles from town/home out in the desert. I had to drive it home. It ran ok short of the noise and occasional misfire/backfire through the carb.

So I got home and pulled the plugs and valve cover. Plugs looked fine, nice and tan and clean. Valve cover off revealed nothing. I started it for a few seconds and watched the valve action. No visible problems.



About 500 miles ago I switched jets in the carb, leaned it out a bit in hopes of better mpg. (I have to drive over 70miles a day) I gained 2mpg, but it was definitely on the lean end of the spectrum.

Based on that, I'm worried I burned a valve, or sank one in the seat. But I don't know yet...



Expert advice and input wanted!

 

sorry to hear did you do a compression check ?

 

Not yet. Ran out of daylight and had to find another vehicle to borrow. I'll have a few hours tomorrow to do a compression and leak down test.

 

Ah the come back kid returns scratching himself in aw WTF is it now?

But you said the plug was tannish that don't sound like being to lean.

Put your hand over the carb air horn while it's running at idle and slowly cup your hand closed. If lean the motor will increase rpms. If not then the motor will load up slowly die from being to rich..

You know lean would ping rattle and lack of high speed power, This is when a manual choke comes in handy if lean pull choke out a little and your good to go..
Orich

 

I don't think I was running it TOO lean. I jetted The carburetor to Edelbrock's recommended fuel economy size. A 98 jet with a 75 rod. Which equates out to about a 63 jet normally. Still running 95's in the secondaries. It ran good, but there were starting to be drivability problems, so I didn't want to go any leaner.

 

Easier than doing a compression test or leak down test...connect a vacuum gauge to the manifold, if it flutters it is indicating poor valve sealing. Then do a leak down test to pinpoint which valve is having the problem.

 

I have a vacuum gauge in my dash. It does flutter. That is what is tipping me off to a valve problem, as well as the excessively loud, solid ticking

I am hoping it is just a locked up hydraulic lifter. I have had that happen once before and it was doing about the same thing if I remember correctly

 

Is this the same motor that bent the push rod? this may be the culprit that caused that.

 

It is, but that was on the other side. No problems on that side. And it's nice and quiet.

 

You may have a broken valve spring, sometime it is hard to see, turn the engine over by hand and push on each rocker arm when the valve is closed.

 

I will check it out. Thanks Kenny

 

Did you start it with the valve cover off and isolate the noise? Do this while cold and put towels down to catch any oil.
See where it is coming from exactly.
Could be any number of things but I'm thinking you might have purchased a bad set of push rods considering it happened before.
Spring, rocker arm, even a lifter could do this.

If you isolate the noise that'll help.
Do this with the engine cold.

Just sayin.

 

I'll check, but I highly doubt the pushrod went bad. They are comp cams magnum pushrods. 3/8 diameter .080" Wall.

 

My 1st reaction was another broken spring. Fire it up with that valve cover off. Carefully put your finger or a pair of fingers on each rocker arm. You'll be able to "feel" that tick you're hearing. That tick is prolly on either or both ends of the pushrod. If it's a broken spring you know what you're looking for. Or maybe a collapsed lifter.
You weren't doin' a 8000 RPM burnout just before this were ya?

 

I think I found it. #5 exhaust lifter looks like it has a HOLE in it. Like the pushrod went through it.

So I'm tearing it apart. I'll let you gents know what I find.