Hi guys, just wanted to introduce myself a bit... I was into auto mechanics for 10 years professionally and all my life non-professionally. I have rebuilt about a dozen motors with good success, dont what seems like thousands of repairs. I have never had a problem I couldn't figure out without some persistance.. Until now.....
I have a 104K mile corolla 1.6L auto that was owned by a 70 year old lady most of its life...
I bought it as a no start, starter wouldnt turn for low-money and assumed it was probably a starter and timing belt or maybe just a starter...
Well, I fixed the starter and got it running. It runs like a top.. but ticks... ticks loud enough to make people look at the car.
It sounded to me just like a sticking lifter in an old chevy v8 or a loose rocker arm sound... tap tap sound coming from what seems about the middle of the engine, just about at the bottom of the head or top of the block..
After getting second opinions on the sound I convinced myself it was a rod bearing, so without much thought I pulled the pan and got into it... I found worn bearings but not enough to make noise on one rod... I put new std size bearings in anyhow...
After startup it still makes the same sound.... So I pulled plugs and noticed quite a bit of carbon. I decided to seafoam it thinking maybe there is extreme carbon buildup in the head which I have heard can cause a similar noise to rod bearings. It makes the noise at idle pretty much up the whole rev range, the engine reving just about drowns out the noise at high rpm.
I put through the course of the day 2 cans of seafoam through a vacuum hose... Every time getting big white clouds of smoke.... as it was sucking the seafoam in it seemed like the noise was disappearing but I didnt know if it just seemed that way cause the rpm was lowering.
Then put 1/2 can in tank and premium gas and drove about 50 miles... end result is the sound is exactly the same. I am not 100% convinced that the carbon isnt the problem... but after no change in thinking it may not be...
I am now thinking maybe it could be the valve lash... which of course is a biatch to adjust since it requires shimming. I pulled the valve cover off and randomly checked a few valves with my feeler guage getting satisfactory readings based on the sticker on the hood. I guess its still possible that the noise may be one valve out of spec, however the sound just doesnt seem like its coming from that area.... seems a bit lower... I may be wrong.... Only other thing I can think of is a bad wristpin??
I keep going back to the carbon issue though considering its long term old lady driving habit....
Please anyone with ideas, or suggestion as to how to quiet this thing down.... PLEASE chime in....
The oil pan was free of metal particals, the top end under valve cover was exceptionally clean and grime free... The motor runs and purrs like a kitten, smooth as can be but one valve or piston goes tap tap tap...
do a compression test. Run some trans fluid in the crankcase for 100 miles and change the oil. Or sea foam it. Probably neglect to change oil is the issue.
Ran some more seafoam, changed the plugs and added 1/2 can to oil of seafoam and drove another 50 miles... At times it quiets down for about 20 seconds of so almost completely.... some times its louder...
Last edited by sharker2000; 10-07-2009 at 05:32 PM.
It certainly sounds mechanical, like something being loose and hitting against something else. With regard to lifters here are some specs:
Lifter diameter 1.2191 to 1.2195 inches
Bore diameter 1.2205 to 1.2215 inches
Lifter oil clearance
Standard 0.0009 to 0.0023 inch
Service limit 0.0028 inch
Perhaps the camshaft gears and/or sub-gear spring could be the problem? Causing excessive backlash on the camshaft. Quite a longshot I suppose, but I am just trying to think of stuff that could potentially be loose in there.
Wow this is crazy....
I pulled the intake cam and checked the gear spring, seems to work fine, pulled see clip and measured opening and all within spec... all lifters and valve clearances are spot on, no sign of any scum buildup on any internal parts...
The noise sounds like its coming from the middle of the block in back under the intake 2 or 3 cyl and about right on the top of the bottom end...
I tried the water in the intake steam trick to try to clear out what I thought might be carbon and all I notice is when it seems to skip while adding water or seafoam the noise goes away. I am thinking its temporarily fouling the problem cylinder and quieting up... yet if I try pulling plug wires while running one at a time it doesnt seem to quiet it down...
The noise is worse when cold and varying when warm from almost not there to almost as loud as when cold.....
The only logical thing I can think of is a wristpin? I would really like to figure this out as its bothering me.
Its definitely loud enough to be something that needs to be fixed. Lets go back to the original starter problem... Did you change or mix mounting bolts? Maybe one os too long and hitting flywheel at one spot?
Its NOT a rod knock. You confirmed that in the video when you revved the engine.
Have you done a leakdown test to make sure you dont have a bent valve that is hitting the piston? This night happen if your valve timing is off as well.
I appreciate the time you guys are putting in to thinking about this...
As far as the starter... I hit it once with a rock and it started up and hasnt faulted since... never changed it...
I know its not a rod knock because I replaced the rod bearings....
Bent valve..... I would think it would run less than perfect.... and would not my cam to valve clearance be off?
Timing off..... This is interesting.... do you think a stretched timing belt could make the timing be off just enough to maybe let a valve tap a piston?? Looking at the timing belt it appears to be the original considering it says toyota on it, although if it was changed or bought at the dealer it would say toyota too, but its definately not brand new.... it looks well used.... Actually thinking about it more since it is not an interference engine I guess that wouldn't be possible....
Hi there, I also have a 4afe in a 1995 toyota trueno. I have found that when I replaced my cambelt was told by one of the mechanics that a way to see if your cambelt has been replaced in the past, the right hand side nut on the cambelt cover is missing due it being very difficult to re-insert it.
if yours is missing it would most like have been replaced in the past.....hope this helps
Regards James
its either the third or second right hand side arrows.
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Corolla 93 1.6l 89Kw DIY mods 
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