al02gt

02 Gt- This knock started after I replaced the car blew out #4 and I replaced the timing chains. I took it back apart and made sure everything looked good and the dots were lined up.

The first time I may have had it one tooth off, because I marked the cams instead of using the dots to line everything up. I rotated the crank before starting both times and didn't have any interference.

http://packetfocus.com/mustang/gtnoise.wma
(Laptop sitting on radiator so it makes it sound a little lounder than it really is)

SO now the car has a rattle at idle. After you start it, it takes about 10 seconds for the rattle to start. It also seems to go away when you give it any throttle.

The car runs great with no hesitation, pops, or skips. Gauges are good and the exhaust doesn't smoke.

Any ideas? Is this something I could have done by getting it one tooth off?

If a valve was damaged, would rattle at all rpms?

br99

sounds like you are having the same prob as me, my car is at the shop right now, bc i could not figure out where mine was comeing from either.

al02gt

Yup,

I have been working on it for a week trying to figure out exactly what it is. The loudest noise I can hear with my mechanics stethascope is the #4 valve cover bolts. Then I can clearly hear a metal to metal ticking.

I'm going to do a leakdown test and see what that tells me. But I'm guessing its in the bottom end at this point. Unless one of the lash adjusters makes a lot of noise at idle.

br99

I just got my car back the other day and they told me it was somthing in the hydrolics they think maybe a sticky lifter bc it goes away after a short time, they told me not to even worry about it. And this was from a custom shop that only builds drag mustangs. and has been here in florida for a very long time so i trust them.

al02gt

I have gotten seveal different opinions about this car. I took it to a known shop and the guy said it was a lash adjuster. So I replaced all 8 on the passenger side and the noise is still there. Seems to get louder after it gets hot.

My other mechanic says its a wrist pin..? Looks like I'm going to just rebuild it at this point.

al02gt

Well.. I finally pulled the heads off the car. After sending it to 4 shops, everybody wanted to replace the engine rather than to try and fix the problem.

The car had been ticking for about a month. It was much louder when you took the passenger side oil cap off.

Then it blew out the #4 spark plug and I had ford do the TImsert install. (still ticked when I got it back). When I picked it up they said it needed timing chains to be replaced because they could hear it slapping.

I took the cover off and the passenger side top plastic guide had broken around the top mounting bolt and was causing the chain to slap around a little bit. I did notice some wear on the timing gear that slides on the front of the crank timing chain gear.

Anyway, I replaced the timing chains and retarded the passenger bank when I put it back together. I noticed it being flat after 3k.

So I pulled it apart again and corrected the timing. The car was still ticking.

When you start it up cold is takes about 45 seconds for the ticking to start. I think you can hear it from the sound clip in this thread.

After you rev the engine the ticking stops. When the revs come back down, the ticking starts about 5 seconds later. 3 mechanics said wrist pin or cracked piston, the other said bad hydraliuc slack adjusters.

So I have a local shop replace all the lifters on the passenger side and it still ticked when we got it back.

If you unplug the #4 injector, the noise is the same. If you unplug the coil on #4 it would quite down but not go away completely.

ANYWAY-- I took the heads off today and inspected the passenger side. Here is what I found.

Pistons- No markings or scarring at all.
Cylinder walls. - No markings or scarring. Could not get my fingernail to catch any groves at the top of the cylinder.
Valves- All valves look like new with no scars or dents. Only the $4 intake is a little blacker and the others are more brown.
Rollers- all had even wear with no groves or burn marks. Just slightly cleaner looking where the cam contacts it. There were no dents or scars where the rockers meet the valve stem. Just a shiny contact patch.

Lifter bores- All are smooth with no grooves or wear showing.

Combustion chambers all look good with only minor carbon buildup. It does seem #4 has more carbon buildup than the other 3.

I did see some very small aluminium shavings in around the #4 side but just scattered around. I was thinking this was when Ford did the TImsert install on #4 and blew the filings in the engine somehow.

So from what I can tell, all valves, pistons, rockers, etc. are wearing evenly with no signs of any damage. THis is the first SOHC ford engine I have taken apart, but I'm really looking close to find a problem.

Here is what I'm thinking.

Could this be an oiling problem with the #4 lifters? The #4 cam bearing looks good so it hasn't ran dry or been burned. But maybe the galley going to the rear lifters are stopped up??? Not sure if they connect to the cam journal oilers.

If this was a wrist pin, broken skirt, or other piston issue wouldn't their be scarring on the #4 cylinder wall or piston??

I don't think any valves are bent because I flipped the heads upside down with the plugs in, then filled the combustion chambers with oil and had no leakage past the valves.

Maybe the rockers have some wear?


I'm just glad my first timing chain job didn't bend up the valves.


Before I took the car apart this time it ran fine, pulled up to redline and didn't have any misses other than the ticking at idle. It was loud enough to hear inside the car.


I will post some pictures tomorrow to show you the condition of everything.

Any ideas? I'm hoping it's an oiling problem. Or maybe onve of the #4 valves has slightly recessed due to seat wear but I don't notice anything my looking. Like I said, everything seems to be wearing very evenly.