Rob94
New Member
Yup!! Got home from work this morning, and heard it clear as a bell. Upon further inspection, am 90% certain it is a timing belt issue. Wish me luck.
The dreaded "rapping"
- Thread starter Rob94
- Start date
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sdpatt
Sr. SHO Engr.
Rob,
Try the belt tensioning procedure that can be done without any disassembly. Remove the small, rectangular "door" in the center timing belt cover and loosen the tensioner bolt about 1/2 turn. Now use a 19mm socket and wrench on the cranks damper bolt to rotate the crank at least 1 turn in the clockwise direction until the yellow, or first, mark aligns with the "0" degree mark onthe lower timing belt cover. This positions the engine at 60 degrees BTDC. Now just torque the tensioner nut and snap the door back on. Unless you are ready to change the belt, this should give you a little reprieve.
Try the belt tensioning procedure that can be done without any disassembly. Remove the small, rectangular "door" in the center timing belt cover and loosen the tensioner bolt about 1/2 turn. Now use a 19mm socket and wrench on the cranks damper bolt to rotate the crank at least 1 turn in the clockwise direction until the yellow, or first, mark aligns with the "0" degree mark onthe lower timing belt cover. This positions the engine at 60 degrees BTDC. Now just torque the tensioner nut and snap the door back on. Unless you are ready to change the belt, this should give you a little reprieve.
SHOfun 93
SHO Member
Well the best way to cure bad rapping is to slug the white guy trying to do it..... 
JaySHOguy
Active Member
You've gotta be kidding me! That's OEM equipment,isn't it
Good luck Rob.
SilverSHO
SHO Member
bahahahaJeremy Hohn:
Well the best way to cure bad rapping is to slug the white guy trying to do it.....
Rob94
New Member
Jason, no, the timing belt is not original. Jeremy, hahahahaha. And Scott, thanks for the recoomendation. I'm heading over to Fred's tonight, and we're gonna replace the belt, pump, and cps while we're in there. Right now, I THINK it is the belt smacking against the timing belt cover, but I won't be sure until we tear it apart. This timing belt only has about 70,000 miles on it, so I'm keeping my fingers crossed. But, it sure as **** doesn't sound like a bearing.
Rob94
New Member
Well, it was a late night at Fred's last night. We took apart the entire front of the engine, replaced the water pump, timing belt, crank seal, cps, and accesory belts. Also did the thermostat and sending unit. A LOT of rust/rot in the fender wells. Special thank you to Bryan King...nice to meet ya man, always nice to have friends in law enforcement. Around 11:30 or so, we fired her back up. Rapping is gone. The timing belt only had 70k on it, but it would appear that it had stretched enough that at idle, it was slapping up against the timing cover. It had JUST started making noticeable noise yesterday morning, so we got it right away. The timing covers were not in very good condition. Lower cover is split nearly in half, the rectangular window is missing. But all in all, things went smoothly, and we got her done in one night. Thanks a lot Fred.....I owe ya buddy.
Congrats on the fix. I had the same issue on mine, I had readjusted the tension and the rapping is gone. Like Scott mentioned before, I'm sure if we readjusted the belt every 10,000 miles, they could last 100,000 like the autos do.
Jason
sdpatt
Sr. SHO Engr.
I'm glad you resolved the original problem. I believe that re-tensioning the MTX's belt every 10,000 miles or so would allow it to "last" as long as the ATX's timing belt, but the question that remains is, do we want it to last 100,000 miles?
Since the belt had stretched enough to let it strike the cover, there was obviously a loss of camshaft timing accuracy and the resulting power output of the engine. Yes, we can re-tension it and keep it in use. But how much do we spend on modifications to add 5 or 10 horsepower when a $32.81 timing belt can probably recoup at least that much.
I will retension the belt periodically, but I will still replace it no less often than every 60,000 miles. Those periodic engine services are also a great opportunity to inspect and correct other wear related conditions.
Rob, I recommend that you cover that rectangular port over the tensioner pulley with a junkyard-sourced "door" or some duct tape. That hole would be a great way to expose the tensioner pulley and timing belt to a great deal more abrasive grit than they were designed to operate with.
Scott
Since the belt had stretched enough to let it strike the cover, there was obviously a loss of camshaft timing accuracy and the resulting power output of the engine. Yes, we can re-tension it and keep it in use. But how much do we spend on modifications to add 5 or 10 horsepower when a $32.81 timing belt can probably recoup at least that much.
I will retension the belt periodically, but I will still replace it no less often than every 60,000 miles. Those periodic engine services are also a great opportunity to inspect and correct other wear related conditions.
Rob, I recommend that you cover that rectangular port over the tensioner pulley with a junkyard-sourced "door" or some duct tape. That hole would be a great way to expose the tensioner pulley and timing belt to a great deal more abrasive grit than they were designed to operate with.
Scott
Humm Rob or scott could you give a little more explanation on the rapping sound. i just started to hear a small knocking type noise this morning.... and i know my belt is ready to replace...
I like your answer, but don't you think that readjust the belt every 10,000 or so will actually slow the stretching of the belt. I believe that it stretches more when a belt is loose due to the flapping. This puts more strain and wear on the belt itself. Now I had this "rapping" (SHOMAN594: it sounds like if you were to knock on your timing belt cover like you knock on the door.) I removed my timing cover to visually see if it was touching the cover anywhere and it wasn't. I retentioned it with Ford's procedure and now the knocking is gone. So in a sense I believe that the actual knocking sound that comes from that area is actually the teeth of the belt placing itself into the gear and this is caused by the loose belt. Many people here cannot do the work themselves and and or can't afford it. This could be a more cost effective way to maintaince the SHO. The belt is cheap but not the labor. This is my honest opinion. thumbs_u
Jason
<small>[ April 25, 2002, 10:50 PM: Message edited by: Shoman94 ]</small>
But the knocking noise will go through the whole engine right ??? Dan's sho had the same problem it was severe and was really loud (timing belt) mine is a little softer but it goes throgh the whole engine just like dans did. ie. if you put your ear on the intake you could hear the sound.
Rob94
New Member
Scott, thanks for the heads-up on the "door". I've got some family friends in the "auto recycling" business.....I'm gonna contact them and do a search for used and good condition lower covers. The old belt appeared in good condition, but while in there, we just replaced it, as well as all the other usual 60k items.
greensho
New Member
I think I have exactly the same problem (knocking sound) in my '93 ATX. The sound is pretty loud and kind of embarresing to drive the car around.
I was told by a local mechanic that the sound is coming from the timing chain tensioner and now waiting for the two parts (left and right) from Ford Parts Network.
My car was due for a 100K anyway so I'm getting these replaced along with the others.
I was told by a local mechanic that the sound is coming from the timing chain tensioner and now waiting for the two parts (left and right) from Ford Parts Network.
My car was due for a 100K anyway so I'm getting these replaced along with the others.
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