98gtstinks

<FONT face="Arial, Helvetica, sans-serif" size=3>I own a 98gt and am trying to figure out where a tapping noise is coming from. It sounds mostly like it is on the right side valve train, but it at times sounds as though it is from the front of the engine. I have replaced all of the vavle tappets on the right side and checked the rocker arms. I have also stripped the front of the motor down to nothing and the sound is still there (thought it may be a water pump, power steering etc). I found a web site that said a 1:1 ratio between a timing light and the noise would indicate a timing issue and a 1:2 ratio would indicate a crank related issue. The noise seems to be a 1:1 ratio, so it is still pointing to a possible timing issue. The noise also starts at 1500 rpm and is more noticeable under any sort of load. Everything about the car is the same as before the noise started so upgarde/mods are not an issue. If anybody out there has a word of wisdom please let me know. At this point am thinking maybe timing guide or tensioner, but I'm new to the 4.6 and would like some help. Sorry this post is so long, just wanted to be as informative as possible.</FONT></P>


<FONT face=Arial size=3>Thanks</FONT></P>

mdvaldosta

if its under a load then either exhaust leak or detonation comes to mind. a good idea may be to get a mechanics stethascope (however you spell it) to find where the noise is coming from</P>

awwimer

ya thats what i would say or a long extension and put it to your ear sorta works like a mechanic stethascope. listen to your injectors see if that sounds like it also. stupid but check all the cheap things first. what kind of oil you use how many miles are on it? just go through the basics like any other motor.

98gtstinks

I just finished working onmy car and thought I would share my adventure. Around the middle of December my intake manifold broke at the thermostat housing and in the process of replacing it something managed to drop in the #8 intake port. I decided to do a valve job, and in the process checked the bottom end of the car. The tappig noise was caused by the connecting rod bearing on #1,it was just about completely gone (#5was just as bad). All the other conrod bearings where ok, the mains where ok and the crank was ok.</P>


After getting everything put back together and testing the car, the noise is gone, the intake does not leak and all is well. Maybe this car will hold together for another 78000 miles.</P>

Dan04COBRA

As long as there is no damage.. <IMG src=smileys/smiley2.gif border="0">

BLKSTANG9879

DID it start, When you were at a high RPM.Cause it sounds like one of your rockers might have came off. The modular motors are great for that. Someone needs to make a aftermarket set soon.

97GT210

im havin the ticking problem too. im droppin the oil pan this weekend and takin a look at the rods and crank

yellow4.6

My z28 did that if I used 87 octane. One thing to try is 91 or 93 and see what happens. If it goes away maybe it ws detonation?

97GT210

ive been hearin from alot of people that like 97 and 98 4.6's were crap.. cause they were the first year.. also i have heard that the bearing can wear out if the car has been dogged at low rpm's or something like that. ill find out what my problem is when i drop the pan sunday.