Noise Diagnosis

[benoitthegr8]

The mods are in the signature, basically ran the car hard on Saturday. My buddy has a Mitsu Galant VR4, has FMIC, Turbo, ect. He thinks his car is fater than mine, so I agree to a race for a wager. After I smoke his a$$, I take the car home and shut her down for the day. Yesterday, I start the car and immediately I hear a ticking noise. I climb all over the car trying to figure out where it is coming from, I could audibly hear it the loudest from the passenger side head under the car towards the back of the block/near the convertor cover. I put the car up on jacks and crawled around under it trying to pin point the sound, really couldn't tell where it was coming from besides as decribed above. Have not drained the oil yet, or tore into the oil filter. I have a funny feeling I spun a rod bearing. But, no knock, I'm only running the car at 14 lbs of boost on 93 octane. The 02's are a little low at WOT 730-750, but all the other numbers on the scanmaster look good. I'm still trying to get the 02's up before I crank the boost up. I recently replaced the plug wires, but I don't see how that could make a difference. The car still makes good power, not that I've been into it since I've heard the noise, but it doesn't feel like I hurt it. What are the telltale signs of a spun bearing??? how do I confirm a spun bearing? suggestions needed... thanks....

 

[cool 84]

Probably a header leak. It wasn't ticking when you shut it off but it ticks when you first start it cold? If you have a spun bearing, there will be no doubt. Usually you have a knock along with a horrible squeek.

 

[benoitthegr8]

Is a header leak going to sound like a metallic tap???

 

[cool 84]

Is a header leak going to sound like a metallic tap???

A single cylinder leak can sound awefully similar.

 

[benoitthegr8]

Also is there a test you can do to make sure your knock sensor is working properly????

 

[BlackBandit]

If it's an exhaust leak it will get louder when you hit the gas (at least until you build boost) and then go away if you let off and coast.

 

[notacarlo]

vac hose to the ear....search all around the suspected area. I agree it sounds almost exactly like a lifter tap.

 

[No Tie]

My 4.1 had p/s header leak rear cyl. last week.Sounds just like your discription. Easy change if that is it.

 

[affordablegn]

Noise

It could be a header leak.
It could also be a cracked flexplate.
Or even some loose flexplate bolts.
I have had all of the above cause the noise.
Let's hope it's not serious.
Good luck!
Jason
AffordableGN

 

[benoitthegr8]

Checked the convertor bolts, they were tight... I really crawled up in there and dicovered a leak between my test pipe and the DP. I put a high dollar stainless Dynomax Lap-Joint clamp. I guess because of the sweep in the DP it couldn't seal completely. The funny thing is the exhaust leak is blowing in the direction of the engine??? I guess it's time to bolt in the THDP, I still have the stocker in there, I've been waiting until I get my TE44 back from precision to install the DP. thanks for all the replies...