intermitent knock/tap from motor on passsenger side

[jaidedeye]

installed VT stage 1 cams in a friends 01 GT. before the cam install the car would blow a little blue smoke on startup. after asking him,the owner said it was ok to go ahead with the cam install. the cam install went smoothly. everything timed up perfectly and the car cranked up and ran perfectly. well, once the car warmed up it does not want to hold idle when coming to a stop, blows smoke and has a wierd tap/knock noise coming from the lower passenger side of the motor near where the oil pan and block meet. its obvious at idle and while driving near buildings and walls. but as the rpms climb over 2500-3000 rpm's the noise gets quieter. the owner of the mustangs good friend said he has heard the car making that tapping/knocking sound for the past 3 weeks...(wish i would have known before the cam install)

the sound is hard to describe but to me and all my car buddies beleive its a minor rod knock. its like "CLACK-CLACK--------CLACK--------CLACK------CLACK-CLACK"

it speeds up with rpms but like i said its almost like it gets quieter will more RPM. while reving he motor the noise get worse on the initial rev up. the noise is best heard under the car and in the passenger wheel well. there is no knocking or tapping coming from the valve covers/heads or any component on the top of the motor.


the car is a 2001 GT, long tubes, O/R H pipe,cat back, CAI and VT stage 1 cams. on the road the car runs and pulls great isnt down on HP by any means

so, to recap:

wont hold idle below 1000 rpm
smokes (bluish smoke)
knock/tap sound near oil pan on passenger side


sorry if this thread is hard to understand..im really tired

 

[mixedbreed02gt]

sounds like some main bearings going bad.

 

[jaidedeye]

sounds like some main bearings going bad.

really? ive never had problems in my stangs with main bearings making noise so im not familiar with the type of noise it makes.

 

[mixedbreed02gt]

really? ive never had problems in my stangs with main bearings making noise so im not familiar with the type of noise it makes.

had that problem on my 91 5.0. I could be wrong, but it also could be the carrier bearing.

 

[trinity_gt]

The idle issue may be due to not have a tune installed for the new cams.

The knock and oil symptoms sound like they may be terminal. If you can isolate the noise to a cylinder or two, pull their plugs and have a look for oil on them. Check the compression on those cylinders and perhaps a leakdown test. I suspect you might find excessive blow-by; perhaps a cracked piston or collapsed skirt is causing oil control issues. For the knock, it probably is a rod. The only way to know for sure is to drop the K-member and pan and inspect the assembly up close.

 

[jaidedeye]

The idle issue may be due to not have a tune installed for the new cams.

The knock and oil symptoms sound like they may be terminal. If you can isolate the noise to a cylinder or two, pull their plugs and have a look for oil on them. Check the compression on those cylinders and perhaps a leakdown test. I suspect you might find excessive blow-by; perhaps a cracked piston or collapsed skirt is causing oil control issues. For the knock, it probably is a rod. The only way to know for sure is to drop the K-member and pan and inspect the assembly up close.

thanks for the advice.