So I picked up a 2004 MCS last year. About a month ago it started rattling. I had it diagnosed by a local dealer who quoted me $4500 - $7500 for a supercharger. I end up finding a rebuild supercharger with a good warranty and am doing the work myself. I got the new charger on today... Still rattling. When I run the motor without the serpentine belt, no rattle. And of course now the exhaust manifold is glowing red...

I'm tired of ripping this car apart and putting it back together.

And thoughts on what I should work on next?

 

When I had a cracked intercooler boot, my manifold got cherry red from just idling, due to running lean. A clogged cat can do this as well.

As for the rattling, I'd suggest buying a cheap mechanic stethoscope and poke the engine around (on non-spinning parts of course) with it to locate the source of the noise. You'd be very unlucky if you got a shitty rebuilt s/c that does the same exact noise. Is the noise always on? Cold start only? The timing chain tensionner is something that can make a rattling noise when it's getting loose and allow the timing chain to flop around. The crank pulley is not wobbling around?

 

Thanks Ghost.

The timing chain tensioner was replaced with a OEM part. There's no rattle when the motor is run without the serpentine belt. Prior to ordering the supercharger, I looked at the crank pulley. I didn't see any wobbling when running or cracks in the rubber. With rattle still present after the new supercharger install and serpentine belt off, I noticed a slight wiggle in the crank pulle, using my hand. I'm just not sure if that play is normal.

 

If it just happens with the belt, there are only five choices beside the supercharger.

AC compressor
Alternator
Idler pulley
Belt tensioner
Damper/crank pulley.

The idler pulley and belt tensioner aren't that expensive and are known to go bad. Might just switch them out if you haven't already.

You can turn the AC on and off to see if the sound gets worse. Just remember it will add some load to the other pulleys, too.

Same for the alternator. Turn all the lights on...

 

The crank pulley should not wiggle! Look at that again - is the outside moving and not the center? If so, it's pointing to a bad damper.

If the whole crank is wiggling by hand, then it could be serious main engine bearings, thrust bearing, etc. start trying to rule out the simple stuff first.,.

 

It turns out the alternator was the problem. A friend stopped by and used a ratchet extension as a scope. I swapped the alternator out this morning, the rattle is gone.

The exhaust manifold is still glowing, although not as much. I found the line from the supercharger to the pcv was not install as it should have been on the supercharger end. All other lines seem OK.


Question, does the car need to run and adjust the fuel air ratio to get rid of the glowing manifold

 

Hope you kept your original S/C. With the intake air problem, surprised you didn't throw a code. Check for any other intake air leaks by spraying a little starting ether around suspected areas. If the idle picks up, you've got a leak.

 

If it was running for awhile with the vacuum leak it may have weird adaptations. Fastest thing is to reset them. The red hot manifold isn't good....

 

I unbolted the snorkel on the output side of the intercooler that bolts to the intake manifold to make it easier to connect a hose during the install. It seems like that is where the leak is. I'll replace the gasket tomorrow and report back. She did throw a code, P0507. I cleared it and it came back.

Thanks for all the input people, it's much appreciated.

 

Photo of the snorkel I removed

 

I swapped out the gasket but had the same problem. I ripped everything apart and put it back together this morning. I paid close attention to the vac lines and cleaned up the intercooler gaskets. End result, no glow. I'm not sure what / where the problem was and at this point nor do I care lol