ALowe336

I was driving on the interstate last night, took and exit, down shifted to 4th, and first grinding, screaching, then some crunching and banging, and as I released the clutch and gave it a little bit of gas the noises got worse, but it seemed like engine was spinning but the tranny did not engage. I've had what sounds like a CV axle popping for about 2 weeks but haven't had the time to replace it, and I assumed the CV axle finally snapped, so I coasted to a stop on some solid ground where I could change it. At a dead stop, I let it keep idling, and realized it was still making the grinding and screaching, so I'm scratching out the CV axle as the culprit. NOTE: the engine did not actually stop or cut off, but I turned the car off after about 5 or 10 seconds of the loud noises to prevent further damage.

I shut the car off, and while waiting for a tow truck, I tried to crank it again while I had a friend on the phone who's worked on cars for the past 30 years. I gave it a quick try to see if the engine turned, and if it sounded like there was enough resistance to figure out if it is getting any compression--the engine did not free spin, so I assume that there is compression--but there was a noise that reminded me of a bicycle wheel spinning with the chain fallen off and smacking the gear, so I didn't keep trying until it started. I left it alone until I got it towed home.

It's home now, and when I first tried to start it, it was like the battery was dead, so I hook it up to my mom's car, and leave the cables on for about 30 minutes and try again, I hear what sounds like the starter trying to turn, but it sounds like either the starter is jammed up, or the engine is locked up.

I popped the hood and looked around, and there are metal shavings, and even a couple chunks, all around the pulleys, mainly the idler, tensioner and alternator. I have a check engine light on that has been on for months for the catalytic converter operating below threshold, my scan tool is at home, and I'm stuck at my mom's right now and can't scan it until I can ride home and pick up my stuff.

I am horrible at diagnostics, but I've replace most components and have even rebuilt an engine on my old MR Spyder. I'm just looking for some advice on a good starting point on diagnosing this thing because I'm freaking out because I'm thinking I having the engine and tranny lock up at the same time and I'm fear the worst. The previous owner said the car was due for a new timing belt (115K miles on original), but Autozone says the Si's, only use a timing chain which will last a lot longer than 100K miles... Please help if you have any insight on what I can do to start trying to diagnose this thing until my mom gets home and I can go grab my scanner (and if it doesn't have a code, what I can do to diagnose what's wrong)

ezone

Year, model, engine, trans?
Location? (A Canadian SI is very different from a US SI.)


Look at the small idler pulley for the serpentine belt, up on top. It may have trashed its bearing.

Otherwise, remove the belt and see if it will crank up and run. (*do not let it run more than a few seconds like this!)
If it runs ok and is quiet without the belt, that indicates you have something in the belt driven accessories that is the problem, like the AC clutch pulley bearing bad. Spin each of those pulleys to find the one that is not quiet and free spinning.

emich

Ezone always on the spot.
Can you explain please why not to let it run more than a few seconds like this?
Thanks

ezone

Because the water pump is driven by the serpentine belt on the 2.0 SI (K series) engine.
It can boil the coolant in the cylinder head area really quick if it's run without the water pump spinning (zero circulation causes localized overheating).

Besides, it sounded like it would be really obvious once OP found the problem, so I figured it should only require a few seconds to figure out if the problem is gone while the belt is removed.

ALowe336

Latest update: No new codes, just the same p0420 or p0402 cat code... With this, and all the other issues going on in my life right now, I haven't felt like working out in the cold to get the belt off, but I'm about to eat, drink some warm coffee and bundle up for it... Also, the screaching, crunching, grinding, was louder than any noise I've ever heard a car make except for at a NASCAR race... it was like someone throwing a chain into a high-speed, high-torque meat grinder that just chewed the chain into a powder... I'm just afraid of getting under it and seeing a rod sticking through the block or something (no oil has leaked so I guess I shouldn't be worrying about anything that extreme).

emich

Got it. Thanks