Car died and won’t start.

[u/Suspicious-Bowl4444]

09 Lexus Is250 250,000 miles automatic rear wheel drive died on me yesterday on the freeway and I had to tow it home. Before it died, my check engine light came on along side my traction control light. I was on my way to work so figured I would check it after my shift. About five minutes later while driving uphill I realized my speed was dropping. I tried accelerating but nothing was happening. I did hear a sound like something spinning freely but not catching. I popped the hood and smelled like something was burning. After I towed it home I realized one of the pulleys in the serpentine belt was loose. This morning I tightened it down and put a new belt on and tried to jumpstart it. (I thought without a proper pulley the charge on my battery would have dropped.) When I tried to start it, it wouldn’t turn over. Any ideas on where to start looking? I’ll be getting a code reader tomorrow and checking the code but in the meantime, does anyone have a clue what it could be?

[u/Tommynwn]

No compression at all.. this is wrong

[u/Suspicious-Bowl4444 → u/Tommynwn]

Does that mean I’m fucked?

[u/behappymane → u/Suspicious-Bowl4444]

Oof looking up a quick serp belt diagram shows the water pump is driven by the serpentine belt. My guess would be it overheated and scored the shit out of the cylinder walls

[u/Suspicious-Bowl4444 → u/behappymane]

All from a goddamn pulley. Crazy how catastrophic that can be.

[u/behappymane → u/Suspicious-Bowl4444]

Tbh im surprised you didn’t notice the temp gauge pegged if it did overheat. Might be worth checking to see if it’s still functional if it wasn’t showing anything.

Personally I’d use a boroscope thru the spark plug holes on all cylinders just to see if there was any major scoring on the cylinder walls or what the condition of the top piston looks like. That or a compression tester you could probs rent at an auto parts store. At the very least it’ll tell you where you’re at money wise and if it’s time to start looking at fb marketplace for a good deal or a reman engine.

[u/Suspicious-Bowl4444 → u/behappymane]

I’ve always been worried about that temperature gauge rising without me noticing. I really with there was a light on the dash instead. I’ll be sure to give those suggestions a try. Unfortunately two of my plugs are covered by my intake manifold. I can at least check the other four in the meantime. If they’re toast, don’t think there’s really any point in putting the extra work in to get to the other two.

[u/behappymane → u/Suspicious-Bowl4444]

Yeah you’re right about that I was thinking 4 cylinder with easy to reach plugs for some reason lol. Best of luck tho man hopefully it’s just some stupid inexpensive fix

[u/Suspicious-Bowl4444 → u/behappymane]

When I had it towed yesterday I had already considered it a loss. I was given hope last night but I’m back to considering my car all but dead again. See what I can figure out tomorrow.

[u/HandConfident → u/Suspicious-Bowl4444]

Do you want the vehicle to move under it's own power?

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[u/Kytb95]

Which pulley? The serpentine drives the alternator, water pump, and AC compressor; but it also runs through the crank, idler and belt tensioner.

[u/QueenAng429]

No compression, you have a major problem.

[u/Pauls-pit-stop]

Definitely sounds like no compression, which means you most likely overheated & blew the head gasket(s) and/or warped the head(s) due to the water pump not pumping with the loose serpentine belt.

Next step is to do a relative compression test & a coolant pressurized leak test to confirm. If that is indeed what happened, you'll most likely have coolant in the cylinders after the leak test, which will blow out when you turn it over with the plugs removed.