Q: Chevy G20 1990 Van not starting. Transmission issues addressed. thumping noise during idle. Reservoir overflowed, no oil pressure

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Recently inherited a van. 1990 Chevy G20 Van. It had issues from sitting, specifically a transmission blockage. After removing the blockage, a thumping noise was extremely audible. Husband assumed it had to do with a cracked head gasket and attempted to use a liquid fix. Letting it idle as the bottle instructed, he began rev-ing it. It began reading no oil pressure and attempted to shut off. He rev-ed it during the attempted shut off and there was a loud thud. The vehicle shut down, and the reservoir tank overflowed. A bit of steam pour from under the hood, not a ton but a bit. he removed the keys and attempted to restart. The light, air, and console lights came on, but the engine will not turn over. Have attempted to start it twice since, with the same results.

My car has 218000 miles.
My car has an automatic transmission.

Hi there. Unfortunately, it’s possible that your husband was correct about the cracked head gasket, but using a liquid "stop leak" product most likely made it worse. What likely occurred is whatever substance that was used to resolve the head gasket leak leaked into the oil galleys, solidified and probably blocked the restriction of oil. This would have caused the oil pressure to decrease and possibly created a worse overheating problem. It’s possible and highly likely that the engine seized up. The only way to determine this is to have a professional mobile mechanic come to your location and complete a car is hard to start inspection.

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