mak89

iTrader: (6)

"This is a true statement. OBD II vehicles are strictly based on Emissions and Safety. If the CPU detects something that is not rational, it will either set a code or stop the car. ECT sensor is one of the priority sensor. The reason why the car stopped was because the ECU is seeing a spike in temperature, in order to save the engine from blowing/overheat bad it automatically shuts off the engine."

got this from https://www.clublexus.com/forums/gs-...t-start-2.html

Is this true with +1998 sc3 models??

pnewman30

I'm going to jump on board here looking for some guidance too. Last night my wife calls me and says her SC300 overheated and she pulled off on the highway. I get to the car and she tells me that steam blew out from under the hood. A LOT of steam. She indicated there was no loss of power at any time/low RPM's, rough idle, etc. But that when she pulled over during full steaming that the car felt like it wanted to die, lol. Gotta love the descriptions! She additionally said that smoke/steam was coming out of the tailpipes while she waited for me to arrive.

I got to the car 30 min later and the temp needle is pinned at H. There was a milky explosion under the hood coming from the radiator cap. I tried to start the car and it would crank, but not pull over.

I tow it home and take a deeper look into it:

1. Radiator is empty
2. Coolant reservoir is full
3. Temp needle is back down to C
4. Dip stick has no oil on it. NONE. ZERO. NADA. - further there is no milky liquid on it.

I filled up the radiator with green 50/50 and coolant began to leak out the bottom under the car (indicating crack somewhere). I tried to again crank it, but it won't turn over. It will crank, but not turn over. I never recall seeing any milky stuff in the dip stick and have the oil changed regularly.

I'm going to put a quart of oil in the car in a few hours and try to start again. Did she blow the head gasket? Would a blown HG stop the car from starting? I've revoked her Lexus privileges permanently by the way.

InLyneTrbo

iTrader: (5)

you have a warped head and/or blown HG. Your car will not start because you have a buildup of coolant/water in multiple cylinders. Same exact thing when my SC overheated. Don't try to start the car too much or you could bend a rod or cause further damage to your block. Start looking for a new head and buy a new HG. Oh yeah, and don't let the car sit with the water in your cylinders for too long because it will rust away the cylinder walls. At that point, you might as well find another used 2jzge.

To ensure this Dx is the case, pull off your Intake mani and check out your spark plugs. 2 of my plugs had been split right down the center of the plug, literally speaking, it was broken in half about half way up the plug. It also had an orangish residue from the rusty water rising up from the engine trying to combust and forcing the water onto the plug, along with the compression which is probably what damaged the 2 plugs.