I have a 92 ls400 and it ran hot . The next day I got a puff of smoke from the passenger side of the motor then my rpm dropped really low . The car will run but takes off really really slow . Off for the next 2 days and what and where should check ?? I would like to thank everyone for the great info !! I have been able all the work on my car for the past 2 years !! Could not have done it without you guys !! Thanks again !!

 

You want to check the oil to make sure no coolant is in it. Then check the coolant reservoir to make sure no oil is in it. This will help determine if you blew a head gasket. This could occur with an overheating event. If there is oil in either the fluid will be milky.

 

I checked the oil and the coolant tank and everything looked ok. So I ran the car for a while befor I started taking it apart and after a while I got smoke from passenger side of motor then from by rear tire on the same side . I looked under the car and the catalytic converter on the drivers side is glowing . Dont know what do next .

 

ouch you could have a clogged cat, or if not sounds like a blown head gasket. pull your plugs and see if you have antifreeze on them

 

I checked the spark plugs and some had oil on the treads and looked like oil dryed on the plug heaed and a orange color on some that may be coolant . I changed out the spark plugs and it run a little better but still very slow from a stop and the que catalitic cov. is still getting red hot after running awhile .

 

what color is your antifreeze and stop driving the car. im gonna say your cat is clogged and created serious back pressure and blew your oil gasket out and hopefully not your head gasket. dont do any more damage until you check out that cat. is the reservoir bubbling up or do you see bubbles in your radiator with the cap off.

 

what in the name of god are you talking about Oil gaskets??

OP- you have an ignition or fuel issue from the sound of things, your cat's getting red-hot because unburnt fuel is pouring into it and burning in the cat. fix your (likely ignition) issue and your cat won't go red-hot anymore. However it may be too late as once they go that hot the internals tend to melt and become useless.

if only one cat is getting that hot i would strong look at the dist. cap/rotors/wires & ignition coil for that bank.

 

You can take off the cats while u work on it. To me sound like it running on half of the engine if only on of the cats turning red. When you took off you spark plugs where 4 black and the other 4 looking good?

 

excuse me mr moderator, i meant to say valve cover gasket, but was typing to fast lol. i built a 11 second car with my bare hands so i do know a little something.

 

Yes i am getting bubbles in the coolant . Thanks i am off for the next few days and will work on it .

 

Ok i took took the cats out and the car ran really loud but ran a little better but a little slow from stop . Is this to be exspected ?