vroom8 Posted June 9, 2008 Share Posted June 9, 2008 hello everyone what a great forum! I just bought a 1992 400 LS, and guess what? I think my head gasket is cracked or something...according to the mechanic I had take a look at it...water in the oil! It starts up great, but after a couple minutes, the compression drops and it has no power, or very little. I have had someone tell me that the HG is blown, but also the Cat Converter is plugged.. If I put a new Cat in it can I still drive it?..for a while how about putting a hole in the converter..to see what happens? Quote Link to comment Share on other sites More sharing options...
chilkoot Posted June 10, 2008 Share Posted June 10, 2008 head gasket failures are very rare on LS's. If you just bought it, more likely that the oil has not been changed in years and has broken down. change the oil and see what happens. the cats should have nothing to do with that. if they are bad you will smell fuel and they will glow red as the engine bogs. Quote Link to comment Share on other sites More sharing options...
wwest Posted June 10, 2008 Share Posted June 10, 2008 head gasket failures are very rare on LS's. If you just bought it, more likely that the oil has not been changed in years and has broken down.change the oil and see what happens. the cats should have nothing to do with that. No, it is not altogether unheard of and might even be a fairly common failure mode for the honeycomb structure holding the catalyst material to begin to break up and then clog the exhaust. The symptoms even indicate this might be the case, engine degrades as exhaust pressure builds the longer the engine is run. if they are bad you will smell fuel and they will glow red as the engine bogs. I agree with the "glow red" (sometimes only obvious at night) part but why the fuel smell......??? Quote Link to comment Share on other sites More sharing options...
python Posted June 10, 2008 Share Posted June 10, 2008 have ur mechanic do a block check Quote Link to comment Share on other sites More sharing options...
vroom8 Posted June 11, 2008 Author Share Posted June 11, 2008 thank you chilkoot, wwest, python...!! I have just had another mechanic take a look and he says there is no water in the oil...also the oil is not frothy or discolored, so he thinks the HG is not the problem. Thank you for the tips on Cat converters...there is indeed a strong smell of exhaust or something as I start the engine sometimes...I believe there are oxygens sensors in the converters, and am wondering if this is not the problem??, but I will certainly check out the glow..if possible. The car starts right up...drives for about a block and then loses power and I can hardly get home. I have also noticed the temperature is not heating up....my gauge is barely moving past 1/4....even when I let it idle for a while. Any ideas would be very welcome, as the mechanics here don't seem to know much about lexus. Yea, I just bought it and it was fine for about 2 months, but then this started. Quote Link to comment Share on other sites More sharing options...
VBdenny Posted June 11, 2008 Share Posted June 11, 2008 I noticed that mine has a smell like that when the cars sits around for awhile and is driven only a little. I changed the oil and went out and burned up a couple hundred dollars of premium at about 80mph on America's Interstates in the last few weeks and wow, no smell anymore. I guess these 400's like to run and the more you drive them, the better they run. My Rx. Adminster one tank of 93 and go burn it up. PS Be careful you don't get caught. Quote Link to comment Share on other sites More sharing options...
vroom8 Posted June 11, 2008 Author Share Posted June 11, 2008 I noticed that mine has a smell like that when the cars sits around for awhile and is driven only a little. I changed the oil and went out and burned up a couple hundred dollars of premium at about 80mph on America's Interstates in the last few weeks and wow, no smell anymore. I guess these 400's like to run and the more you drive them, the better they run.My Rx. Adminster one tank of 93 and go burn it up. PS Be careful you don't get caught. HA-HA!!- LIKE YOUR SOLUTION!! Perhaps it just needs a good run....certainly going to change the oil..my dad used to say that cars need to 'burn the carbon out"...nice excuse to let it rip... Quote Link to comment Share on other sites More sharing options...
wwest Posted June 11, 2008 Share Posted June 11, 2008 All-in-all it might be a bit cheaper, less expensive, to simply pay $100 for enough time on a dyno to "blow the carbon out". Or quickly, from a full stop, accelerate up a steep hill about twenty times in a row... But who am I to "talk", ~5 hours at legal speeds puts me in MT....... Quote Link to comment Share on other sites More sharing options...
vroom8 Posted June 11, 2008 Author Share Posted June 11, 2008 All-in-all it might be a bit cheaper, less expensive, to simply pay $100 for enough time on a dyno to "blow the carbon out". Or quickly, from a full stop, accelerate up a steep hill about twenty times in a row... But who am I to "talk", ~5 hours at legal speeds puts me in MT....... I might just do a shamanic dance, and hope it takes care of itself.... I am still thinking it is a sensor...somewhere...might have to hook up to a puter ;) Quote Link to comment Share on other sites More sharing options...
eatingupblacktop Posted June 12, 2008 Share Posted June 12, 2008 Or quickly, from a full stop, accelerate up a steep hill about twenty times in a row... Yes, WOT 0-70 or so, minimum 10 times should clean out the cats. Just don't park over any dry grass afterwards! B) Quote Link to comment Share on other sites More sharing options...
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