daffy Posted October 6, 2004 Share Posted October 6, 2004 Hi everyone, I bought a 91 LS400 5 1/2 years ago at 187,000 kilometers and now have 385,000 kilometers on it now. My problem is most noticeable at 70 to 80 kilometers per hour, the car jerks like it's missing when coasting. It idles good and accelerates good and seems to have lots of power. I took it to a Lexus dealer and they did a compression test and claim #1 cyl. is 170 psi and all the others are 200 to 220. They think it is the heads. After reading this forum, it seems no one has valve problems. I have always used Esso premium fuel. (Maybe the previous owner used midgrade, who knows?) Has anybody taken the heads out of a Lexus LS400 and had them reground? Is it still worth it for me to do this? How much longer will the bottom end last? (I also use Amsoil oil from the time I got the car.) It looks like I may be attempting to do this job myself as Lexus wants $5.000 Cnd to do both heads. Advice anyone? Thanks PS, I just love this car! Quote Link to comment Share on other sites More sharing options...
SRK Posted October 6, 2004 Share Posted October 6, 2004 The typical variation allowance is 10%. You are still close to that. The low cylinder may be a valve problem, and if it is, it will get worse very quickly. Drive the car and see. If it idles well, and has smooth power, I doubt very much that it needs a valve grind. Put some fuel injection cleaner, like Techron, through it and drive some more. Don't be in a hurry to take it apart. And yes, pulling the heads is a big job. Even the cam drive system, which is a zero backlash gear drive, is different, and more complicated, than most engines. Quote Link to comment Share on other sites More sharing options...
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