landar

Justin, it is very important to make a distinction between "not starting" and "not cranking". I believe you mean it will not crank(turn over). So, if it is not cranking, it could be several things. Your battery could simply be getting tired (old) and needs to be replaced. Often, when an older battery gets discharged completely (by leaving the lights on), it cannot recover. This is especially true if the engine seems to crank slowly before starting. And, it could also be bad battery post connections. That usually gives the rat-a-tat-tat-tat rapid clicking sound. It could also be the alternator not charging the battery properly but since you do not mention a dash light being on, I would not think that to be the case. Finally, and what I fear may be the case, is that your starter solenoid contacts are going bad. That usually manifests itself as hit-n-miss cranking such as you experienced.

Good to know Dwight. Glad you found the root cause and got her back on the road. Thanks for posting the fix.

The head bolts use what are called "stretch" threads. They stretch on the first torquing and are not to be used again. I am not surprised that your engine is running fine now. But someday in future, during WOT, you might lose a head gasket. So, if you are talking about replacing the crankshaft seal, then yes, the radiator should come out. In fact, your timing belt will need to come off as well. Depending upon when you last changed the belt, I would just go ahead and do a complete timing belt and water pump service while in there.

I was afraid you were going to say that. I would be concerned with removing a single head bolt and trying to get everything back to proper pressure(sealing-wise). Did you buy a new bolt to replace the old one and torque it properly?

It could be the fuel pump but since you just did the timing belt, check all of the connectors that you removed and make sure that they are all properly seated together. If you think it is fuel, spray some starter fluid into the intake snout when trying to start and if it does, you have a fuel issue. If it does not help, then it is most likely electrical.

You removed what bolt?

Charles, these Lexus cars are pretty well build but... the plastic crap around everything can be really, really frustrating to get off. I can empathize with you. What I usually do with a screw that appears to be stripped and will not back out is to apply outward pressure with a tool (screwdriver or small pry bar) behind the plastic while I 'unscrew' the bolt. That usually gets it to pop out.

I was reading on a forum somewhere (I think CL) about how someone put the crank pulley back on but did not properly align the pulley key with the slot in the crankshaft. They just 'mashed" it together and let it go. Well, the engine ran for a while but then started performing poorly. That's when the guy found the problem. The crank pulley was literally slipping on the crankshaft. Almost unbelievable but here it is -> http://www.clublexus.com/forums/ls400/726021-1997-ls400-timing-belt-possibly-skipped-teeth.html There are several pulley holding tools that you can use to get the crank bolt loose. The best way is with a strong impact wrench but if you do not have one or it is too big to fit in there, then you will need the holding tool or you can slip an allen key in the flex plate (that is what I did although it really is an 'unprofessional' way to go ;-)

No, I would not just blindly replace them yet. You have to remove the intake manifold and its a pain. Instead, I would investigate a bit more. First, make sure that the sound you are hearing really is engine knocking. Maybe it is something else that just sounds like it. Or maybe it really is a knock or pinging (pre-detonation sound). So, I know this might sound counter-intuitive, but what if you purposely put lower octane fuel in the tank to see if the symptoms get worse (more/louder knocking)? Or...you could buy an octane booster, add that to the tank and see if the knocking subsides somewhat. Neither would be used for long, just to get an idea if the knocking sound really is related to pre-detonation. Real pre-detonation can be harmful (in the long run) to your engine. It is very hard on the bearings, rods, pistons. How long have you owned the car and how long has it been making this sound?

Maybe a knock sensor is going bad? Have you checked for any engine codes?

Well, that is not a head bolt in the traditional sense but it is some sort of plug and the casting appears to be broken on the top side. Can you verify that the top part of the hole is broken off or not? At least that's what is looks like in the pic. [edit] Guess it is a head bolt. I was looking at it from the wrong perspective as a depression when it is actually raised.

Welcome, Ken and thanks for sharing that info. The #1 cylinder plug looks the best and your mechanic kept pulling that plug never seeing #7, which is probably the worst with carbon build-up. The electrodes do look a bit worn away so you just need to keep an eye on your new plugs and see how they last and perform. You should use anti-sieze on the threads when you replace them. You have 161k miles on the engine so the rings and such may be getting a little leaky. You would have to do a leak-down or compression test to see what the health of each cylinder may be. BTW, what kind of petrol do they have in Australia? Is it high octane with detergents? Is it the so-called Tier one gasoline?

Being a former dentist, you may have to pull that connector tooth! ;-) But seriously, if you have purchased the new sensors, study the latch mechanism carefully and you should be able to figure it out. Usually, it involves pushing down on an outside tab or using a screwdriver to pull/push the latch upward/downward. In any case, you will also need to be applying outward pressure on the connectors so that they come apart when you release the latch.

Brian, it is very difficult for anyone on a forum to pinpoint your particular issue(s). We can try to help but you will have to be extremely patient using the forum to get to the root cause. It is, for me, like trying to troubleshoot your car by looking thru a soda straw. So, to get us up to speed on you issue, are you still trying to figure out the overheating? Since you mentioned the engine running rough, have you checked the coils to make sure they are working?

Yes, +2 on AZHotLs comment. Plus, the CD mentioned in this thread is for a 98-00 model, not your 1990. You can go to the Toyota TIS site and for $15, get a 2 day pass to look at any Toyota or Lexus model and download factory service info to your hearts content.

Welcome, Greg. Just a couple of thoughts... having higher than normal emissions could point to incomplete combustion of the fuel. And usually due to a rich fuel/air mixture. The fact that you changed the cats and got an improvement suggests to me that your mixture is rich and probably was overwhelming the old, worn cats. They might not have been shot but not working like when they were young pups. The cats basically burn up any remaining fuel in order to lower emissions. You can also tell quite a lot by checking your MPGs. On the highway and driving at 65, you should be getting north of 25 MPG. If it is anything less, then the mixture is probably too rich. I do not know if you have been keeping tabs on your MPG. So, what makes an engine run rich? Lots of things could. On the older LS, the coolant sensor can get lazy and report a cold engine when it is really up to temp. This causes the computer to enrich the fuel mixture all of the time. Then again, it could truly be a 'cold' engine, the thermostat not keeping the engine up to peak operating temp. Could also be weak spark because of weak coil(s). I suppose a drastic difference in emissions readings between the two banks(left/right) would point to the offending side. But if they are relatively close, I would declare the coils good. Just some things to think about. I believe that if I were you, I would swap out the coolant sensor as a start. BTW, here is the lexls site for reading codes -> http://www.lexls.com/tutorials/intro/codereading.html

Ahh, that makes sense. You can step in any time! I am more than happy to share the dance. Dance away ;-)

Interesting AZHot. How does this tagging work?

You mean alternator not starter, right? Anyway, as long as the side connector has the same pinout and does not stretch the existing harness and does not put the harness in the way of the belt...I think you will be ok. What brand is that new alternator? How does that power steering pump look?

Replacing the alternator is something you can do yourself. If the part is a Denso, that is not a bad price. You could even have the existing alt. rebuilt for much less. Remember that the power steering leak will need to be fixed too.

I do not see a ground connection in those pics but everything else looks pretty clean. You might pull that connector apart and examine it and clean it while you have access. But otherwise, nothing stands out as being corroded. Back to square one, I guess...staring at the schematics.

Charles, I have never removed the carpet in an LS but found a site that has some generic info on carpet removal. http://www.ehow.com/video_4942137_automotive-carpet-replacement-tools.html Now, you are not replacing the carpet, you just need to get to the O2 sensor wiring connectors. So, I would work from the outside(meaning door side) and lift the carpet from there to see if you can get enough clearance to feed the O2 wiring through the floor pans. You might be able to get the wiring and connectors snapped together without releasing the inner carpeting anchor points. Once you get the outside edge lifted a bit, use a flashlight to view the existing wires/connector and maybe you can feed the old out and new in with a minimum of carpet lifting.

It is not because of brakes, despite the ABS light. The fact that the alternator light is coming on, indicates a low charge which usually points to the alternator. So, you will want to check the charging system. Hopefully, it is as simple as a bad alternator. If the alternator is wet with fluid, you may have power steering fluid leaking onto the alternator and that would be the cause of failure.

I would want to know just where this steam is coming from by pinpointing the escape point. Could be due to lots of things but consider the simple things first. Rather than pulling the heads, why not do a compression (or cylinder leak down) test first to gain some insight. You may very well need a new timing belt and water pump but that is really not a 'rebuild', just scheduled maintenance every 90k miles. So, I would encourage you to take a deep breath and consider how to attack this steaming issue. I probably do not have all of the facts as is often the case but start with simple checks first. These engines are pretty hardy and usually do not require major rebuilding.

Huh?? Let's back up a moment. What problems are you having, specifically, which lead you to believe that you are in need of some major engine work? BTW, you should always try to pick a title which best describes the question(s) you would like addressed. "Landar" is not a good one, unless I am your problem/issue? ;-)