Engine Bearings

[Banshee365]

1996 LS400 with 190k miles. Regular 7,500mi oil changes with mobil 1 filter and mobil 1 10w30. The car doesn't burn a single drop of oil at all. However, if it sits for several days and you start it you hear knocking on the bearings until the oil pressure builds. I'm wandering if the rod bearings are a common thing to go bad on these cars. I'm also wandering if it's something people replace sometimes or just find another engine. I'm thinking about sending off an oil sampe to get analyzed on the next oil change to see if there is abnormal wear. I did some searching but since you can't search any word 3 letters or worse the search function is sometimes useless because you get so many hits. Thanks again.

-Kelly

[SRK]

This is a bit of a long shot, but it's cheap. Install a Toyota-Lexus filter, because the aftermarket one may be draining back over a few days, and has to refill. I have seen this on other engines but not on the Lexus V-8. It's worth a try before you spend more money and time.

[TA in KC]

Your problems seem odd to me. I've never heard of an engine bearing failure on a Lexus LS engine. Is there any particular reason you are running 10W-30 instead of 5W?

[Banshee365]

Your problems seem odd to me. I've never heard of an engine bearing failure on a Lexus LS engine. Is there any particular reason you are running 10W-30 instead of 5W?

Yea, that's what I was thinking about the engine problems, I havn't heard of any. We've had the car for about 110k and the previous owners used 10W30 but I may switch to the 5W30 if that is what's really recommended. I'm going ot try the filter because I had a Ford Lightning that knocked when I changed to an AMSOIL filter then went away when I put the Motorcraft back in it. Thanks guy's, I guess we'll see when I change the oil again.

[Alexander the o.k.]

The ls has a bit of a valve tick on startup from what I've heard. Search 'valve adjust' or some version of that term. I believe it will yield some results altho it may not be needed if you can do a simple fix first.

If you hear tapping as opposed to a 'ticking' AFTER warm up, then I'd look into having them adjusted.

Two suggestions.

Immediately switch to the recommended oil- 5w30.

Yes, I know it's summer, but if average temps are below, I think it's 100f, then go 5w. It is a thinner oil and will lube the top end quicker on startup. If it sounds a bit worse after the 5w, it may very well be a valve adjustment.

Two- start changing the oil at 3K to 4K MAX. Do that for a couple of changes, and see if it helps.

You could even try a synth blend.

These engines are virtually bullet proof if taken care of. No reason not to go to 500k or more with care.

Here is a quick link if you're a DIY'er (for 1uzfe ) :

http://www.lextreme.com/valve_clearance.html

[eatingupblacktop]

What does your oil look/feel like after each drain? Is there oil in the filter and what does it look like? Changing the oil to sw in summer may or may not be helpfull. It does circulate faster but also drains faster leaving less of a film on the cams etc, for your next startup. Full synth is certainly the fastest and stays on the cams longer. However if the engine has become loose with age and mileage, you may find that with synth you'll be burning some. As suggested, oem filters might help. You might also want to check the oil pump. If you're not getting quick pressure after startup, then you're increasing wear.

[Banshee365]

Well I just got home to check on the car. WOW does it make alot of noise at startup, for sure main bearings. I'm mechanically inclined and have kept very good care of this car for my mother. She does mostly highway driving and I change the oil at 7000 intervals with mobil 1 10W30. I'll switch to 5W30 with factory filter and see how that does. The car has sat for 1 week without starting. When I went out and started it up it rattled like it had no bearings at all for about 1 second then went totally quiet. I let it warm up and did gunned it to 5k a few times and it sounded as smooth as a Lexus should. I think has some bad gas because it's idling weird and responding slow. It has very recent plugs, caps, rotors, and wires that I did to it, all Lexus OEM parts. I have never heard it rattle like that on start, it sounds really really bad. As I said, it goes away after about 1 second or so. I'm really worried that the bearings are damaged and it has permanant damage. The car doesn't burn a single drop of oil over 7000mi. The car has about 190k on it. I'm thinking about sending in an oil sample to get analyzed but I know it's going to say there's bearing material because of the last few starts with the bottom end banging. I'm letting the car sit for about an hour then I'm going to go back out and start it. I'm getting ready to put $800 worth of parts in the front end with bushings and upper control arms so I'm really hope I'm not wasting my money on a car with a motor on it's last leg. It has NEVER been ran low on oil and there's no reason that this motor should be developing problems that stem from lack of maintanance. What do you guy's think, no one has rolled in main bearings before? Thanks for all the advice.

-Kelly

[SRK]

Look, the difference between 5W-30 and 10W-30 is meaningless in its effect on this problem. Change it all you want, but it won't make the noise go away.

I advised changing the oil filter. Your latest description makes me think that's the problem.

It isn't mains you're hearing - it's the rod bearings.

If you think you're going to spin in some bearings on an "in-frame" repair, think again. Buy a used engine would be easier.

I've told you what I think twice now.

[Banshee365]

SRK, thanks for your advice (twice) and don't think I'm not taking it with the oil filter recomendation. I am looking for more than opinion, however, and yours is greatly appreciated. I will change the filter to a yota filter. Here's another update. The car sat overnight for 9-10 hours. I woke up this morning to take it to an appointment and this morning it cranked up like alway's without a hint of knocking. This only seems to happen when the car sits for a week or so. There is no knocking while driving the car under any condition. I floored it a couple times to clean it all out with some fresh fuel and it runs like a sewing machine. I would think if there was serious bearing issues it would knock more than just 1 second during startup after it sat for a week. 10 hours should have been plenty of time for oil to drain out of the bearings and cause a audible knock at startup on dry bearings. If I ever did run into bearing issues I'd love to replace the bearings because the rest of the engine is in good shape and it doens't burn oil. I'd hate to buy a used engine that hasn't been taken care of that burns oil. Thanks again for all of the help. Does the motor sound like it's alright? Again, hoping I'm not putting all this money into the front end for nothing.

-Kelly

[python]

uh..ur oil filter has no way of leaking back into the motor due to the positioning of it...if it were upside down then yes or on its side, btw wix filters are the best on the market and they are sold at all Napa auto parts, ask for the gold.....1348 i believe is the number

[landar]

uh..ur oil filter has no way of leaking back into the motor due to the positioning of it...if it were upside down then yes or on its side, btw wix filters are the best on the market and they are sold at all Napa auto parts, ask for the gold.....1348 i believe is the number

I would tend to agree with SRK, change filters and see if there is any noticable difference. If none, go after the oil pump as eatingupblacktop recommends. It may be getting weak.

You could install an oil pressure gauge and record the numbers.

The really good news is that your engine appears to be fine despite the symptoms as you say there is no oil consumption.

[python]

u can agree with him all u want, but the fact is, the filter has nothing to do with it....end of story.....one way to find out....pull it off after it sits over night and see if its full or not