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Valve Cover Gaskets - Gen 1 Ls400, Who Here Has Personally Changed The


90LS400Lexus

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I read this DIY link: http://www.lexls.com/tutorials/engine/valvecover.html on how to change the gaskets yourself, but WOW it looks like a task.

Now that I have got a couple of other things done on my car, whether or not I sell it, I would like to maybe get these valve cover gaskets replaced, as they have been leaking for awhile now. I had thought about getting a mechanic I know of replace these or even do them myself, but rethought that after part about me doing it myself after I read that info on that link again. ;)

I know mine are leaking, because I do get a faint oil burning smell from under the hood, most of the time when the engine is full warmed, but what concerns me is that it will occasionally put out this big puff of smoke from the left rear side of the engine near the valve cover. One day I had it idling in the driveway and when it did it, I recognized it as the smell I had been occasionally smelling and it appeared from the back driverside of the engine. Its only noticable when it does that if I am setting in a drive-thru, traffic light, or stopping somewhere. Driving, I guess it blows away and not smelled.

I am assuming that oil is dripping down on the manifold when it does this, but its strange because it smells like diesel fuel smoke when it does it, rather than that typical burning oil smell. Its been doing this for awhile now. It must be so minor though because last couple of times I have let the oil go between 4000-5000 miles before changing and the oil ALWAYS stays full on the dipstick. I just dont want to cause a fire, but its been doing this for about 16 months now and nothing has happened. I have had a couple of OLD cars with leaky valve cover gaskets over the years and never any issues other than some smoke, but not sure how bad this leak is on the LS, where exactly its dripping, or how hot an LS engine gets or if it could cause a fire on this particular car. I know all cars are different and have different heat sources, etc. I know oil is not as combustible as gas, but still I guess if it gets hot enough it would. Anyone ever had a fire on an LS400 because of a leaking VCG?

It puzzles me though that puff of smoke and the smell of the smoke. Most cars when VCG leaks have a steady amount of smoke and it has a distinct oil smnoke smell. It would be nice if some sort of additive could be added in the oil to ease leaking of the valve cover gaskets or if slightly tightening those rear bolts would help, but look like a pain. There is probably no easy way around this other than replacing them hmm?

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I've seen a few salvage LS400s in yards with burned engines. What caused it, don't know. Any oil leak though is warrant enough to repair, and the valve covers are easy enough to pull. I did mine with the timing belt change two years ago, nothing difficult at all if you know your way under the hood.

Do the spark plug tube gaskets and valve cover bolt gaskets too, they're usually sold as a set.

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IF you do do it please take lots of pics. A DIY write up would be great. I have been thinking about doing mine for a while, but I've never had the courage or time. It seems pretty simple but that doesn't mean it will be easy. ALLDATA says its about 3 hours per side. That for a competnat tech, so I would venture to guess a day or even a weekend dipending on your pace. I think it is simple enough not to screw up so long as you take your time though. BTW time on valve clearance adjustment is 6.6 Hours and I checked head gaskets just for a laugh, 12 hours for one 14 hours for both banks. Don't pop one of them!

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I've seen a few salvage LS400s in yards with burned engines. What caused it, don't know. Any oil leak though is warrant enough to repair, and the valve covers are easy enough to pull. I did mine with the timing belt change two years ago, nothing difficult at all if you know your way under the hood.

Do the spark plug tube gaskets and valve cover bolt gaskets too, they're usually sold as a set.

Sounds scary. Good thing I have full coverage. :) Well, I have seen one with a slightly burned engine... turned out very near the alternator. I would bet it was from the power steering leaking down in the alternator and it shorted out. One other I heard of that had a fire near the upper part/center of engine near the EGR valve on a 1993 LS.

IF you do do it please take lots of pics. A DIY write up would be great. I have been thinking about doing mine for a while, but I've never had the courage or time. It seems pretty simple but that doesn't mean it will be easy. ALLDATA says its about 3 hours per side. That for a competnat tech, so I would venture to guess a day or even a weekend dipending on your pace. I think it is simple enough not to screw up so long as you take your time though. BTW time on valve clearance adjustment is 6.6 Hours and I checked head gaskets just for a laugh, 12 hours for one 14 hours for both banks. Don't pop one of them!

I will, but I doubt I will do it. I know I will screw it up.

Check this link though if you didnt already... its a good step by step write up on this that another guy wrote up.... take a deep breath! :)

Changing valve cover gaskets on a gen 1 LS400.....

http://www.lexls.com/tutorials/engine/valvecover.html

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