Hello everyone,

A few months ago, my 2004 LS 430, 181k miles, developed a ticking noise on the left side of the engine. About two weeks to a month later it started one day with a cylinder misfire and flashing CEL. After taking it to the dealer it developed a misfire in all the cylinders, a flashing CEL, and VERY rough idle. The only codes to show up were misfire codes for all the cylinders. I posted about this issue when I was trying to initially diagnose the problem here. https://www.clublexus.com/forums/ls-...ew-engine.html

After moving out-of-state for the summer I came back this Fall and got a OBD2 cable and TechStream, and noticed hundreds of misfires at idle in cylinders 6 and 8, which would drop dramatically when revving to above 2,000 rpm. Unfortunately I did not have the time to keep trying to find the issue, so i took it back to the dealer (Cavendar Lexus of Lubbock) where they then determined it to be a blown head gasket using a boroscope and inspecting cylinders 6 and 2. In an attempt to verify this, I got a Combustion Gases Head Gasket Tester from AutoZone, and tested for any combustion gases in the cooling system through the radiator. The testing fluid was supposed to change color from blue to green/yellow, however I saw no difference in color as it remained blue. I then got my own boroscope and inspected cylinders 6 and 4, and did confirm it was a head gasket due to moisture in cylinder 6 and much less carbon deposits (I could see the features of piston 6 whereas piston 4 was an even layer of dark deposits).

As far as I know the car never once overheated. I bought it at 179k from an independent dealer, which claimed the previous owner to be the mother of a Lexus master tech, which he owned for the last two months before I owned it. The car was very clean on the inside and had no issues when I bought it. There was a good maintenance history at the dealer as well. Timing belt was done at 120k. However, I did abuse it a few times and stepped on the gas at low speeds, attempting to "drift" a few times, which I believe may have caused enough stress on the engine to damage the head gasket? (Not sure just guessing)

Due to time and money constraints, I decided to try a head gasket sealer to temporarily fix the issue. I know this is not recommended, however I used a product with good reviews, and was planning to replace the head gasket anyways, either now or later down the road if it worked. After some research I used the 32oz Blue Devil Head Gasket Sealer. Unfortunately it did not make any noticeable difference; the car still has a rough idle and flashing CEL.

First, I would like to ask, could it be possible that a head gasket leak as bad as this not be detectable any other way than through visual inspection, and not be affected by a head gasket sealer, yet cause such a bad misfire? My car shakes very roughly when idling. Could there also be another issue along with the head gasket causing this? I will post some videos of my car running from earlier this year, and many people in the LS430 Facebook group said it could be a crankshaft bearing.

Secondly, I am planning to replace the head gasket myself, mainly as a learning experience. I have nothing to lose by attempting it as it would hurt too much to sell this car for less than half the price I bought it for, especially it being my first car. I asked about an engine replacement, and the only shop that would do it is 5 hours away in Dallas and quoted me 3,900. So I would much rather do this myself and learn along the way. I also plan to replace the timing belt and water pump while I am there, and possibly also spark plugs.

After looking at lexuspartsnow and calling my local Lexus dealer, it seems and Engine Overhaul Gasket Kit, Part number 04111-50200, would have all I need to replace all the seals. I will also get an AISIN TBWP kit. total cost would be over $500. Is there anything else I would need?

I am 21 years old, and have only been working on cars for a year, however I would say I am mechanically inclined and have a passion for this as a senior mechanical engineering student. I am confident in my ability to do this, but only with the right resources. Looking at this thread below from a person with a similar issue a few years back, there seems to be a factory service manual. Anyone know where I can get a pdf copy? I tried looking on this forum and couldn't find a link to a PDF.

https://www.clublexus.com/forums/ls-...ad-gasket.html

Lastly, would I need any special tools to do this other than basic tools? I know I may have to machine the heads if they are not straight, but want to make sure that I won't need anything else for disassembly/assembly .

Thank you all in advance for any guidance and help with this.

 

First thing is that head gasket sealer contains sodium silicate which is a form of cement. You poured liquid cement in your engine the idea is for it to solidify in all the right places. If you're fortunate it didn't solidify properly destroying your engine. I personally will not work on any engine that has been treated with these types of head gasket "fix" products. I've seen them accumulate in coolant passages I could chip pieces off which means over time more will fall off and float around in your coolant. You might be lucky and the engine didn't get hot enough for the product to cure properly.

With that out of the way first thing needed is a compression test. If you find one or more cylinders is bad then perform a leak down test. If you do end up buying that gasket kit check the price on Amayama. Head gasket job is not for the faint of heart it is a lot of work with many steps. You MUST check the block and cylinder head surfaces for flatness using a precision straight edge if you don't and the heads and/or block is out of spec your repair will fail.

 

Thank you, definitely will check for flatness after taking the heads off. Would I be able to clear all the head gasket fluid and gunk from a coolant system flush or two? The product instructions called for a 50 minute idle, so the engine did go up to operating temp. However since it did not work and the engine didn't seem to overheat I am hoping it didnt leave much behind in the coolant passages or radiator.

 

I don't know of any way to clear that crud out, over time as you run the engine basically. Good news is those products tend to not solidify properly in other words they often don't work. You'll know when you see the block. Get the factory service manual here
https://techinfo.toyota.com/

That Toyota gasket set has almost every gasket in the engine, if not all of them. You'll need a valve spring compressor and ideally valve seal removal tool. Another way to remove the valve keepers is a hammer/magnet tool someone here can recommend the exact one for your car. I never got around to buying one I use the old school compressor tool, I'm used to it.

 

A guy from South Korea sells service manuals on eBay. The guys has 3 versions that I cannot tell differences. Here is one of them https://www.ebay.com/itm/20453510311...mis&media=COPY

 

Buy a used engine at this point.

 

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