Hey all,
I have a question regarding the issues on some of the RX's regarding engine sludge.

Has anyone actually had any luck with having the dealer do a diagnosis to see if there's any sludge in the engine(or whether it's prone to sludge in the future) if that's even possible?

Does anyone know how many engines were affected? approx

Lastly, is the warranty still in effect or is it that after the 8yr or whatever it was..you're out of luck. Curious if anyone had to file a claim after the warranty period and had any luck.

Reason I'm asking is that...our 99RX is approaching 90k, and I really don't mind doing the t-belt, waterpump service etc, but don't really want to drop $1000+ and then be faced with other more serious issues that can drain a wallet.

Thoughts? let me know

 

If you havent had any problems and have kept your oil changes up you should be ok, I would suggest a synthetic blend or all synthetic as extra insurance to prevent the sludge.

 

I agree with thomas,and if your not having an oil consumption problem,or blue (oil) burning smoke from the tail pipe.You should be okay.Keep in mind that if your using regular fuel,that will retard the ignition timing,hence a hotter running engine.(sludge) more prone to build on a hotter running engine.I personally use Synthetic oil since around 78,000 miles with excellent results.

 

One sure way to know, remove the front valve cover and check it out. I did and the relief of knowing that there is no sludge is priceless.

 

^^ This is the best way of knowing. Prior on acquiring my RX. I had them pull off the front valve cover just to make sure. Also doing an oil change before purchasing it. 115k miles.

 

I'm in agreement with Tampa & Nad- It's easy to pull the valve cover to see what it looks like inside. I recently pulled the front cover on my DIL's Rx300, didn't actually expect to see sludge but was kind of puzzled at what I did see. Zero sludge, but areas of almost cinder baked on different areas in the upper head area and also in the crankcase area. (pulled the lower pan off) The rest of the total (inside of engine) area was just the varnish that is so typical of these engines. I still say these engines run hot in the crankcase. The car has always had regular oil changes with quality oil (but not synthetic). Don't know why it decided to deposit the "cinder" randomly where it did but it was hard just like cinder. Car has 120k and runs like a top and uses no oil!

 

Code58,That`s why I think synthetic oil in these motor`s,is definitely a good idea.The more you can reduce the friction to run cooler,the better.If you do use regular motor oil,I would change @ every 3,000 miles.

 

lexus114:
If you are finding that your engine is running hotter on 87 you must have some other problem that is causing it. I am on my second RX now, with 127k on this one and only use 87. I did experiment with different grades but engine temp always remained constant on both RXs.

 

Hey mikey how are you doing today,In response to your findings,some times you can`t really tell by the temp guage.I know that sounds contradicting,But think of it this way, it all depends on how much the timing in(degrees)is in retard.It is however a fact,that the engine will operate hotter when timing is not correct.(via retard status)And,it will not produce the max fuel milage/power.Now,I have been around engines for many years,worked as a GM mechanic,so I`m just trying to make some sense of this for you.Again this all depends on how many degress the system retards itself.That`s why I am not positive either that this adds to the sludging problem.Maybe we can take a poll here,and see who has had problems with sludge,and what octane they used.(probably would be best if they owned the vehicle from new.Also,maybe the engine thermostat should be a few degrees cooler.And climate where people live has it`s affects as well.

 

I realized you just joined, but sludge has been beaten to death here before, back when it was a much more common issue than today. You can do a search on it if you want to read any of it. It supposedly has more to do with the temp difference between the head and the block more than the actual engine temp. There were also surveys done on octane used before. I can't remember the actual numbers but well over 50% used 87 without anyone even mentioning temperature. And of course we are both just guessing here but I would be more concerned with a cooler thermostat causing sludge rather than preventing it. I am just not convinced that 87 vs. 91 octane varies temp at all. I have 127K on nothing but 87 octane and no sludge whatsoever when it was checked. I do like the idea of a survey of all the sludged engines looking for any commonalities. I just don't think we have a big enough audience of sludged engines here. Toyota/Lexus certainly could do it, but I think they are more interested in burying it.

 

You got it,the heat between the block/head. And as i mentioned,sludge is more than likely not caused by regular unleaded.I might switch to regular myself.But you really only save around $3.00 filling up with reg.That is why i didn`t change to it yet.(notice i said yet) depends on what the future price of fuel rises to.

 

Mikey- Hope I'm not discounted because I'm a "newcomer". I'm retired now but I spent my life in automotive (and I'm still learning) I don't think crankcase temps and coolant temps NECESSARILY go hand in hand. The modern aluminum radiators and electric fans do an outstanding job of cooling the coolant- what is the last time you saw a properly maintained cooling system run hot on the current type of systems. No matter the age of the vehicle if the system is maintained. But I think the crankcase does run hotter on some vehicles, and though I do agree with using synthetic oil, I don't think the difference in different engines temps is going to be cured simply by using synthetic oil, as a matter of fact you are probably not going to see the higher crankcase temps show up on the temp gauge of a modern car for the aforementioned reasons. They have truly learned how to keep the COOLANT cool. You are going to see those higher temps show up in the hardening of seals in the crankcase area and the coking of the oil on surfaces in the lower end and maybe even in the head area. The synthetic oil will likely deal with those temps a lot better than dino. Sludge is more than just a simple one issue matter. Have you ever seen a pan pulled that had hospital jello set in the pan? I have- it just had the color of used engine oil, and the true consistency of hospital jello- you could cut it into cubes. And not from vandalism either. A Honda Accord. A lot is known about gelling and some that is still to be learned.

 

I know we can all agree on this.

Prolong oil change intervals = sludge/oil gell build-up.
This will happen on any motor.

Got a buddy of mine than changed his oil in his Prelude every 10k miles and is hard on it. Pulled his valve cover and there was at least 1/4" sludge over the cam caps!! YIKES !

Frequent oil changes is the only way to combat sludge. I do mine every 3-3.5k miles.

 

Sorry, not try to discount anyone as a newcomer. Just trying to justify my not re-hashing sludge again by pointing out the at lengh discussion may have taken place before someone has joined. Toyota/Lexus sludge was very active a few years ago. A lot of cases here and on the other forums , even some investagative TV. The number of sludge cases has really died off recently. Maybe we are all better educated about doing frequent oil changes with quality dino or synthetic in these engines. I agree with everything you said on engine temps but was just pointing out that I don't believe using regular has anything to do with causing sludge in this engine.

 

I appreciate the reply mikey- and I didn't take it personally. I have a pretty thick skin anyway I totally agree with what you just said in every point. No one has ever pulled a pan plug on a vehicle of mine in my life- except me! I have maintained 3k mi. oil changes my entire life with top grade dino oil though I do believe that these engine (especially the RX) would definitely benefit from a good synthetic. I believe the same engine (the 3L.), because it is used in so many different applications, MAY NOT have the degree of problems in most of the other applications because it is not taxed as hard in them as the RX. You have an engine (and trans.) that was designed essentially for a family sedan (I realize it was used in the pickup and probably others that are not family sedans) used in a vehicle that is several hundred lbs. heavier and lower geared, and it simply taxes the eng., trans., and oil in a way that is not particularly good. From what I have read about the sludgeing and gelling problem it was primarily a crankcase ventilation engineering problem. I also believe that may be what contributes to the high crankcase temperatures. When they realized their mistake that's why they were able to end the S&G problems (though reluctantly, if at all, admitting that they created the problem). There are a # of other auto manuf. that have had the problem- just not to the degree that Toyota did and never became well known like the Toyota problem. Roger