I'm a newbie 2002 RX300 owner. Actually I bought it last September from a Lexus dealer in Denver. It had 82,500 on it and had just been serviced. I now have 89,000 on it and have not changed the oil. Yea, I know better, but I promise not to go that long again!

I'm concerned about all the info about oil sludge I've read, particularly since I went this long to change the oil. The car had been serviced religiously by the previous owner at the dealer. As far as I know they used regular oil (not synthetic).

I'm going to change it today using Mobil 1 and a K&N 2009 oversized filter that I read about on this forum.

Questions :

How could I check if I have any sludge problem and how hard is it to do? My mechanic abilities are very basic.

If I can't check for sludge easily, should I do an engine cleaning treatment on it as a precaution? Auto-RX? Other options?

How many miles can I go safely on synthetic given this engine is prone to having a sludge problem?

Thanks and BTW this forum is fantastic! I've learned a lot from it. Special Thanks to the contributors that go to great lengths to provide detailed answers.

 

Well,not to scare you,but that was a big mistake to go that long on an oil change in the 1MZ-FE motor. As far as the sludge is concerned,You can take of the Lexus cover, (the L emblem will turn cc) and a couple bolts,and off comes the plastic cover. Then, just remove your front valve cover,and see how it looks. (I should do the same,just too lazy.And too cold out rite now anyway) As far as oil, I would recommend the German Castrol 0W-30 (if you can get it) or the Penn Zoil Platnum. It would probably be a good idea to just go ahead and do an auto-rx treatment. I am getting ready to do one myself.(hence,my other post on here) Hope this helps you.

 

I am at 160k miles, and I have used a synthetic blend until about 90k and since have used full synthetic. by the way the German Castrol Oil 0-30 appears to clean the inside of the engine. I noticed the crust dissappeared on the oil filler area...

 

I run Mobil 1 0W30 (fully syn)with a Mobil oil filter and change around every 5k without any problems. With Dino oil I wouldn't go past 3k, 3.5k if you like to push the limits. Some people with syn are changing their oil every 7.5k, but I don't like the thought of that with the tendency for sludge in these engines.

I also only fill up with Chevron gas - It's top tier and has Techron in it which I hope helps out a little (visit toptiergas.com to find other service stations with top tier gas)

 

I wouldn't panic over the mileage right now. I lived at high altitude, too, and usually what I got was more consumption than anything like sludge, because I would drive just like anyone else (maybe even harder). Sludge often depends on how you drive it and not as much on the oil used, though you always want to have the best oil possible. I am not as much as fan of Mobil 1 myself due to experiences, but then again I have drived and still drive in a way different from most RX300 owners.

A mechanic might be able to charge you a small fee to remove the front engine cover to get underneath and see (you don't need to drain the oil to do this) and see just how clean it is underneath, BUT let me say the following.

If the previous owner was religious (and we don't know how they drove) and you just hit 7,000K miles, chances are strong it's quite clean.

With Mobil 1, I'd probably only go 5,000 miles, 7,000 miles for German Castrol 0W30. Other good oils I'd keep in mind are Pennzoil Platinum and Amsoil is also outstanding. I'd favor the Pennzoil over Mobil 1, but keep in mind the German Castrol is fairly priced (actually about the same) and Pep Boys and Autozone carry it.

 

The valve cover removal/check sounds pretty easy to do.

Question: I assume I should use a new gasket when I put the valve cover back on? Should valve cover bolts be torqued? If so, at what setting?

If it looks squeaky clean I think I'll skip the Auto-RX. If it looks bad I think I'll post a picture for some advice........
......OK, Cancel that.I just read up on Auto-RX at their site, Club Lexus and several other sites. This stuff seems to be the Real Deal!

So...My new plan is:

Drive 2-3K (@ 2-3 months) on my Mobile 1 I just put in today. I can't justify throwing out $25 worth of oil!

Next change:
Remove front valve cover. Based on what I find do an Auto-RX Basic Application (link) or Heavy Sludge Application (link) .

Switch back to Dino. Lexmex isn't the first one to suggest to me Mobile 1 isn't all it's cracked up to be. No offense meant to those who do use it - I've used it on and off for 30 years. I'll probably go with the German Castrol 0W-30, but depending how expensive it is I might use cheap oil to do the Auto-RX. The Auto RX site even recommends that. (link)

Question: Do any of you use the Auto RX Maintenance Application? (link)

This is kinda off the RX300 topic, but:
Meanwhile I think I'll do an Auto RX Fast Track Application (link) on my '89 Ford F250. It's got low miles (about 90K) for an '89, but about 90% fully loaded, pulling trailers, etc. It will be interesting to see if the Auto RX and switching back to Dino help my very leaky rear main seal. (common with Ford trucks )

I'll post back with what I find on the RX in a couple months. Thanks to all for your answers and opinions!

 

@alaskaty:

Question: Do all grades of Chevron have Techron? Based on a lot of Internet reading I just switched to regular gas. I know Shell's super-duper additive is only in their V-power Premium gas. I just ran through a bottle of Techron bottled additive and planned on doing that or BG 44K every oil change. Maybe if I use Chevron I wouldn't have to mess with that.

 

German Castrol cost about $6/quart last time I checked and it wasn't that much difference from Mobil 1 (same price or close enough to it), but Pep Boys or Autozone are the only ones that carry it. Mobil 1 is an okay oil depending on how you drive, but having had the chance to try German Castrol vs. Mobil 1 back in Mexico and no seeing the issues that I did with Mobil 1, GC was a winner in my book. I had have to see something with oil analyses of new formulations of Mobil 1 to convince me otherwise.

You don't have to put a new gasket back on. I have the same original gasket on mine despite taking it off a few times.

Yes, all Chevron has Techron. My girlfriend has an Expedition that runs 87 octane Chevron (I switched her off to this from some non big-branded 87 octane), while I myself run the 93 octane from Chevron. I favor Chevron over Shell any day. Only other gas I really like is Sunoco.

 

Like Lexmex said, ALL Chevron has Techron in it. I think only the high test Shell has the V-power in it, but the lower grades still contain enough detergents to receive a "top tier" rating.

Chevron is my go to, but I'll use Shell as a good second choice.

The reason I use Mobil 1 is that I tried a couple of the fancy low volume oils (Red line and Royal Purple) in my Typhoon compared to Mobil 1 and alwayls kept going back to M1. I haven't noticed any problems with the RX and the ES so I'll probably just keep on keepin' on. That's not to say the german Castrol isn't good stuff (people rave about it), but I can get 5qts of M1 at WalMart for $26 and it's right down the road.

Another side note: when I would use GM Top End/Engine Cleaner on my Typhoon (similar to sea foam) I would change my oil and my plugs because I found that if fouled them...don't know about AutoRX though.

 

BG 44K is strong stuff,I wouldnt use it every oil change.

 

My godfather still has his Typhoon, that's one amazing machine for its time.

 

You may have no use for this info, possibly ever. You might though if you ever find "yourself push't up agin sum olt Amurkin IRON" and you need to help.

Start with the oil you intend to drain....been in there a year that anybody recalls. Dirty? You bet. Add one gallon of Diesel or kerosene for every 5 quarts of crank case capacity. Start the engine and let it idle at a fast idle of 2K(for gas engine) till the engine gets nice and warm. Drain completely and for quite a few minutes. The stuff that comes out will be scary. Refill with new oil and run it for a thousand or 500 miles. Before doing the second change add a quart or so of Laquer thinner to the crank case of a cold engine and run the car down the freeway( constant load rpm) and get the oil temp up quickly....15 minutes in most cases. This will disolve varnish and keep it in suspension till you immediately drain when you get back from that 25 minute trip. Get it warm fast as you don't want it sitting in there and it evaporates at 140 degrees so it is gone by the time the oil gets to operating temp but you want it moving fast in the engine so it gets around proper. You change filters in this proceedure at appropriate intervals and you can drain the first dose of dirty oil and start with a fresh load. This has been an annual PM on every car I have ever owned since 65...all manner of domestic, Datsuns, trucks, Mazda and Lex. (Lex gets a quart of D)

There is nothing you might want to put into an engine to stop a leaking rear seal that would be a good idea. Particularly in a auto trans. Whatever the chem that "swells" the rear seal will swell every other blessed seal or piece of rubber in the thing. That is NOT GOOD. It leads to rapid failure and if it doesn't it didn't have those "swell" chemicals in there anyway. Don't ask me how I figured this out without any outside interderence.

Synthetics do not wear out and they do not contribute sulphur and other stuff that makes sludge. Water vapor from the combustion mixing with oil contaminants and additives make sludge. Dino needs those chems more than syn. Try this: at your next oil change interval draw a sample of your oil and send it in to be analyzed....use Catapillar's service or don't bother. They will give you more info than you ever wanted and half will be useful and understandable. Too dirty for the reported miles, cam metal in it, water, glychol and on and on. should end with a recommendation: no need to change, oil detergents exhausted and sludge formation emanent, high acid (bye bye bearings) and on and on. Real value is you can see parts of the engine wearing and the annal warns you of impending disaster with a history. You may also find that you can go twice as long between oil changes and then again maybe only half as long. Nice to be doing these things according to condition and not by rule of thumb.

Ok start caling me a "Phoul" and a "Krak Paught"

John

 

@JohnEd - I really appreciate the write-up and advice. There's a lot of info here. To be perfectly honest, some of this sounds a little radical. No, I don't think you're a "Krak Paught", but I'd have to research some more before trying some of the things your recommending.

I like the idea of getting an oil analysis - and I would do it on my F250 since it's a workhorse - but I plan on selling or trading it real soon. I'm gonna keep this in mind for my next tow vehicle though. Don't think I'll do it on the RX - we're pretty easy on it and I plan on doing frequent oil changes from now on.

I went and re-read about stopping a rear main seal leak with Auto RX. According to their website AutoRX will clean the seal and switching back to Dino will re-condition it, stopping or at least slowing the leak. It doesn't sound to me like AutoRX will actually swell the rear main or any other seals. BTW, the F250 is a 5 speed stick 4WD, not an automatic.

Once again, Thanks for the write up!

 

@lexus114 - Thanks. I'll remember that.