hypervish

Your fine, 3k and Castrol GTX is fine. You don't have a sludge motor in any of your cars so your fine even with 5k.

hypervish

Both. 5k is a bit much on conventional oil for this engine ( runs hot, and small oil passages).

You can guarantee that no sludge will accumulate if you use synthetic oil and change at every 4.5k.

I play it safe and change my synthetic oil at every 3k, maybe at most 4k. But, I drive the ball bags off of my RX.

TriniLex

How many miles was on it?

crankshaft

Also...keep us posted.

Iluvlexus

Wow, that really hurts. I had read the horror stories of gelling and PTF (premature transmission failure) on this forum prior to and during my search for an RX300. A few months ago I looked at a 2 owner that had 135K. Owned since 68K, did his own oil changes, and had never given him any trouble. Terrific condition inside and out.

I looked under the car and it was dry as a bone. The engine compartment was reasonably clean. I pulled out the dipstick only to discover that the oil was a half a quart below the add line. It was quite dark but flowed OK. I showed the owner the dipstick and he was surprised the oil was low and claimed he had never added make-up oil. I believed him as you first have to check the oil to know you need some! Further questioning reveals that it was bought as a CPO at 68K miles and never saw the dealer again. His OCI was between 6-8K and he used the Walmart brand “fully synthetic”. There was about 7500 miles on this oil change. I pulled out the transmission dipstick and the fluid was brown. Level OK. No burnt or foul smell but not what I wanted to find. Obviously the transmission and timing belt were not touched under his watch. So I’m thinking this is a no-go, but came all this way and I’ve got to drive it. Starts right up, and drives great! Lots of power, a little sliding from 1st to 2nd, but quite solid. Rides like a 50K mile car. If I hadn’t looked under the hood and subscribed to this forum I would have written him a check without hesitation. He says make him an offer and after adding a quart of oil I drive it home for $6500.

I immediately changed the oil and filter to PNZ Ultra and a Baldwin B 243. I had the timing belt, water pump, thermostat, spark plugs, PCV valve and drive belts replaced. I research sludging and decided on Auto-Rx. I never pulled the valve cover to assess but just assumed I had it. At 136K I changed the oil to Castrol GTX and added Auto-Rx. I also did a transmission service with a pan drop, filter change and an 8 quart fluid exchange as prescribed by TunedRX300 in his sticky and added Auto-RX to it as well. Of note was that the filter was not stock. Somebody had been there before. That was definitely a good sign.

At 1000 miles into this intervention the oil was a beautiful light amber and had dropped at most 1 mm from full. The transmission fluid was dirty but still obviously red and the shifting performance was very similar to when we bought it.

I am now at 1500 miles into the Auto-Rx and can safely say that I have a good engine. There is no noticeable oil consumption and the oil has barely changed color. It may be my a change in my driving style, but it seems that the engine has more power. Is the Auto-Rx cleaning the ring-packs? The transmission is definitely shifting better since the Auto-Rx. The fluid looks fine. I plan to do a synthetic fluid exchange with a new filter and call it a day. This vehicle may have a long way to go! I am not sure all of the reasons that some engines gel, but it is likely that the high percentage of highway miles, synthetic oil, and a strong constitution may have saved this engine. The transmission, who knows?

Iluvlexus

As a disclaimer. I have no affiliation with Auto-Rx. That said, I think it works and believe it helped my transmission. The following is a link to a pictorial showing the effects of Auto-Rx on a sludged engine http://www.auto-rx.com/rms13/thumbnails.php-album=1.htm. I used to think this was a nasty engine, but Sanjonmomo's looks a lot worse. I seriously don't think any amount of cleaner will help and worry that once you loosen up the crud it will plug everything up. Best to bite the bullet and change out to a good junk yard engine. This is a terrific car and a good engine will help you enjoy it.

lexus114

What about pulling the heads and soaking them? That should work.

Iluvlexus

I saw a video showing just that and it did indeed clean the heads, but with oil consumption like sanjonmomo describes leads to a situation with very dirty oil and periods of reduced oil volume and pressure which do a job on the valve guides, rings and bearings. Even if he gets it cleaned out he will likely have an old, tired engine worn much more than the mileage would suggest. Still think it is better to take the money and invest it in a clean salvaged engine.

lexus114

Yeah, if he can find one, that would be the way to go.

Lexmex

He'd either have to replace the engine or overhaul it. However, doing the Auto-RX first is a cheaper, easier step to see where the engine is at afterwards.

boxbrownie

Always puzzles me when I read about the woes you chaps over the pond have with sludging, I sympathise but I don't understand what the differences are, I have never had any vehicle with sludging like you seem to get and yet oil changes here are usually always to the recommended intervals (usually 10-12K miles) and using a run of the mill semi synthetic nowadays, but a few years ago with just dino oil.

I cannot believe driving conditions vary that much....or can they?

My RX is just about to have its 90K service and a belt change along with discs and pads this Friday, but having looked inside the rocker box using an endoscope it looks as clean as a whistle in there.

Usually I would put sludging down to cheap oil/over long oil changes/engine never warming up properly......but you seem to do longer journey mileages than over here in the UK and seem to change the oil as soon as the engine gets warm Every weekday my commute is just 26miles to work and back home with maybe a 100 or so at weekends occasionally, oil changes at 10K and almost never needs topping up between......and the full 200bhp is used as often as I can

Is there a correlation over there with sludging and weather/location?

Odd...very odd.

I do hope you find a cheaper cue for your problem than a replacement engine though, good luck matey.

Lexmex

I am first curious what kind of oils you use. Some European oils have been fantastic for me and others.

The best correlation I can give is related to type of driving behavior and type of oil used. As long as the oil can get heated up enough (meaning not a lot of short trips that don't get oil fully up to temperature), sludging issue should not be an issue. Additionally, we have had members who used dino oil and have had no sludge issues, but their driving patterns are such they would avoid it. There have been occasions when I have been out of town on travel (and that's been frequent and not often driving) that my RX300 sat for two weeks or more. I used synthetic and vehicle would start up without a hitch later. Again, the most likely behavior that I see causing this is a combination of using a cheap oil and having driving patterns that don't get the oil fully warmed up...then I can see issue for sludge. You also have to throw in going very long on oil changes and neglecting the maintenance. I have met people that literally have told me Lexues are perfect and need little in the way of maintenance. To me, I just feel do your regular maintenance and you won't encounter the likelihood of a bigger issue later, unlike other vehicles.