tonyjh63

Hey guys, I want to learn all I can about this "oil sludge" issue with my friend's 2000 RX300. I've changed her oil twice now, and the oil has been kinda sludge-y/brown looking, and not much drained out. So, can anyone point me to some links to read up on the problem? Is it a pcv issue? Too much blow-by? Thanks for any help/pointers!

hypervish

Sludge builds up due to lack of maintenance.

Toyota updated the PCV design and valve cover design multiple times, however you can prevent sludge by changing the oil on time.

If you want to check for sludge, pull the front valve cover and take a look. Oil color is not a good indicator.

tonyjh63

^^^Ok, let's say I pull the valve cover and there's lots of sludge in there...now what? Would that "Gunk" brand motor flush be a good idea? In other words, once sludge has built up, what's the easiest/cheapest way to get rid of it? Thanks!

P.S. She hasn't had it very long, so we really don't know how often the oil was changed...
P.P.S. Also, are there any updates I can do to the pcv system to help with this issue?

hypervish

Depends on how much sludge is in there. You can try Auto-RX but that's about the only additive I would try. Other additives such as the one you mention are too harsh , and will send chunks of sludge through the system. Which will cause more harm than good.

There's an updated rear valve cover but I wouldn't go through the trouble of installing that unless you are already doing valve cover gaskets or have an oil consumption issue.

salimshah

Please dont confuse oil patina (for lack of a better word ... this is brownish thin crust on metal part.

There are plenty of RX with old valve cover and PCV valve around without engine oil gel problem, so that change is not warranted (IMHO).

If the engine has been running without problems, I would not shock it. Take the oil pan out and clean it. Remove valve covers and clean them and switch to a good oil and change frequently.

Salim

jnovak01

I just pulled my front valve cover today at 140K and the inside was VERY clean. There was a l little sludge in the front left lower corner of the head. All told it was the volume of about 5 US pennys so really not much.

Question: with the front head that clean should I worry about the PCV venting on the back head? I would say I don't have to worry, but what is everyone's opinion?

Thanks

pilot2

When the valve cover is pulled, do you need new gaskets or are they the reusable rubber type?

hypervish

Always replace, especially on 1MZ-FE motors. These engines tend to run hotter than most and it really cooks the gaskets, they become extremely brittle. It's common for valve cover gaskets to leak on these engines, so if you are in there might as well replace it.

salimshah

Please separate the two issues, engine oil-gel due to infrequent or poor oil and pcv.

You have done the easiest of all to examine the oil gel. The back valve cover sits at a incline and has tendency to collect more (if present) oil gel and the oil pan (sump) which by gravity collects most of the gel. If you are serious about chasing or confirming or best yet eliminating the oil gel issue, check these two.

PCV is a painless check (rattle) ... be careful if you plan to replace the grommet. Read up about it.

Lastly if you are among the folks who is convinced that you need a new valve cover with a new pcv, then no amount of reassurance will work.

Salim

jnovak01

After consideration I decided to perform the job myself.
I Replaced the PCV and grommet, disassembled, cleaned and reassembled front and rear covers. New Plugs, plug gaskets and valve gaskets, along with the Bypass hose. Cleaned the intake and throttle body. Replaced coolant. Also checked the VVT Oil filter which was very clean. Total investment one Saturday and $50. Will post some pics as well. Thanks