Blacktop 20V Sludge?

**3sgte** · 22-01-2007, 02:25 AM

Hello.

I have had a blacktop 20V Corolla Wagon for about 1.5 years now.

It had a fresh oil change when I bought it, and I have changed the oil in it 2 times since then.
I have put very few km on it, less than 12,000 in that time.

When I bought the car, I looked in the oil filler cap, and it wasn't pretty. Not scary, but not pretty either. Definitely a brown laquer color in there, with the metal still clearly visible.

Now, I check the oil, and it isn't as pretty as I expect, so I pull the oil filler cap off and there's been an accumulation of sludge!

Are these things known for sludge?
I have put a total of about 350,000 kms on other 4A/7A engines, and they have always remained clean inside.
I realize my current short-trip driving style isn't helping much, but geeze!

I'll be changing the PCV valve post-haste, I wondered of these things have a reputation or not.

I also heard someone else say that tensioners cause trouble on these.
How so?

**oldcorollas** · 22-01-2007, 02:34 AM

is it overheating badly?

**3sgte** · 22-01-2007, 02:37 AM

No overheating at all, it runs dead nuts perfect.

**Trekka273** · 30-01-2007, 08:36 PM

Sorry for bringing up an old thread, but I previously had a silvertop that we bought from an importer for use in an off road car. We stripped the engine as soon as we got it and it had lots of sludge throughout the engine, yet when we drained the oil we didn't really see any.

Could the sludge have been in your engine when you got it and is only just now working its way loose and depositing where you can see it?

**ViPeR_NiPPleX** · 30-01-2007, 08:44 PM

apparently its condensation. the second bt20v halfcut we got at work was a bit sludgy around the oil filler cap...

**Bananaman** · 30-01-2007, 08:53 PM

Originally Posted by ViPeR_NiPPleX

apparently its condensation. the second bt20v halfcut we got at work was a bit sludgy around the oil filler cap...

You're talking creamy sludge though? Think trekka means black sludge?

**3sgte** · 30-01-2007, 09:44 PM

In my case, certainly black sludge.
It doesn't appear to be at the point where I am in danger of having the oil pickup blocked, but who knows.

I will post a picture later.

I will assume that part of the issue is moisture and crankcase ventilation however.

All I can do is change the oil and PCV, if it grenades, then off to the scrapheap with it!

**oldcorollas** · 30-01-2007, 10:13 PM

ahh, the short trips, esp when cold, aren7t going to help the oil keep itself clean....

get it up to temp and take it for a decent drive every now and again, like an hour or something, to let the moisture and fuel in the oil evaporate..
if you only do short trips.. the crap never leaves the oil....

**Trekka273** · 30-01-2007, 11:07 PM

My own opinion, and it is just that, an opinion, is that in Japan they don't seem to ever worry about changing the oil, because they know they will have to change over the motor/car at fairly low kilometres, so they don't bother. Obviously with the extremely cold temperatures that they can get in Japan, when combined with old oil, causes a lot of sludge to form?

**oldcorollas** · 30-01-2007, 11:09 PM

nope, oil gets changed as per factory servicing...
in snow areas, most people seem to spend 5-10 minutes warming (while pushing snow off) and then leave the car idling whenever they go into shops.. and it takes 30 mins to get anywhere anyway

**Sam_Q** · 31-01-2007, 01:13 AM

maybe its worth looking into that trick of running some diesel through the oil to clear it out.

**ae86represent** · 31-01-2007, 08:28 AM

This is my sugestion, and is the same procedure we use when a customers car has severe sludge in the engine.

Drain oil, Fill car with diesel oil (Diesel oil has a far higher concentration of detergents than most petrol engine oils). Then purchase a bottle of 'Wurth Engine oil Flush'. Idle the vehicle for about one hour (No need to drive and definatly don't bounce the thing off the limiter).

Drain oil again, change filter (Use cheap one as it will only be on there for about a week). Fill engine with a high quality mixed fleet engine oil. (Again will have a higher concentration of detergents). Drive vehicle around for approx one week and plan a road trip somewhere, say about 2Hrs straight driving so the engine can get nice and heat soaked and the oil can get nice and hot and thin.

Drain oil after approx one week and fill with your choice of high quality engine oil, replace cheap filter with genuine toyota one. This should have removed a good portion of the sludge build up in your engine.

Cheers,
J.

**3sgte** · 31-01-2007, 09:26 AM

The main question I had is if 20V 4AGs are known for sludging.

4AFE and 7AFE of the same vintage are very much the opposite in my experience, no matter what you do to them, they will never sludge up.