Toyota V6 5vz-fe engine sludge

[pwuser154350578554]

Salam. I'm in sort of a sticky situation here..quite literally

Recently bought a 2004 prado 3.4 v6 4 speed auto. The car is clean from the inside out except a few things here and there..however, after buying it i noticed a slight ticking noise at low rpm (up to 1.2-1.3k rmp, after which the noise just went away or maybe muffled). The average i was getting was nearing 5km/l (on normal and heavy foot driving mixed up) which is considerably low (what should the average be? Please comment!!)
Either way, at first i thought it was because of ganda petrol so ran it on v-power for a couple of tanks. Bump..its still there the noise. The engine had 80000 kms on it when i got it. The 100k mark was nearing so i figured it's time to change the timing belt and get the valves readjusted. Before this i had the cat converter, throttle body and MAF sensor cleaned, changed oil(used zic 10w40 synth), oil filter and air filter.

Got her opened up (which apparently is a pain in the ass for this engine) and got it replaced along with bearings and all. The water body was leaking a bit so changed that. The bearing on water body bracket (the one to which the "clutch" of the fan and belts are bolted) was a bit noisy so got the bearing replaced. Eveything went smooth.

However, the real knife to the heart was when we opened her up to adjust the tappets. The engine was badly sludged due to previous negligence. The previous owner was running 20w-50 grade engine oil (God knows why). Attached are the pictures of the internal conditions. The internals were badly sludged and it really was depressing and painful to look at. Cleaned as much as we could by hand without loosening big chunks and dropping them inside. Replaced the tappet cover seals and closed her up.

Although she runs much smoother now, is perhaps giving a marginally better fuel average, and purrs much better like a v6 should) i still can't get my head around the fact that theres still so much sludge at the base of the tappet heads..(who knows what the chamber, and internal oil filter looks like) in short, it can still perform much better IMO.

Now i don't want to get the engine block removed and get it all cleaned up. I'm still pretty new to the gasoline engine stuff. Always kept a diesel and never let it get dirty from the inside.

What can i do to make her run better? Without damaging the engine with excessively harsh motor oil additives and engine flushes. Counting on the vast experiece of the members on this forum to ease up the situation here. I'd be very very grateful for comments regarding this situation

Before

Other head

Tappet cover before

Cleaned up by hand as much as possible

Thank you!

[pwuser154350578554]

It's worth mentioning here the it's an embassy auctioned car so it's very much possible that the car was very very poorly maintained at their end

[sleeper]

Just my understanding;

I believe the sludge (black thingy) was formed due to running on a very old oil...meaning the oil was not changed for atleast 20k kilometers......someone correct me if i am wrong
.
Plus the water body/pump usually lasts 100k atleast....i believe the engine doesn't have geniune 80k mileage on it and its much more than that
.
Lets see wht experts say

[akifjanjua]

that kind of mess can be caused by lack of oil flow. Do check the oil pump and oil lines for any blockage/restrictions.

[SpeedDemon]

Adding gear oil is considered to be an good engine flush. Some brands like liqui moly also have such products.

But flushing engine is not recommended because it could loosen some oil seals in the engine and lead to major repairs.

Try some short oil change intervals with a good oil. Fully synthetic and keep the engine on High Octane.

Also keep an eye out for oil reduction. Always warm up the car in this weather and check the exhaust for funny smoke colors or smells.

I know Toyota pretty much makes their cars idiot proof, but Pakistanis are a class above !

I would also check the plugs. If this engine has a one coil for firing two cylinders (wasted spark ignition), then it requires a Denso Double Tip plug (ND16 heat range, not ND20). Do confirm this beforehand.

Cheers.

[pwuser154350578554]

Thank you for the useful replies and comments.

I believe the vehicle has genuine mileage because it just doesn't look, feel, or sound like an very high mileage vehicle..but then again who knows. When getting a used vehicle in old models, this is something you're signing up for, no? About the water pump, it wasn't very very leaky, and the engine wasn't reducing any coolant either..got it replaced just so wouldn't have to do it again later.
Either way, we're past that point now and overall i'm happy with how she runs..OVERALL haha

Ill get the oil pump and lines checked for restrictions next soon yes. But i think that requires quite a while to get to. It won't hurt to run it like this for the next 5-10k km i hope. Nonetheless it shall be checked whenever possible.

Trying the short interval oil change approach. Shall cut open the filter to see what its like from the inside on next oil change. Keeping it on 50/50 octane/super mix for now. That can be changed though if i can find a better mix ratio.

Keeping a keen eye on oil and coolant levels. Its been 3 days since getting it done and changing oil and coolant. The car has been driven around 300km with no visible oil and coolant reduction. Always warming up the car before running it. That's like a standard practice. Unless time is short, in which case a couple of minutes to get the oil running is fine perhaps?

The exhaust does give some white smoke (which does smell a little..strong.. Please elaborate what you mean by funny) when the engine is cold but it disappears as operating temp is reached and as far as ive assessed theres very little to no exhause smoke when running). The plugs were replaced by previous owner. Genuine denso spark plugs are running (the two point ones) and there are no signs of wear or color changes on them as of yet..

Apart from that, adding ATF to oil isn't too bad for the engine is it? I've read many positive reviews about that if used in appropriate quantities. However, if anyone here with personal experience could further clarify it, it'd be very helpful. Im just a bit reluctant because never tried it before. And just maybe i can push myself to do it. I'm pretty sure nobody wants any leaking seals, specially internal ones. They're a pain in the ass to replace i reckon

Regards.

[VCheng]

That engine is still serviceable. I would suggest dropping the oil pan and cleaning the oil pickup strainer and the oil pan itself, followed by regular 5k oil/filter changes with a good full synthetic oil. That is all.

[SpeedDemon]

Blue smoke on startup could mean weak oil seals on the valves (valve seals). A longer blue smoke duration on cold start could mean weak rings. I think you are safe from these issues.

A sweet smell of unburnt fuel is normal on cold start. Other smells like the smell of coolant could be water seeping into the engine because of head gaskets (again I think you are safe from that).

The octane requirement of your engine determines the correct mix ratio. Regular fuel in Pakistan should be 91 and HOBC should be 97 octane. Mix according to the octane you desire.

As mentioned by VCheng, regular oil changes with a good oil should keep you safe and worry free.

I am just mentioning all these diagnosis points because one does not know how the car was maintained before so a thorough investigation will keep you safe rather than sorry.

Happy Motoring!

[rajaahmed96]

I would rather use fully synthetic oil like Shell Helix Ultra 5W40 and it will clear up all of this mess. Drain it early like for 3000-4000kms for two oil changes then drain it at 8000kms with toyota genuine oil filter. Runing a quart of kerosine with old oil will also help clearing up stuff when you change the oil and drain it just run it for 15 mins on idle.

[ulislam1997]

You should definitely drop the oil pan and get the oil pickup and stuff serviced and the pan too.
Can vouch for the early oil change method. I recently got a car with a swapped but then neglected for sometime engine. And although there wasn’t much sludge per say, I did however measure the disgusting oil that came out of the engine which was 2.5 liters at maxx where as the engine requires 3.7-3.8 liters. I’ve been doing oil changes at 2000 kms just to be extra safe and since this car is driven very little each month and performance and the condition of oil that comes out each time has improved slightly.

[Xulfiqar]

welcome to toyota - where sludge is a way of life.

clean out the sludge as much as you can from the valvegear and from the oil sump and strainer. Make sure your engine can get to normal 95C temperature in under 5 minutes from cold start. Run a full synthetic 10w30 oil in it and change filter every 300 kms, twice. Then run the oil for another 1500 kms and change it with full synthetic again and change at normal 6000 kms interval.

Replace the PCV valve with new toyota part and make sure the vent on the tappet cover is clean and good working condition. There should also be no leaks anywhere in the engine. - If your engine suffers imminent damage to lubrication failure then rebuild the engine. - hopefully it wont.

Another point to think about is the headgaskets, Oil gel also forms when coolant is very slowly mixed with oil - the oil gel sometimes looks like this slugde.

[maazam01]

@pwuser154350578554 if you do not mind how much you paid for the SUV.
Thank You

[imrankhanmsb]

This post was flagged by the community and is temporarily hidden.

[dr.atherkal]

What do u mean by one coil for firing two cylinders??