Cleaner or Additive?

[landtoy80]

Looking to keep my 94 Land Cruiser with 436,000 mi running for more miles.

History, I either put lots of miles on it from commuting or it sits for months at a time either just driving a few miles a week or no driving at all. Been using Rotella T6 with LM Motor Oil Saver. It is used 1 qt after 1800 mi, 1 qt after 1100 mi, 1 qt after 900 mi, 1 qt after 800 mi, 1 qt 900 mi and 1 qt after 700 mi.

I drive about 500 mi a week right now and planning a trip to AK from CO this summer.

I believe that the blowby is more than the PCV can handle and the oil is getting contaminated. I am working on better evacuating of the crankcase.

I get startup smoke. Its a large cloud unless I add LM Motor Oil Saver.

Compression Results 436,000 mi
Dry - Wet
#1 135 - 145
#2 145 - 160
#3 140 - 160
$4 145 - 150
#5 150 - 170
#6 155 - 170

Per Factory Service Manual
New 171 psi or better
Min 128 psi
Max between cylinders 14 psi or less

From a test on 6/2006 292,000 Dry- Wet
#1 155 - 165
#2 155 - 165
#3 155 - 165
#4 155 - 170
#5 160 - 180
#6 165 - 180

Loss of PSI in 144,000 miles of driving from 292,000mi to 436,000 mi Dry- Wet
#1 20 - 20
#2 10 - 5
#3 15 - 5
#4 10 - 10
#5 10 - 10
#6 10 - 10

I am going to go to a dino oil with a 3000 mi oil change interval.

My question is, should I just keep using an oil additive or would I want to try a motor cleaner or ring-free cleaner?

 

[kr_bitog]

I believe your case is similar with one of my car, i think the main issue is not with stuck ring but more on worn valve seal. In this case cleaner will not do much and perhaps will make consumption worse, i think the best is thickener additive or oil with lower will help to make it last long. The only caveat is be patient when warming up the car and it may increase fuel consumption a bit.

 

[expat]

How difficult would it be to install new vale seals on that engine?

Using a high mileage engine oil might cause the seals to swell a little. It could help.

 

[mehullica]

Use a leak down tester & diagnose where it's leaking from. You'll know in 1 minute if it's rings, intake, or exhaust valve seats that are losing compression

 

[demarpaint]

I doubt 3K dino runs will do much of anything, ask me how I know. You could try a piston soak, it might help. It's certainly worth a try.

With that kind of miles on the engine, it might just be tired and need of some work.

 

[andyd]

Blow by is from worn rigs, the smoke upon start up is worn valve /guides. You could rig a catch can for the blow by, and keep using the goo for smoke. At 436 K, I would be very hesitant to do anything except keeping it full of oil. How is the oil consumption, BTW?

 

[landtoy80]

After an oil change it uses 1 qt after 1800 mi, 1 qt after 1100 mi, 1 qt after 900 mi, 1 qt after 800 mi, 1 qt 900 mi and 1 qt after 700 mi, 1qt 500 mi.
Thus why I want to not do extended oil changes. As the oil gets old, its consumed quickly, I dont like that much oil going through the motor. With a 3000 mi change, its only 2 qts used vs municipal quarts.

Have to remove the head to do valve seals, big job and costly.

 

[demarpaint]

Originally Posted By: landtoy80
After an oil change it uses 1 qt after 1800 mi, 1 qt after 1100 mi, 1 qt after 900 mi, 1 qt after 800 mi, 1 qt 900 mi and 1 qt after 700 mi, 1qt 500 mi.
Thus why I want to not do extended oil changes. As the oil gets old, its consumed quickly, I dont like that much oil going through the motor. With a 3000 mi change, its only 2 qts used vs municipal quarts.

Have to remove the head to do valve seals, big job and costly.


Is the oil thinning due to fuel dilution? That could be a reason why the consumption increases as the oil is in service longer.

In another thread Trav laid out how to do a piston soak. I'd give it a try, you have nothing to lose. If your rings are coked up it might help, and help quickly. No long drawn out processes.

Originally Posted By: Trav
First things first, take a compression test dry then wet. With so few miles on it it might well have stuck rings.
My suggestion would be to run a can Berrymans Chemtool in the oil at idle only for 20 minutes then shut it off, do not drain the oil yet.

Remove all 8 plugs and pour a couple of ounces of GM top engine cleaner down each plug hole, reinstall the plugs lightly and leave it site a day or even 2.
Remove the plugs, crank the engine a few revolutions with a socket and ratchet on the balancer bolt.
Reinstall the plugs, drain the oil and refill with cheap dino. Fire it up and run it at 2,000 RPM for about 5 minutes then let it idle for 30 min.
Change the oil and filter, run it a few days and check the compression again.

After all that get some Kreen and run 16 oz in the oil and fuel, leave it in the oil for a about 1K and do another oil change with filter.

It can be applied to a 4, 6 or 8 cylinder engine.

 

[Trav]

With 436K you dealing with worn parts not sticking parts IMO. I would feed it oil until i was ready to either put a long block, do a rebuild or do a MB OM617 swap.
The L6 is easy to rebuild, it is a strong engine.

 

[krismoriah72]

It was in the 1980s i think when i heard the best advice that still holds true.. My fathers oldsmobile (i know joke).. smoked and used oil.

He took it to our local garage and asked how much to put a motor in it...

"whats wrong the motor thats in it".."uses oil and smokes".."you look like you are smarter than me..so go figure how much it costs to keep adding oil to it and come back if its more than $1000 and i will put u a new motor in it"..

If it were my vehicle i would run 15W40 in the summer and 10W30 in the winter and keep an eye on it and start saving money if u want to inframe it. The mystery chemicals aint gonna help ya here i dont think...with those kind of miles shes been good to ya and shes tired.