Best oil for 86 Bronco II?

[Sunabozu]

My truck has somewhere north of 310k on it, possibly as high as 410k, i was running castrol 10w-30, but it wasn't keeping the oil pressure up or keeping the lifters pumped up, so i switched to RP 15w-40 and that kept the lifters happy and it kept my mpg up, but it wasn't helping my sludge problem, and the stuff is about as expensive as liquid gold.

so yesterday, i bought a gallon of Rotella T6, 5-40 and filled it up, but i screwed up putting the filter on (forgot to pull the old o-ring off the socket and dumped all the oil out, last time i forgot the drain plug)

and i couldn't afford another fill of T6 so i had to go with the Regular Rotella T dino oil.

It's kept the lifters pumped up so far, and i haven't really driven it enough to know what effect it's going to have on the milage, but for the first time in a while the oil pressure is within spec, 15-18 pounds at warm idle, 50 at highway speeds.

Should i still with the Dino rotella, go back to the T6 next time i change, or is there some other oil that would be best?

Engine is a 2.9 V6, i drive it 70mph or higher on a regular basis, and i do some light offroading.

 

[Chris142]

Those 2.9's were always noisey. I figured that they had a mechanical valve train not hydraulic.

 

[Sunabozu]

nope, hydraulic, in my case the sludge reduces the flow through them and makes a couple collapse and get noisy.

edit: at least i think that's the reason.

 

[tomcat27]

according to my neighbor who has been a mechanic forever and has around 300k on his 2.9 - the valve seats are a little soft and the metal can crack pretty easy. glad ur seein good pressure

 

[Sunabozu]

well, another problem with the 2.9s is that every bit of oil pressure relies on the cam bearings, they wear out, oil pressure is gone.

 

[coffee]

I think MaxLife 10w40 would be ideal for your situation.

 

[Sunabozu]

I've heard bad things about valvoline...

will max life clear out the sludge better than rotella?

 

[postjeeprcr]

I would recommend an oil that will stay in your engine...lol

 

[Sunabozu]

Originally Posted By: postjeeprcr
I would recommend an oil that will stay in your engine...lol
so, an oil that somebody other than myself puts in it, eh?

 

[Johnny]

How do you know there is sludge in the engine? If you have upwards of 410K on it the regular Shell Rotella T 15W-40 would be what I would use. I don't think you will find anything out there with a better detergent/dispersent package in it. I sure would not waste my money on anyones synthetic oil. And don't put any additional additives in the oil either.

 

[Robenstein]

Maxlife is a good oil and have had luck with it.

However, a good Diesel oil will probably protect your engine better. If you want a good compromise between Rotella T and Rotella, you might want to track down some Mystik syn blend oil. I buy it at the local farm store for under 20 bucks for two gallons.

Those 2.9 engines were not great engines. The heads were crack prone and there was a brief period when there was an aftermarket for stock replacement heads because it was so bad.

 

[lipadj46]

Originally Posted By: Sunabozu
so yesterday, i bought a gallon of Rotella T6, 5-40 and filled it up, but i screwed up putting the filter on (forgot to pull the old o-ring off the socket and dumped all the oil out, last time i forgot the drain plug)


Out of curiosity why did you dump all of the rotella T6? I understand you had to get the o'ring off but why did you toss the perfectly good oil?

 

[Johnny]

Probably did not realize what he had done until after he started the vehicle and drove off. It does not take long to pump the oil out if the gasket on the oil filter is not right.

 

[lipadj46]

Too bad, it would have been nice to hear from someone who actually has used the new rotella T6.

 

[Kruse]

Originally Posted By: Chris142
Those 2.9's were always noisey. I figured that they had a mechanical valve train not hydraulic.


This is an engine that started out with mechanical lifters and was engineered to always have mechanical lifters. When they did the switch to hydraulic, a lot of the lifters were not quite getting enough oil, especially on a high mileage engine.
I guess the noise gives it character.

 

[OAS]

I usually use RTS 5-40 in my '90 Bronco2.

Last oil change i used Maxlife 10-40 out of curiosity (and kinda low funds at the time).
It seems to be keeping the oil pressure up, but next change it goes back to RTS anyways.

Those aftermarket heads are still available for the 2.9.
Ive got 2 of them on mine which got rebuilt about 20,000 miles ago.
OP, if youve got more than 200k on the oem heads you are doing VERRRRY well! Mine cracked at 150k.
They were so cheap i replaced them both.

 

[coffee]

I think the MaxLife will clean out your engine very well and will really be a good fit but Rotella is a good oil as well.

 

[Durango]

Since you have a sludge problem I'd have your motor flushed real good and try the same 10W-30 again. I'll bet the flushing will help if not cure the internals pressure up.

You didn't say if your consuming any more oil on a monthly basis although I'll bet you are.

Maybe you should consider rebuilding the engine???? With that many miles your probably due assuming the body and such is still in fantastic shape.

Durango

 

[Sunabozu]

Originally Posted By: Johnny
How do you know there is sludge in the engine? If you have upwards of 410K on it the regular Shell Rotella T 15W-40 would be what I would use. I don't think you will find anything out there with a better detergent/dispersent package in it. I sure would not waste my money on anyones synthetic oil. And don't put any additional additives in the oil either.



i had the valve covers off and it was reaaaaaaaaaaallly nasty.

 

[Johnny]

Well, not knowing the vehicle or the total condition it is in I'm not sure what recommendation to make. I do know one thing, with those miles and if it is reaaaaaaaaallly nasty, no chemical is going to clean it up. If it is a good vehicle, worth saving, and you intend on driving it for many more years to come, there is only one solution, rebuild it.