1987 Montero, new head, mechanic says...

[PythonDR]

I have a 1987 Mitsubishi Montero, 2.6L I4 engine with 150k miles. I just installed a new head (2-valve to replace the notorious 3-valve "jet" head) and am currently breaking it in. The mechanic who supplied the head (and is widely considered "the" expert on this particular engine) told me to use a ZDDP additive during break-in, and suggested to continue using it as "these engines were designed for oils that had much higher zinc levels than oils do today." My interpretation of what he told me was the cam journals are not lined (bare aluminum) and thus need the extra boundary layer for protection.

Based on Mitsubishi's recommendations, I've always used 10W-30 (winter) and 10W-40 (summer) conventional oils from whatever major manufacturer was on sale. I change it every 5k miles and use NAPA Gold filters. Here in Oregon, temps can range from below freezing to over 100, depending on where I am and what time of the year; I generally pick the viscosity to suit whatever time of year it happens to be when I do the oil change. When I run out of my current stash of 10W-30, I'll probably settle on 10W-40.

After the break-in period for this new head, should I make a change in my oil choice? Should I continue to use a zinc additive or search out a high-zinc oil as he suggested?


(Edited to add, for clarity: the mechanic only supplied the head; I sought him out because of his reputation for building these engines and his access to the part. He assembled the head, shipped it to me, and I installed it.)

 

[hemitruck]

I would use redline after break in. Has the additives your engine needs.

 

[StevieC]

What about running UOA's after break-in with ZDDP and just plain oil and see if there is a spike in the metals?

 

[HangFire]

Originally Posted by StevieC
What about running UOA's after break-in with ZDDP and just plain oil and see if there is a spike in the metals?

You could do that. Or spend the UOA money on a ZDDP additive, and use it in small doses with the oil of your choice.

 

[maxdustington]

Rotella 15W40 year round and skip the additive?

If you can run 10W30 in the winter, is a winter oil even necessary?

 

[PythonDR]

Originally Posted by maxdustington
Rotella 15W40 year round and skip the additive?

I'd thought about that, then found the thread where T4 isn't approved for gas engines any longer. I'm still reading the debate...

Quote
If you can run 10W30 in the winter, is a winter oil even necessary?

I probably didn't explain that very well. It's actually more of not running thinner oil in the summer. My oil pressure at idle drops slightly with the -30 during the summer; since I have some to use up, I just relegated it to the winter oil changes. Don't have much left, and after that I'll use the -40 year 'round.

 

[PythonDR]

Originally Posted by HangFire
Originally Posted by StevieC
What about running UOA's after break-in with ZDDP and just plain oil and see if there is a spike in the metals?

You could do that. Or spend the UOA money on a ZDDP additive, and use it in small doses with the oil of your choice.

That's kind of where I was going with this thread. Running UOAs on oil that I'm going to change frequently anyhow, simply because of the very dirty conditions I drive in, doesn't seem a good use of my time or money.

 

[maxdustington]

Originally Posted by PythonDR
I'd thought about that, then found the thread where T4 isn't approved for gas engines any longer. I'm still reading the debate...
I was under the impression it was no longer approved because it contains the additives that old cars need but damage cats on new cars, such as ZDDP.

 

[StevieC]

Originally Posted by PythonDR
Originally Posted by HangFire
Originally Posted by StevieC
What about running UOA's after break-in with ZDDP and just plain oil and see if there is a spike in the metals?

You could do that. Or spend the UOA money on a ZDDP additive, and use it in small doses with the oil of your choice.

That's kind of where I was going with this thread. Running UOAs on oil that I'm going to change frequently anyhow, simply because of the very dirty conditions I drive in, doesn't seem a good use of my time or money.

A few UOA's will help confirm it and will help you establish a safe limit for the oil in your application where it seems to be crucial.

 

[PythonDR]

Originally Posted by maxdustington
Originally Posted by PythonDR
I'd thought about that, then found the thread where T4 isn't approved for gas engines any longer. I'm still reading the debate...
I was under the impression it was no longer approved because it contains the additives that old cars need but damage cats on new cars, such as ZDDP.

That's what I thought too, but then someone said it wasn't the case...and you know how those debates go around here!

If it were suitable it would make my oil inventory easier, as I run that oil in my New Holland tractor.

 

[PythonDR]

Originally Posted by maxdustington
Originally Posted by PythonDR
I'd thought about that, then found the thread where T4 isn't approved for gas engines any longer. I'm still reading the debate...
I was under the impression it was no longer approved because it contains the additives that old cars need but damage cats on new cars, such as ZDDP.

Found the definitive answer "from the horse's mouth":

Shell ROTELLA brand has made the decision to remove API SN claims, regardless of viscosity, from our other products which do not meet the preferred low-phosphorous chemistry for gasoline engines. It is important to note that there is no change in formulation associated with this change. It simply means that Shell ROTELLA products will no longer claim formal API SN approval for products other than our fully synthetic Shell ROTELLA T6 Multi-Vehicle 5W-30 on labels, technical data sheets, rotella.com and marketing materials moving forward.
- The Shell Rotella Team

So, I think I'm going to be stocking up on Rotella T4!

 

[dave1251]

Originally Posted by hemitruck
I would use redline after break in. Has the additives your engine needs.



And off the shelf oils don't?

 

[dave1251]

Originally Posted by maxdustington
Originally Posted by PythonDR
I'd thought about that, then found the thread where T4 isn't approved for gas engines any longer. I'm still reading the debate...
I was under the impression it was no longer approved because it contains the additives that old cars need but damage cats on new cars, such as ZDDP.




What old car needs greater than 800PPM ZDDP? Nothing stock.

 

[DoubleWasp]

I've seen plenty of engines that were sparkling clean on the inside (indicating no neglect of oil changes) that has badly gouged bare cam journals. I would run an HDEO for that motor. 15w-40 for good weather, and 5w-40 for winter. Keep a good oil film between that cam and the journals. A boutique oil is hardly called for. Maybe if you had a tuned up turbo version.