Which oil? 1983 LeBaron 2.6l (Mitsubishi engine)

[Jazzy]

Hi,

I've recently bought a 1983 Chrysler LeBaron 2.6L (Mitsubishi 4G54???) engine with 81k miles on the clock.

I can't find anything definitive on what engine oil to use and have had lots of conflicting advice.. What I do know is the handbook states: "non-detergent and straight mineral oils should NOT be used,"

I have seen a Chrysler service update from 1989 saying that 5w30 is recommended for earlier cars from that point onward - apparently from a fuel-economy perspective. But that seems a bit think to me?

From my perspective, I want a decent oi and one that is friendly to flat tappets. I'm in the UK so then climate ranges from -5C to 35C at the very extreme. And an oil that won't encourage old oil seals and gaskets to start leaking.

Many thanks for any help

 

[skyactiv]

No need to overthink it, but maybe use Castrol Magnetic 5W30. Do you know if that engine needs the valve clearance checked and if so, the last time it was performed?

 

[Zee09]

I sent you some info directly

 

[hemitom]

Unfortunately these were not the most reliable engines , run 5w30 10w30 no thinner .

 

[zrxkawboy]

I would use a 5W30 high mileage oil.

 

[Chris142]

Unfortunately these were not the most reliable engines , run 5w30 10w30 no thinner .

This. I had an 86 Mitsubishi pickup with that engine. It gave me fits. Constant carb trouble, the valves had to be machined @35k.

Broke a crank @44k. And went to the scraper soon after.

 

[Jazzy]

No need to overthink it, but maybe use Castrol Magnetic 5W30. Do you know if that engine needs the valve clearance checked and if so, the last time it was performed?

Hi. I've no idea when the tappets were last adjusted so that's on my to-do list along with a full service. Car came to the UK in 2020 and it's had some work but I don't think any systematic approach at servicing.

Cheers

 

[Jazzy]

Unfortunately these were not the most reliable engines , run 5w30 10w30 no thinner .

Yes, I'm mindful of the timing and oil pump chains...

 

[harbor]

The Amsoil vehicle finder suggests the below:

 

[thunderfog]

Pics!

 

[Sumboodie]

I run 5w40 Rotella in everything.

 

[Chris142]

Hi. I've no idea when the tappets were last adjusted so that's on my to-do list along with a full service. Car came to the UK in 2020 and it's had some work but I don't think any systematic approach at servicing.

Cheers

Engine has hydraulic lash adjusters. No adjustments possible.

 

[addyguy]

Over in the UK, Magnatec 10W-40 would be my pick.

 

[Sandstorm]

 

[Tdbo]

I had a 1986 Lebaron T&C wagon with that engine. Always ran 5W30 in it for the over 100K I had it.
I'd suggest the HM version of the same.

 

[We're Metals]

Quaker State/ Pennzoil/ Supertech 10w-40.

 

[JavierH19]

Pretty much anything 30/40 grade will do. Just avoid sketchy oils like mannol.

 

[TomYoung]

View attachment 271395

Look at the oils this poster is using and give some thought as to whether this high viscosity oil has any place in that engine. My suggestion would be to use a 0/5W30 full synthetic oil and if you really need to go thicker, go to a xW40 version. Choose a decent brand and call it a day. An XW50 oil is against mfr recommendations and really not appropriate for the application. A full synthetic gives you most options and comprehends that we are 40 years on.

 

[SR5]

In Australia we use to run 20W50 or 15W40 in that engine.
Now days in the UK I would use something like Castrol Magnatec 10W40 (API SP, ACEA A3/B4).
Check the oil level regularly, Mitsu engines tend to burn oil.

Link to Magnatec 10W40 spec sheet below
https://msdspds.castrol.com/bpglis/...4EFFCF880258AB00041FE26/$File/wepp-cjrfnr.pdf

 

[nickaluch]

10/30 high mileage non synthetic could use a blend.Keep eye on oil level a known oil eater also leaks past valve guide seals.Puff of blue smoke out the tailpipe on a morning start after it sat on the overnight it's the valve guide seals.