Q for the OCI gurus

[RF Overlord]

My niece bought a '94 LeBaron GTC convertible, with the Mitsubishi 3.0 V6. I've been told this motor is notorious for developing bad valve seals, and, based on the way the car smokes on start-up and when you coast, I believe it.

With over 130,000 miles on it, what oil and OCI would you recommend? I was thinking at this point she should just use whatever dino is on sale at AutoZone, top it off when necessary, and change the oil and filter at whatever the max interval is from the owner's manual.

From the general condition of the car, I doubt it was given immaculate care...do you think an Auto-Rx treatment would be wise? She's still in High School and doesn't have a lot of money, so I don't want to risk doing anything that may not be good for the motor in it's current condition.

Any and all suggestions are appreciated...

 

[Lubricious]

Greetings!

I would drain and flush the cold engine with 1quart of diesel and 1quart of cheap oil for 5mins.
Then I would try a heavy duty dino like Chevron Delo 400 15w-40 or even better Pennzoil 15w-40, and see if your smoking problem decreases. An oil change of interval of 3000 miles is not unreasonable.
I realize it's winter, but these oils still flow.

 

[eldawg4100]

i would suggest a 2 bottle auto RX treatment then use a good dino. the engine is a solid one and will run for a long time. my GF had one 2 years ago and that thing had some power.....

 

[dustyjoe1]

I respectfully disagree with lubricious. I did that diesel flush deal with my old toyota pickup at 130,000 miles....the procedure works well at cleaning up the engine, no doubt, however, I had some serious valve tap issues after that...seems that the deposits were the only thing keeping the valve train quiet...took a few adjustments to get them reasonably quiet again. Regular oil and filter at 3 to 5k will work fine IMO.

 

[RF Overlord]

quote:

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Originally posted by crashz:

Delo, Delvac and Penz Longlife will clean and help reduce the burning. Run a few short intervals and you'll clean out a bunch of sludge. [/QB]

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Thanks, everyone...

My only problem with running the suggested oils is that we DO get some relatively cold temps (can get into the low 'teens) and I'm concerned that a 15W-40 will be WAY too thick for an OHC motor...I've seen it pour, it's like molasses...

 

[Steve S]

I would use Auto rx as it works ,it won't hurt the engine and it is on sale . Only oils with esters will do any cleaning.

 

[Dr. T]

Auto-rx or Delvac 1. And I'll bargain a guess that the perceived valve seal notoriousness is due to 1.poor maintenance or 2.poor oil (30 weights)

 

[crashz]

quote:

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Originally posted by Lubricious:
Greetings!

I would drain and flush the cold engine with 1quart of diesel and 1quart of cheap oil for 5mins.
Then I would try a heavy duty dino like Chevron Delo 400 15w-40 or even better Pennzoil 15w-40, and see if your smoking problem decreases.

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I disagree and agree.

Do not flush that engine with diesel! It will only loosen the deposits and lodge them into oil passages. To clean it, run some AutoRX. This will also help to rejuvinate the valve seals. Running it will not harm the engine, as the esters gently dissolve sludge. I've run it in a severely neglected car, and it performed beautifully, sealing up a leaky gasket, cleaning the sludge out and cleaning the ring packs.

If money is any issue, run some good diesel engine oils. Delo, Delvac and Penz Longlife will clean and help reduce the burning. Run a few short intervals and you'll clean out a bunch of sludge.