1991 Mitsubishi 3000gt VR-4 - Oil burning

Messages
404
Location
Palatine, IL
Hi, my friends 91' VR-4 has 135,000 miles on it and he ran nothing but Mobil 1 10W-30 with an OCI of 3,000 all the time. His engine is souped up to about 450hps. His car smokes alittle at startup and says burns alittle bit of oil at full throttle. I was wondering if it's worth considering an Auto-RX treatment or would that not do any good for the valve seals or whatever is causing the puff at startup?? Also is there a better oil to use than what he is using now? Thanks guys for your expertise [Big Grin]
 
Messages
930
Location
Southeast
My '94 tercel smokes a bit on startup due to valve seals and Im about 500 miles into AutoRx treatment. Its hard to tell in the summer, but I dont think its really helping with startup burn. Its also hard to measure something like that. But I hear the real magic of Auto RX is halfway through the rinse when everything settles down, so we'll see what happens in a couple of months.
 

therion

Thread starter
Messages
404
Location
Palatine, IL
quote:
Originally posted by FL-400S: My '94 tercel smokes a bit on startup due to valve seals and Im about 500 miles into AutoRx treatment. Its hard to tell in the summer, but I dont think its really helping with startup burn. Its also hard to measure something like that. But I hear the real magic of Auto RX is halfway through the rinse when everything settles down, so we'll see what happens in a couple of months.
k, thanks.
 
Messages
9,448
Location
USA
First I am sure he drives the crap out of this car right? I do not know anyone with 450HP that does not use the power. Second higher RPM's and higher loading will always show more oil consuption. Third the vechile is 13 year old sports car. When you add all of these factors up some smokeing is too be expected. I am faily confident with all of the above said that most of it can be fixed!! Step 1: Do a piston soak with LC if you have it if not use B-12 Chemtool. Follow Molakules piston soaking instructions. Step 2: Change oil to a good non-synthetic oil and put on a new filter and Auto-Rx. FOllow instructions at the Auto-Rx site for vechiles over 100,000 miles. Step 3: After finishing the above steps test compression wet and dry if consuption or excessive smokeing is still present. This will determin if the engine needs a rubuild or if it is just the heads. These are nice cars. I always wanted one myself. By the time I could afford one they had quite makeing selling them. It is hard to find them in decent shape. The Turbo models that are still in good shape always comand a premium! I would think that this vechile definately deserves a chance with Auto-Rx. I mean what is the altenative?
 
Messages
3,709
Location
Chattanooga, TN
I have one of these, a 97 but with very low miles. The oil he is using is fine, I use the Amsoil 10W30 manual suggests a large range, up to a 15W40 for me. The 10W30 does well for me. Nothing to lose with the RX treatment however, it sounds like a rebuild is in his future given the car's history.
 
Messages
5,785
Location
Dixie
Mitsu has widespread, valve stem seal problems on this whole generation of engines, including those in the Eclipse and the Mighty Max pickups. They all start burning oil on startup after about 60k-100k miles - the oil leaks past the stem seals after shutdown. I had a local customer with a 3000GT who was doing fine in this regard, but the engine only had about 25,000 miles at the time. The solution is to replace the valve stem seals with an improved design/material. Your Mitsu dealer will be VERY familar with this procedure and can probably quote you a price without having to look it up. Tooslick www.lubedealer.com/Dixie_Synthetics
 
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