Are most oil smoke problems on Monty's valve stem seals (or guides)?

[Gruni14]

I looked at a 96 SR last week. Fairly low mileage rig. Smoked when warm at idle, but didn't seem to when given throttle or driving. My thought was valve stem seals or guides, but my wife was spooked by it. Obviously I didn't have time to dig into it not owning the rig. What's the most common cause for smoking at idle that Mitsu owners see? I've done plenty of stem seals over the years on other makes. They didn't usually smoke at idle though, mostly on engine deceleration when oil can get sucked through the intake valve guides. What kind of a job is it to go on a DOHC Mitsu motor?

Thanks,


M/G

 

[IncorpoRatedX]

stem seals. almost always stem seals.

Also a good idea to check PCV valves, rarely, but sometimes, they can cause smoke at idle.

 

[evol911]

I have a 94 that smokes. Not while idling though. It idles with no smoke but if you blip the throttle after letting it idle for 10mins or so, there is a fairly decent amount of blue that comes out the back. I've had decent luck with the no smoke oil additive. Until I feel like doing a rebuild or putting in a 6g75 3.8l somehow I just run that stuff.

I'm almost positive the heads need to come off. Not sure if a spring compressor can get down low enough with them on. Lots'a gaskets to replace if you tear all the intake off but its a fairly easy job to do timing belts on these. Most people have trouble with the rear coolant cross pipe on the drivers side head.


OEM Mitsubishi is the way to go on parts.

 

[CanyoneroAZ]

+1 on the OEM parts.

You can change the seals without taking the heads off, but you need a specific valve spring compressor tool. I'll post up the part number when I get home for the proper tool. Don't try to do it without this specific tool. TRUST me on this one.

 

[CanyoneroAZ]

The correct tool is Schley Products Inc. #91400B.

 

[BOPOH]

all you need is Lisle 36050 Valve Keeper Remover and Installer Kit and 6' of 3/8" rope. When i did those on my Sport i averaged about 6 minutes per valve and that includes moving the rope from one cylinder to the next and turning the engine to compress it - fast and easy job (once you remove EVERYTHING about the heads) lol

 

[CanyoneroAZ]

all you need is Lisle 36050 Valve Keeper Remover and Installer Kit and 6' of 3/8" rope. When i did those on my Sport i averaged about 6 minutes per valve and that includes moving the rope from one cylinder to the next and turning the engine to compress it - fast and easy job (once you remove EVERYTHING about the heads) lol

I have that kit as well. I didn't have any luck removing the keepers with the Lisle tool, but it's a snap re-installing them with it. I need to do mine soon so maybe I'll revisit the removal again and spend a little more time figuring it out. Rope trick works too, but I use a compressor and hose set up to keep the valves in place while the keepers are out. Tomato, tomahto.

 

[nckwltn]

all you need is Lisle 36050 Valve Keeper Remover and Installer Kit and 6' of 3/8" rope. When i did those on my Sport i averaged about 6 minutes per valve and that includes moving the rope from one cylinder to the next and turning the engine to compress it - fast and easy job (once you remove EVERYTHING about the heads) lol

wow! I had a really difficult time removing the old seal... I average like an hour per cylinder.... that included a couple of cylinders where the keeper wasn't fully in, and the spring slipped past my tool and the keeper went flying while I had to track it down.

What did you do to get the old seal off?

but I use a compressor and hose set up to keep the valves in place while the keepers are out. Tomato, tomahto.

a few of my keepers were really stuck in place... such that I was able to compress the spring on the valve quite a bit before the keepers would come loose... I'd be concerned that if you broke the compression seal by opening a valve that the valve would fall into the now vacant cavity. Air is compressible, and given the surface area of the valve head, it wouldn't be too difficult to compress the air enough to open the valve.

 

[BOPOH]

wow! I had a really difficult time removing the old seal... I average like an hour per cylinder.... that included a couple of cylinders where the keeper wasn't fully in, and the spring slipped past my tool and the keeper went flying while I had to track it down.

What did you do to get the old seal off?

I used these, twisting and rocking the old seal back and forth. After it moves up a little used the long end to slightly pry it from the bottom.

 

[nckwltn]

I used these, twisting and rocking the old seal back and forth. After it moves up a little used the long end to slightly pry it from the bottom.

Sounds about like my method too.