DSM quirks and faqs
 

There are plenty of sites out there that talk about DSMs. In fact there is so much info it is easy to get lost and forget some of the basics.

1. The 4g63 is an interference motor. That means if the timing belt fails the valves crash. Possibly destroying the head, or poking a hole in the pistons, or throwing parts at your turbo and killing that as well. The timing belt is definitely the Achille's heal in a DSM. And they are only good for about 50k. You might be able to push it past 100k, and some probably have, but is it worth the gamble.

Also, the timing belt job on these motors is tricky. A lot of people don't bother setting the hydraulic tensioner right. What does this mean... a belt that fails at 10k or less. And most shops don't do the balance shaft belt at the same time which will break and take out the timing belt with it. Not to mention the idler and tensioner pulley that can and will seize if not replaced along with the belt. Also oil leaks in and around that area that will also affect the belt.

*Please add to this list with insight or personal experience. NO DSM bashing is allowed. Let's get some facts, on here with some troubleshooting tips or tricks. Thanks!

2. 90 model year had an air-cooled oil cooler while all the other models afterwards had a coolant-cooled oil cooler which are known to come apart. The problem is the part that the oil filter scews onto loosens and causes the oil filter to back off. Many people have lost a motor/turbo due to this.

Not to mention the the coolant-cooled oil cooler units have a tendency to get squashed and leak internally causing oil and coolant to mix.

Best fix is to upgrade 91+ DSMs to the air-cooled oil cooler units. Still, motors with cams, removed balance shafts, and stiffer motor mounts are not completely immune. Another solution is to add a hose clamp around the filter to help lock it down to the block.

What no mention of lifter tick :lol: A very common problem for all DSM's. Lifter tick can cause a "phantom knock". 50 wieght oil can help, but I'm not a big fan of running that heavy wieght of oil. The 3rd gen revised lifters are the best way to fix this problem.

listen to what he said, i just had to replace some of my head because of the damn timing belt.

agreed. I would check that oil filter everytime i get gas. I personally have not had this issue yet

Back in 92 my first DSM started to experience lifter tick around 50k. I tried ALL the snake oils at Pepboys/Autozone/Napa/etc. The only combo that worked was Mobil 1 10w/30 with RESTORER engine restorer in the silver can. I'm not sure how heavy weight oil can fix it cause lifter noises are caused by the hydraulic lash adjuster getting sticky. I even tried castrol 5 or 10w/50 and it didn't work.

Another problem with using heavy weight oil is it will wear the oil pump faster.

Still the best fix is getting 3rd gen lifters, like mentioned above.

Lifter noise will cause phantom knock and cause the ecu to retard timing, sometimes so much the car feels like it lost 100 hp.

Why are all the DSM threads in the 'japaNeSE JdM' forum?..I understand that you have a mistubishi forum but DSM's were built in the good ol' state of Illinois..Will,are you on philadelphiadsm by any chance?..

DSMs were actually built in Normal, IL and all the sheetmetal probably came from Detroit. In fact, if I remember correctly, Dave Buschur, DSMs biggest celebrity at one time, use to work at the plants that pressed the metal into shape.

Except the motor, tranny and 90% of everything else came from Japan and Mitsubishi. And in just about every book it is considered an import.





I'm 2point4 on PhillyDSM. :mrgreen:

Yeah, I went through this problem. Only thing that fixed was going to 3rd Gen Revised Lifters. Haven't had a problem since.