1G Concerned about repair work done prior to purchase, need advice

nopistons93 · Feb 25, 2019

Issue needing advice: Feeling some vibration in the shifter in the common 3-5k range, no noticeable shaking of the engine or drivetrain.

Concerns: I just purchased the car and the previous owner said the timing belt was done recently. I inspected the belt and it does appear to have been done, so I'm concerned that the balance shaft wasn't timed correctly. Additionally the previous owner said motor mounts were done, they look pretty new but I can't tell the construction. Is it normal to have some vibration with stiffer motor mounts through the shifter? I free revved the motor while recording a video of it and it doesn't move in it's spot between 3-4k RPMs. Also driving on the freeway is fine, and I don't feel the vibration in the shifter in 4th or 5th as much as 1-2 gear.

Thoughts: Does it sound like my timing is correct and I'm just feeling the mounts? From what I understand, if the timing is off, the motor should be moving noticeably in it's place in neutral or in gear.

Thanks for the help guys.

pauleyman · Feb 26, 2019

nopistons93 said:
Issue needing advice: Feeling some vibration in the shifter in the common 3-5k range, no noticeable shaking of the engine or drivetrain.

Concerns: I just purchased the car and the previous owner said the timing belt was done recently. I inspected the belt and it does appear to have been done, so I'm concerned that the balance shaft wasn't timed correctly. Additionally the previous owner said motor mounts were done, they look pretty new but I can't tell the construction. Is it normal to have some vibration with stiffer motor mounts through the shifter? I free revved the motor while recording a video of it and it doesn't move in it's spot between 3-4k RPMs. Also driving on the freeway is fine, and I don't feel the vibration in the shifter in 4th or 5th as much as 1-2 gear.

Thoughts: Does it sound like my timing is correct and I'm just feeling the mounts? From what I understand, if the timing is off, the motor should be moving noticeably in it's place in neutral or in gear.

Thanks for the help guys.

Does the car even have balance shafts? If the balance shafts are wrong or have been eliminated you will likely feel a slight vibration at 3000 RPM give it take and again above 6000 RPM. Balance shaft spin at multiples of crankshaft Revolution. You will not see motor vibration with the naked eye. it is pretty obvious if a balance shaft is out of Faze. Yes aftermarket motor mounts will increase vibration. Even if the car is 100% correct you will feel more vibration with aftermarket motor mounts. I'm talking about a urethane mount not some stock replacement. If you want to be sure you have to line up all the timing marks and check the phase of the rear balance shaft. There is no other way. You should check with the previous owner and see if the car even has balance shaft in the first place. You could do this visually with the covers off as the front shaft will obviously be missing.

nopistons93 · Feb 26, 2019

Good points. One of the biggest issues is I bought it from the son after his father passed away. It was taken to a shop and had various things, like the timing belt and tensioners done, but the person I purchased it from doesn't know anything about DSMs. The father kept it 100% stock, so I'd assume the balance shafts are installed. I can take off the belts and open up the cover and check the timing when I get some free time. I also think I have the receipt from the shop who did the work, so I'll call and ask about it and see if they did urethane mounts (which would likely be my NVH issue).

Vegas Smith · Feb 26, 2019

Most likely it's the stiffer motor mounts, but it can't hurt to double check the timing/balance shafts.

nopistons93 · Feb 26, 2019

Thanks, I'm starting to think the same. I had it on the freeway today, stayed in 4th, and went from 3 to 4k slowly. I feel like balance shafts out-of-timing would feel way worse than how the motor feels, it's more of a "buzz" then a shake if that makes sense. I also confirmed that the shifter doesn't vibrate at all in 4th or 5th at any RPM.

streetraceboi · Feb 26, 2019

Im pretty sure the oil pump sprocket is 180* out of phase...causing that vibration

nopistons93 · Feb 26, 2019

Someone said that when their rear balance shaft was 180 degree out of phase they were snapping bolts on the drivetrain from it shaking so badly. Mine doesn't shake or move, just a buzzing type vibration which is really only felt in 1-3rd gear.

pauleyman · Feb 26, 2019

nopistons93 said:
Someone said that when their rear balance shaft was 180 degree out of phase they were snapping bolts on the drivetrain from it shaking so badly. Mine doesn't shake or move, just a buzzing type vibration which is really only felt in 1-3rd gear.

It won't shake. Just buzz. I did it on another Mitsubishi 30 years ago

streetraceboi · Feb 27, 2019

nopistons93 said:
Someone said that when their rear balance shaft was 180 degree out of phase they were snapping bolts on the drivetrain from it shaking so badly. Mine doesn't shake or move, just a buzzing type vibration which is really only felt in 1-3rd gear.

Yea theyre exaggerating and being over dramatic L O L Buzzing type vibration is what youll hear....oil pump sprocket is 180* out of phase

nopistons93 · Feb 27, 2019

Well then god damn LOL

. So what's my easiest approach here? Zip tie the belt to the cams at TDC then rotate the oil pump sprocket? I know there's no way to fix it without basically doing the belt but I don't need to pull the belt off completely. Any tips to do it easier and safely would be appreciated!

nopistons93 · Feb 27, 2019

Adding this interesting post I found to help me reference when I'm doing the repair:

"hey im not sure exactly what your talking about but if you mean your trying to align your oil pump with the timing marks this is how you do it.

1. there is a bolt on the side of the engine towards the firewall its next to the support for the intake and should not be holding anything on to the engine.

2. remove that and have the timing marks on the oil pump gear ligned up it will be facing the 9 o clock position and will lign up with the casting now you should be able to stick a screw driver all the way in that hole if its in the correct position if it doesnt turn the gear one revolution and ligned up again and check to see if it will go all the way in the hole now.

3. Then install the timing belt and dont forget to remove the screwdriver and put that bolt back in.

Also the timing marks on the oil pump gear will only line back up every so many revolutions so if it was right when you first put the belt on dont worry about that just make sure all the other timing marks line up every revolution"

seems like a good plan for ensuring the balance shaft is correctly lined up, assuming I can reach that bolt with the car jacked up.

1990TSIAWDTALON · Feb 27, 2019

You can get to it from the bottom. It is on a flat pad under the intake, in line with the balance shaft.

nopistons93 · Feb 27, 2019

When it comes to removing the T-belt, since I don't have to change anything out, and I able to just loosen the belt via putting a 1/2" drive into the tensioner? Ideally I just line up TDC, zip-tie the belt to the cams to hold position (assuming that's also correct), then push the belt off by putting pressure on the tensioner, line up sprocket correctly, then put belt back on. Seem correct?

nopistons93 · Feb 27, 2019

Just bought the tensioner tool from extremepsi, as well as a new balance shaft belt in case that wasn't changed. I don't plan on pulling the crank pulley, I've read that you can cut the old balance shaft belt off and basically rotate the new one on vice pulling the pulley off.

nopistons93 · Mar 2, 2019

Called the shop did the repair, he said he pulled the original belt off the car and kept the timing the way it was from the factory once aligned to TDC. Said he's owned 5 DSMs and is familiar with the oil sprocket/rear balance shaft and although he didn't check specifically, the only way the timing would be off is if it came that way from the factory.

He also said he noticed the vibration but wasn't able to track down the issue, there are still some original motor mounts on the car, so it's possible it needs all new mounts.

1990TSIAWDTALON · Mar 2, 2019

Any Poly mounts in the car ANYWHERE?

nopistons93 · Mar 2, 2019

1990TSIAWDTALON said:
Any Poly mounts in the car ANYWHERE?

The top motor mount and one of the tranny mounts were replaced, no word if they were poly but I'll look. Just an interesting development. I'm still planning on pulling the timing cover off, lining up TDC and checking for the rear balance shaft setting through the inspection port.

1990TSIAWDTALON · Mar 2, 2019

Well good on your part. The Poly mounts will DEFINATELY make the car BZZZZ. I replaced just the drivers side on my auto car and immediately noticed it. They transfer the motor right to the chassis.
My profile car has all 4 poly mounts and you can feel the engine for sure.

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