[RESOLVED] Whats wrong with my motor?

[marsh63]

last night i was driving home and was at about 4500 rpms when my balance shaft tensioner went out and the car started shaking violently at rpms over 3000 so i limped it home about 4 blocks.

i seamed to have lost all my compression in cylinder #3. now when i started taking it apart i checked to see if the valves were bent by taking the valve cover off and inspecting them. nothing they all seal fine. all the valves open and close good to. i cant really feel it pulling in air when i cover the spark plug hole with my hand either. i pored a little oil in the cylinder and still got nothing as far as compression.

i havn't done a leak down yet but i will when my neighbor gets home.

would the balance shaft belt be able to make me lose all my compression in #3?

what do you think i need to fix this?

what other test do i need to do to check to see if its my rings or not?

could one of my valves be toast or something?

any help would be great i need this car to work bad!!!!! thanks
if you need more info ask.

also before it broke i was pulling close to 20 psi of vac at idle. after it broke the idle would jump up and down 300-500rpms but it was at about 12 pounds of vac. any help would be great!!!

 

[Timechg]

If you vac is at 12 lbs it might be that your timing belt skipped and your valves on cylinder 3 are bent. Poor ignition/compression or fuel can be culprits of less than par vacuum. Tips on Reading Gauges: Vacuum Gauges Hopefully that helps.

 

[marsh63]

alright we just did a compression test every cylinder has 150 pounds but #3 has 0. and the valves dont look bent. and we also checked the timing and it is dead on. so is it the pistons?

 

[wolf20043]

You can have bent valves and not visually be able to see them even with the head off of the car. With zero compression, that would be first suspect. I had one head I had to fill the valve cups with liquid and watch for leaking out the intake and exhaust runners to find them.
Mike

 

[marsh63]

yep exhaust valves are done. we just did a leak down and all the air was leaving out the exhaust

 

[BUCK]

Sadly chalk up another one for the Balance Shafts - I'm SURE you'll do the BSE during this repair evolution.

 

[marsh63]

well on one of my exhaust valves had half the valve was missing so i am going to do a complete head rebuild this week and hopefully have it done by this break.

 

[Old Mitsu Tech]

When you are going back together with your engine, replace the auto tensioner and be absolutely sure you set it right or have it set right. Else you might be doing it again. It's a hundred and twenty dollars very well spent.

Good Luck

 

[marsh63]

well here is some pics.

my tensioner is about 200 miles old. the dumb pulley for the balance shaft thing broke(it was brand new from mitsu) so i think im going to finish yanking the motor out and do a bse so i dont have to deal with this problem anymore.

then ill paint everything so it looks real clean

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[EDT007]

Is it just me or is there damage to all the pistons in that pic from where the valves hit? If your going to yank the motor out I would do a rebuild. Just my $.02. Goodluck either way!

 

[booostedGSX]

+1 I agree, if the motor is already out and your'e dealing with a BSE you might as well do it all.

 

[TerribleTSi]

those marks on all the other pistons are valve reliefs, not damage.

 

[marsh63]

na the pistons all have good compression. the motor was rebuilt like 30000 miles ago so im going to wait till i get money for some wiescos. but in the mean time im going to run what i got.

im pulling the motor to eliminate the balance shaft. and to clean it up. this summer i plan on doing a whole new rebuild with better parts for more power

ill post up some better pics of the pistons once i get them.

by the way i didn't jump timing so there is no way my valves hit my pistons. all that happened was one of my burnt valves broke when the shock of my balance belt jumped teeth. there is no damage to the cylinder walls and no damage to the pistons either. the motor looks gross in the pics due to removing the head.

 

[BUCK]

Shame on you for not doing the BSE LAST TIME & let this be a lesson to ALL~! - BUT - How REFRESHING to see someone who actually drains Coolant PRIOR to jerking the Head - GEE... Like a REAL Human being... Like... God forbid... a REAL Mechanic or something?

 

[marsh63]

well i would have done the bse but lets just say i didnt own the car when it was rebuilt.

and i wish i could say i was a mechanic but im a 16 year old kid. i work at a body shop but its just common sense to drain it. well now im just waiting on parts for my head.

any recommendations on what i should do since i have the motor apart that dosnt cost a arm and a leg.

 

[EDT007]

4-layer Mitsu headgasket, ARP's, 3g Lifters, Valve stem seals. Most of which are $100 or less.

 

[marsh63]

ok i got the arps and the head gasket and new valves. where do i find the 3g lifters at? i also have the stem seals and the guides.

 

[BUCK]

I'm sure any number of our DSMTUNER vendors can help there - You're aware of course you CAN do BSE in Car - GOOD time to replace all Oil Seals on the Front Case, Water Pump, etc... SEVERAL good articles on all this in the Tech Section - & yeah I see NO DINGS whatsoever on those Pistons - Amazing, a 1G out there that may never have jumped time~!