1G Turbo Pistons and N/T Pistons

[DSM_Crazy]

hey all,

my motor was rebuilt by a noob mechanic before i bought it.

heres my problem...im experiencing MAJOR blow-by. smoke comming out of my breather hose and oil dip stick tube...possible problems? maybe wrong pistons? bad rings? the current owner said he replaced the piston rings which leads me to the conclusion, maybe he has the wrong kind of pistons on it?? its a 90' eagle talon tsi awd.

is there a difference in size for the 1G turbo and 1F N/T pistons? or even possibly he has 2G pistons on there?? if so, would that be a cause for blow-by? i just got new rings from my friend but its 2G turbo piston rings. would that be ok on them?

please help me out!
DSM_Crazy

 

[timloomis]

Dont start buying parts untill you get it tore down. Do a dry and wet compression test first. It could be as simple as a plugged pcv valve or as bad as needing new rings/pistons.

 

[stagen]

The compression ratio is defferent between N/T and Turbo. Turbo has 7.8:1 and N/A has 9:1. If he put N/A pistons in it, it could have done some pretty bad damage to the pistons. I had exremly bad blow-by for the minute or so I managed to have my car running when I first got it. Once I tore it down I discovered that half the ringlands on two of the pistons were destroyed.

Do a compression test to check things out as previously mentioned, then tear into it to see whats going on in there before you go and buy stuff. Oh and dont forget pics if you find anything interesting

 

[->PrOjEcTGS<-]

My guess is that the guy didn't hone the cylinders out when he replaced the rings. Therefore the rings haven't seated properly and you are getting blowby.

 

[DSM_Crazy]

thanks for the input guys!

heres the thing...I have a bunch of shit disassembled and taken out. ex intake mani, exhaust mani, all the piping and hoses and radiator out... the original plan was to do a motor swap but i came acros alot of family and financial problems and stopped...so intead of ripping it out, i was planning on just fixing the initial problem im the kind of guy that barely has time to work on my car (maybe once a week if im lucky) so i do everything i can when i do.

i think I'll continue to tear it down just to see what im dealing with like maybe bad pistons or rings. can the turbo and N/T pistons be easily identified? maybe a code on it or certain shape? are they different in size where i can measure them with a venier caliper and tell which ones which?

thanks again

 

[DSM_Crazy]

My guess is that the guy didn't hone the cylinders out when he replaced the rings. Therefore the rings haven't seated properly and you are getting blowby.

i really like your guess and hope it might be my problem. my neighbor is a mechanic and has a honer. I plan on honing the cylinders this sunday. I'll also be able to see what else i might be facing once i get the head off and the pistons out

im lovin all the input im getting so fast. i never had a better, more reliable site like this.

 

[92_eclipse_GS]

im not shure but i think the turbo pistons are not only stronger but slightly bigger in diameter
dont hold me to it if im wrong though

 

[->PrOjEcTGS<-]

im not shure but i think the turbo pistons are not only stronger but slightly bigger in diameter
dont hold me to it if im wrong though

Same diameter (bore). Different compression ratio.

 

[92_eclipse_GS]

yea i wasnt completely shure and i figured a experienced DSM lover would correct me
while on the topic of pistons and honing and stuff
whats a good technique to use when changing pistons?

 

[->PrOjEcTGS<-]

yea i wasnt completely shure and i figured a experienced DSM lover would correct me
while on the topic of pistons and honing and stuff
whats a good technique to use when changing pistons?

What do you mean technique? It pretty much means pulling the motor and disassembling it!

 

[92_eclipse_GS]

like shortcuts or anything to make it easier on a teenaged kid

 

[->PrOjEcTGS<-]

The best time to learn is when you are young. Plus you really don't want to take shortcuts on an engine, especially if you want it to last.

 

[92_eclipse_GS]

yea good point
and if i ever get stuck i can hope on here and ask people like you for help

 

[DSM_Crazy]

yea good point
and if i ever get stuck i can hope on here and ask people like you for help

take an automotive class at a community college or something. its definetly worth it. you'll learn alot and gain so much from it.

my very first class, i ripped apart a transmission, alternator, starter, motor, and some other things and put them back together working properly. its worth the experience. im only 19 and taking much more classes this fall.

 

[DSM_Crazy]

Same diameter (bore). Different compression ratio.

so they have the same diameter..that means it wouldnt be a cause of the blow-by...would rings have a play? i have 2G turbo rings that were given to me brand new, not even touched. would they be ok on 1G turbo pistons? or N/T pistons?

 

[92_eclipse_GS]

take an automotive class at a community college or something. its definetly worth it. you'll learn alot and gain so much from it.

my very first class, i ripped apart a transmission, alternator, starter, motor, and some other things and put them back together working properly. its worth the experience. im only 19 and taking much more classes this fall.

im still in high school full time and lack the funds

 

[pazsion]

i'm guessing since the 1g and 2g are the same size in bore, that your rings for a 2g will fit fine. Honeing is recommended for a proper seating and to get any scuffs and scratches from the bad ones out. Lube up the cylender walls, compress the rings and slide it in. Move the piston up and down. It should give a little resistence as it slides over the oil, And not jiggle from side to side. test this as it goes up and down. You should not feel metal grinding metal.. and it should not stick throughout the stroke. I'm hopeing the previous owners haven't tried to bore it up one to the 88's.. or just taken to much out.. then the rings won't be meeting up with the wall. you may or may not have side to side travel. If this was the case, even after you hooked everything up, oil and gas would still be getting by and mixing with the oil.. and burning it off.

Smoke being forced out of the breather on the intake covers... could be bad valve seals. or guides... this would only happen during the compression stroke. And either the valve isn't seating right, or they are not sealed properly. replace all valve seals and guides to be safe. shouldn't be too diffficult. check and see if they seat right or are bent. might as well get a new head gasket set while your at it.

When you get it back together do a compression check.

should be 9-10+ n/a 7-8 turbo

 

[92_eclipse_GS]

i think im going to do this tomorrow

 

[DSM_Crazy]

Smoke being forced out of the breather on the intake covers... could be bad valve seals. or guides... this would only happen during the compression stroke. And either the valve isn't seating right, or they are not sealed properly. replace all valve seals and guides to be safe. shouldn't be too diffficult. check and see if they seat right or are bent. might as well get a new head gasket set while your at it.

When you get it back together do a compression check.

should be 9-10+ n/a 7-8 turbo

I also have smoke GUSHING out of my oil dip stick tube. its flying 2 feet in the air. the PCV valves purpose is to suck air out of the block right? i just changed my PCV valve incase it was plugged awhile back and running. that would also be why I have smoke comming out of the breather hose right?

When I do get the head off, I will take the time like you said to change the seals and guides for safe assurance. I wouldnt want to put the whole thing back together and find out I still got smoke gushing out

 

[92_eclipse_GS]

that would be a bi***
i hate taking stuff apart 5 times before its fixed

 

[DSM_Crazy]

alright!!!! finally had the time to work on my car yesterday WOOT!!

got the head off and saw some problem from my masive blow-by problem...

number 1 being one of my pistons (in port #4) was totally fried on one side. The oil control ring was blown into the piston itself. the top compression rings were fried also.

number 2 being (port #1) had valve seating problems. 3 out of the 4 were leaking oil into the chamber...

this isnt really a good picture but kinda visualize oil all over it

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I called a shop and they said they'd charge me 150 to get all the valves reseated and im going to purchase 4 new pistons, wrist pins, and connecting rods i guess. the shop said they'd charge me 80 total for them to install together. feels good to actual touch my car after 3 weeks of non stop working and auto class

 

[->PrOjEcTGS<-]

Wow! those aren't stock intake valves! Those are large!!

 

[DSM_Crazy]

i have no idea the current owner "supposedly" rebuilt the head. do you think he got the wrong valves? should i get them reseated or buy new valves??