damn, i can't believe it happened. i was hoping it to be just a nightmare but i'm wide awake! this is how it started, when the light turns green last night, my brother guns it, the rpm reached about 5k and a loud sound together with a sound of something dropping was heard and the engine stalled and huge smoke coming off the rear can be seen from the rear view mirror and sidemirror. we coasted to a stop and the car won't crank anymore. damn it!

this detonation only started last saturday, i gun it at 2nd gear and this wierd sound came up, i then shifted to 3rd and step on it some more. after that, it occured to me that the wierd sound was detonation after all! but after that, the car drove fine until last night when it blew up from doing WOT.

i took pictures of the oilpan last night and as you can see there are 3 damn holes on it like something came out of it. the holes are inline and i don't know what came out of it to make the holes inline.

the problem is:
1.) why did it detonated only NOW? i've been boosting for 3 damn months why only now? i didn't change anything? could it be my intake charge was so dense coz i wrap them with a/c wrap?

2.) if only the #4 cylinder/piston/connecting rod is damage, do i need to change the other 3 cylinders?

3.) what other damage do i have to look forward to?

4.) what do you think came out of the holes on the oil pan? the size of the holes are approximately 1cm in diamter.

by the way, car is a 99 SiR and the setup is:
-T28 turbo with int. wastegate @ 9psi
-intercooler
-synapse missing link
-8:1 fmu
-inline pump
-msd 6a with internal coil
-stock internals
-stock injectors

i was saving up for a vafc and injectors coz i'm planning to do the hack but detonation beats me to it! this is so frustrating!

any info will be appreciated.





[Modified by _Endless_, 4:13 AM 1/29/2003]

 

SO, you're running 9 psi of unintercooled boost on a high compression motor with stock injectors and a FMU for fuel enrichment sitting at a stop light idling building heat then you gun it car detonates and sends a rod flying through the pan. Do I got this right?

If you can hear detonation, you're in big trouble. I've run 18+ psi boost in my dsm and have yet to hear detonation, but its happening. I have datalogging capabilities and believe you me, i've detonated it pretty hard and i've never heard it. SO, imagine how bad it is when you can hear it!

Why did it happen? Dunno, but it sounds like a problem that has developed just recently. Is it warmer in your area now? Maybe you got a bad tank of gas? Maybe you got dirt in the fuel filter, or clogged an injector? Maybe you developed a boost leak, causing the air that actually reached the cyliders to be unusually hot due the extra cfm that puny t-25 has to pump out. Maybe your FMU isn't working right, got a fuel gauge? Maybe a fuel pump is failing.

As you can see, it can be a ton of problems. SOmetimes I take my knowledge of turbocharged cars for granted, i've been running a lot of extra boost for a long time on my eclipse without no problems because I understand how things should work together. Monitoring equipment never hurt either. Try to learn, try to get educated and better luck next time. Time for some upgraded rods now

 

no intercooler and a FMU at 9psi.. jesus dood you were asking for a blown motor.

those holes are prolly from pieces of your rod or rod bolts flying through the pan..

i guess u learned the hard way.

but now u can put some new sleeves in! woo ha!

 

i'm sorry i forgot to mention that i do have an intercooler. although i live in a tropical place, the weather is a bit cold during the night coz it's january.

i don't think a connecting rod flew out of the pan coz there's only 3 small holes on the oil pan and i'm trying to figure out what came out.

i guess what you said about not hearing detonation made sense and other factors as well. damn this is frustrating.

 

it had to be pieces of your rod or the bolt heads that hold the rod to the crank..


or mabey it was jesus?

 

probably a rod bolt flew out the pan

 

is there a chance that only the #4 cylinder/piston/rod was damage and cylinders #1,2 and 3 are ok? if so, then can i just overhaul the #4 cylinder?

 

You sure you just didn't spin a rod bearing or something? Detonation seldom results in throwing a rod.

 

Instead of asking us what happened open it up and tell us what happened. If you were detinating you shouldn't have been driving the car that aggressively . Stupid idea of your part. When it detonates and you can hear it you need to park it and wait till you can tune it better.

 

Judging by the looks of your oil pan, I would HIGHLY doubt that you only damaged the #4 piston and cyl wall...

 

I HEARD detonation can happen when the intercooler gets too cold..(some one correct me if i'm wrong) if that's not the case, it could be your rod bolts or didn't tune it good enough...





[Modified by hoya_10fintec, 5:00 AM 1/29/2003]

 

Exactly why I just installed an interheater for additional safety

 

i have never herd detonation and was wondering what it sounds like for future refrence.

 

what do you mean spun a rod bearing? what would cause it and how do i know?

 

Oil starvation / poor maintenance.

 

damn 9 psi with only a 8:1 fmu...... thats why it blew.... 12:1 for 7 and thats pushing it.

 

get a 10mm socket, wrench, extention and drop the oil pan. the damage will be obvious after you stare at the crank for a minute.

 

that's what i'm planning to do tonight rather take the head off. it's easier that way.

by the way, is it possible to replace the stock sleeve rather than rebore the cylinder? like in other cars where you can just replace the cylinder liner and still use stock piston?

 

8:1 fmu with stock injectors?

 

Yes.

 

if i were to take the cylinder head off do i need to take off the camshaft, cam gear, rocker arms and etc, or do i just take off the belt and take the cylinder head with all the components off?

 

you need to take out, the cam caps, cams to get to the head bolts...

you need to remove the valve cover, cam plate holder (for GSR), cam caps, cams, timing belt off the cam gears, Intake manifold, upper rad hose.
remove all head bolts, then there you go....

stan

 

Well, you live and learn man. You shouldn't have been riding it hard if you heard detonation. I am sure you have more damage than just the #4. Post pics. Good luck!

 

yeah i learn it the hard way. damn it still can't believe it.

i just hope it's only #4, if not, then it will cost so much to fix all cylinders. to cut cost down, i won't rebore or resleeve it to accomodate oversized pistons since it will cost very much from where i live, instead i'm going to put in stock sleeves to accomodate stock pistons.

 

You wouldn't have to worry much of that if you had a stand alone, right?????

I seriously doubt only the #4 cylinder is bad. You had metal particles go through your motor. You might as well strip it down, replace the bearings, whatever rods you messed up, replace whatever stock sleeves you messed up, and if others are messed up then look into golen eagle. For a little bit more buck, there probably a better way to go! Make sure you clean your oil pump very well, or replace it.

Let me know if you need stock pistons and rods. I have some pistons and rods off my '99 Si in the garage.
Good luck, David.