Please help identify this sound from my motor.
#1
Junior Member
Thread Starter
iTrader: (1)
Join Date: Aug 2011
Location: Queens, NYC
Posts: 150
Total Cats: 6
Please help identify this sound from my motor.
Hey guys,
Well I have managed to it again. The newly rebuilt 1.8 motor (94 bottom, 99 head) I just put in went pop the other night. I am pretty sure it was because of overboost (~14psi on a gt2560) at part throttle and after several similar incidents over the course of a couple of months something just gave out.
The car was still able to running but it sounded like a tractor. Compression test results are 190, 190, 180, 130. Can you tell what is broken from the sound?
Here is a sound clip:
Thanks in advance.
Well I have managed to it again. The newly rebuilt 1.8 motor (94 bottom, 99 head) I just put in went pop the other night. I am pretty sure it was because of overboost (~14psi on a gt2560) at part throttle and after several similar incidents over the course of a couple of months something just gave out.
The car was still able to running but it sounded like a tractor. Compression test results are 190, 190, 180, 130. Can you tell what is broken from the sound?
Here is a sound clip:
Thanks in advance.
#5
Elite Member
iTrader: (5)
Join Date: Oct 2011
Location: Detroit (the part with no rules or laws)
Posts: 5,677
Total Cats: 800
Overboost at 14psi did that? **** tune?
My stock 94 engine has seen 20psi a couple times, and my overboost protection is at 18psi, with the boost set around 15psi. From a gt2560, and a nice intercooler... Perhaps you just don't(didn't) have good enough supporting mods, and tune.
My stock 94 engine has seen 20psi a couple times, and my overboost protection is at 18psi, with the boost set around 15psi. From a gt2560, and a nice intercooler... Perhaps you just don't(didn't) have good enough supporting mods, and tune.
#8
Junior Member
Thread Starter
iTrader: (1)
Join Date: Aug 2011
Location: Queens, NYC
Posts: 150
Total Cats: 6
I actually think my intercooler is slightly too large but it helps keep the temps down very well.
The cooling system is good but not great. I have the Mtuned reroute kit and a 2" aluminum rad. The reason its not great is because I dont have good shrouding around the rad. That is a work in progress but the water temps seem to be stable even after a couple of back to back AX runs.
I am using RX8 440 injectors that were flow tested.
Anything else?
My power goals are moderate. 200rwhp.
The cooling system is good but not great. I have the Mtuned reroute kit and a 2" aluminum rad. The reason its not great is because I dont have good shrouding around the rad. That is a work in progress but the water temps seem to be stable even after a couple of back to back AX runs.
I am using RX8 440 injectors that were flow tested.
Anything else?
My power goals are moderate. 200rwhp.
#11
Elite Member
iTrader: (2)
Join Date: May 2007
Location: Cromwell, Connecticut
Posts: 2,605
Total Cats: 16
Mine popped w/ 120 miles on the clock (about 5k boosted) at the 200-225 rwhp range on a T25. It had a fairly safe tune too.
250 hp might be the average, but some do bend rods well before that.
250 hp might be the average, but some do bend rods well before that.
#14
Junior Member
Thread Starter
iTrader: (1)
Join Date: Aug 2011
Location: Queens, NYC
Posts: 150
Total Cats: 6
Can a bent rod be the cause of the knocking sound? The cylinder wall looked fine and the rod wasn't hitting anything. Valves seemed fine. Not sure what a spun bearing is supposed to look like.
#19
OR the slight bend put lateral torque on the piston, and it slanted in the cylinder, knocking off the cylinder walls... BUT, you said theres no wall damage.
im leaning more towards the first possibility