Accelerated onto expressway then extreme misfiring...
EvoM Guru
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Joined: Mar 2006
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From: Tri-Cities, WA // Portland, OR
Who is tuning these cars? I can't help but wonder if det is the issue instead of non-det cylinder pressure.
There are a number in Puerto Rico as well.
We have had the engines we have first hand experience inspected and there are no signs of detonation upon teardown.
I can only speak to my case in particular. Mine was tuned with EcuTek (important here as at the time it was the only tuning solution that allowed for full logging) on a dynodynamics dyno and then touched up on the road afterwards. Knock retard was watched very closely with an understanding that it is not the same as the old knocksum from 8's and 9's, that is to say knock retard of 1 = 3 count knocksum.
When this failure occurred I was at a loss to explain it and could only conclude that the knock detection algorithm on the X was def to certain events, that is until I got a closer look at the pistons and head and could not find any evidence of anything other than foreign objects bouncing around the the cylinder, that is to say no det pitting on the pistons or head, no metal deposits on the plugs, just gouges from the piston chucks bouncing around in the bore.
I have no explanation as to why only some engines seem to be affected by this issue. maybee a quality control issue with mitsu or a bad "batch" of rings, or the ring filing robot just got lazy for a day
Thread Starter
Joined: Apr 2007
Posts: 434
Likes: 1
From: In the Middle of Everywhere
So I drove my car to AMS. They used a borescope in the suspect cylinder. The piston looks good. So if it was an object that caused this then it is out of the system. The spark plug was replaced since the insulator was cracked. Other than that everything seems ok. I will get into boost to test the turbo out a bit once I leave. Man I am relieved!!! Still want to know the cause but glad the engine is intact.
What cylinder #?
I've seen other Evo owners relieved too once they replaced the plug and it bridged again three weeks later. Once a piston starts to deteriorate, it gets worse over time.
Detonation can and will break the ceramic insulator as you have experienced, however we still believe ring damage to be the culprit.
I've seen other Evo owners relieved too once they replaced the plug and it bridged again three weeks later. Once a piston starts to deteriorate, it gets worse over time.
Detonation can and will break the ceramic insulator as you have experienced, however we still believe ring damage to be the culprit.
Yup, it starts with #4 and then the next cylinder to go is #1.
On another note, we just received a call from another Evom member sharing their blown 4b11t Evo MR experience on AEM methanol injection with us.
Although it was another 4b11t failure, we do not attribute it to ring end gap issues, but severe detonation as the wrist pin and rod was driven through the piston.
On another note, we just received a call from another Evom member sharing their blown 4b11t Evo MR experience on AEM methanol injection with us.
Although it was another 4b11t failure, we do not attribute it to ring end gap issues, but severe detonation as the wrist pin and rod was driven through the piston.
The piston is clearly not damaged according to the tech that actually looked inside the cylinder. You won't find any more information in here to support your claims TTP. I'd appreciate it if you don't scare the crap out of our customers for no reason.
For the record, I'd say that detonation can easily cause the porcelain to crack and cause all sorts of other issues, but I maintain that closing the plug gap with detonation is hearsay at this point.
For the record, I'd say that detonation can easily cause the porcelain to crack and cause all sorts of other issues, but I maintain that closing the plug gap with detonation is hearsay at this point.
Thread Starter
Joined: Apr 2007
Posts: 434
Likes: 1
From: In the Middle of Everywhere
My car seems ok. The difference between my car and the rest is I am only and HAVE only run a peak of 22psi and that is while tunedm. I respect you sharing your experiences as these scenarios are all good to know however I believe my situation is different.
Newbie
Joined: Apr 2008
Posts: 40
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From: nj
i advise not to use a Manual Boost Controller and let the ecu handel it
Originally Posted by WarmAndSCSI
And besides TTP, the piston material that is lost is not solid. It is molten during the combustion event that dislodges it because the boundary layer that usually protects the piston crown is lost. The temperature of combustion is WAY higher than the melting point of aluminum. That aluminum usually stays molten while it travels out the exhaust vales, through the turbine, and ends up coming out the tailpipe in little specs of aluminum dust once it solidifies again (it won't bond to the carbon-coated exhaust).
It's actually rare to see turbine damage during piston failures unless chunks of ring follow the piston material. Those same chunks of ring wreak havoc on the combustion chamber and plug, but the piston material just makes a molten mess everywhere.
It's actually rare to see turbine damage during piston failures unless chunks of ring follow the piston material. Those same chunks of ring wreak havoc on the combustion chamber and plug, but the piston material just makes a molten mess everywhere.
Last edited by TTP Engineering; May 12, 2009 at 12:16 PM.
The piston is clearly not damaged according to the tech that actually looked inside the cylinder. You won't find any more information in here to support your claims TTP. I'd appreciate it if you don't scare the crap out of our customers for no reason.
For the record, I'd say that detonation can easily cause the porcelain to crack and cause all sorts of other issues, but I maintain that closing the plug gap with detonation is hearsay at this point.
For the record, I'd say that detonation can easily cause the porcelain to crack and cause all sorts of other issues, but I maintain that closing the plug gap with detonation is hearsay at this point.
We are tired of hearing cases of 4b11t failures being put on the DL. Instead the forum should be sharing this insightful information as it occurs so that similar circumstances can bring to light design flaws in the engine that can be addressed by Mitsubishi.
The east coast is 3 hours ahead of the west coast. Its not surprising that the west coast is trailing behind in the information stream.
In reality you're 21 hours behind new developments when the west coast works on stuff and you've already gone to sleep.