First off, I'm new to these forums so if this post is in the incorrect spot, I do apologize.

My name's Justin. I drive a 2004 Evo VII GSR that has one or two mods done to it (I'll post the mod list at the end of the post). I've come into some pretty serious problems with the car, and I come here to the forums to try to figure out what the cause was.

Here's the story: I had a highway to myself one night so I was "getting on it" a bit. Mid-boost, all the sudden my windshield was covered with water and there was a smoke show coming from the engine bay. I pulled over quickly and popped the hood to find that the upper radiator hose disconnected itself. This caused coolant to shoot EVERYWHERE. I also noticed that the car developed a terribly rough idle which would continue at any lower speed. I limped it home, making sure it wasn't over heating. After some further diagnostics, I found the radiator cracked and coolant got into the spark plug area. I replaced the radiator, and cleaned the entire spark-plug area. I then went to turn it over. The idle was much better. But that's when I noticed it was shooting coolant out the exhaust. I shut her down, and checked the oil. Was milky as hell. So I know it's a shot head gasket, that's not the issue. What I want to hear some opinions about is what caused this. Given what happened, what series of events occurred to make something like this happen? My reason for asking is simple: I don't want it to happen again. What do you guys think? Note: The car has only 8,000 miles on the current build. That's what worries me.

Here is a list of the important mods:


AMS 2.3rr Stroker Motor
FP-Black Turbo
Shep Racing Stage 3 Transfer Case
Shep Racing Rear Diff.
AMS Fuel Rail
Injector Dynamics 2200CC Injectors
Head Games Head Complete Stage 3
Rev 3 Intake Manifold
JM Fabrications Custom-Made Intercooler Piping
Slowboy Racing FMIC
JM Fabrications Oil Catch Can
Stance Stage 3 Coilovers GR+3
Exedy Twin-Disc HD Clutch
Shep Racing Stage 3 Transmission
Busher Racing Double-Pumper Fuel Pump
APR Fuel Filter
DNP Exhaust Manifold
DC Motorsports 3" Down-Pipe
Tomie Titanium Cat-Back Exhaust System
AEM True Boost Gauge and Boost Controller
AEM Air/Fuel Gauge
Megan Racing Radiator
Spark-Tech Non-CDI COP’s


Any feedback is appreciated, thank you.

 

Possibly heatsoaked intercooler causing knock.

 

Could be the tune: knock = detonation = blown head gasket.

At any rate, it seems like the head lifted under boost and pressurized the coolant system. It could have been caused by an improper tune, a tune that's too aggressive and you got a bad tank of fuel (causing knock), or an improperly torqued head.

 

Agreed with these guys, the tune likely wasn't up to par and stressed the gasket. Once it went, you pressurized the cooling system and the weak point gave out. Who tuned it?

And I doubt the FMIC caused it. You shouldn't see that much variation in knock with a warm FMIC on the street, and certainly not see it climb enough to detonate a HG to death. Hell, I'm on the stocker still, and it's still fine on the dyno. His may be an SBR part, but do you really think they're still ****ing people after death?

 

I guess I'm confused by what you guys mean by "knock." The car idles okay, I imagine I would notice if there was a consistent knocking. Unless you mean there was a single knock when the head floated (possibly) and then it all went to hell.

As an extended piece of information, the car was tuned at Boostin Perfomance in IL but after some ignition troubles, the boost was turned down. I'm thinking maybe after turning down the boost it threw off the rest of things and thus resulted in this mess.

Well either way, it's being fixed and it will be retuned anyway. Thanks for the responses.

 

What fuel and boost level? It was definitely knock related. Even a perfect tune can't fix a poor quality fuel or a mechanical failure.

 

It's running E85 at 28-29psi.

 

Did AMS install the head onto the block? If not who did?

 

At a glance, it seems most likely that the head gasket seal was compromised, allowing combustion gases into the coolant system, resulting in cracked radiator and popped hose from the pressure. The compromised HG also permitted the over-pressurized coolant into the oil passages, which contaminated the oil system.

Why did this happen?

One noteworthy property of E85 and high octane fuels, there isn't necessarily a warning (knock) when ignition timing occurs before MBT. As such, alcohol fuels tend to grenade engines when the ignition timing becomes too far advanced, leaving no trace of recorded preignition (knock) in its wake. This makes tuning E85 not as straightforward as tuning pump gasoline.

In some cases, an ignition timing issue may not be a fault of the tune, but of a subsequent mechanical change that necessitated a revision in the ignition map. Even if you turned the boost down, that doesn't necessarily guarantee safety, as the timing could be off in the lesser load cells. In any case, when alcohol fuels are ignited too early, the HG is subjected the brunt of the pressure. In some cases, the HG holds, and the result is broken reciprocating parts. In others (like yours), the HG fails, which oftentimes saves the engine. If this was indeed the case, consider yourself fortunate.

I suggest you take the time to get things cleaned, purging the coolant and oil systems in the process. Before reassembly, replace all head studs and inspect the rotating assembly. Hopefully you don't have a bent rod. I would strongly urge some retuning time as well. Better safe than sorry.

 

Honto, being as the head is aftermarket, it was Boostin Perdormance that installed the head unit not AMS.

Ted B, that was very informative, thank you. I plan on deconstructing the entire top side as well as inspecting the connecting rod bearings to ensure any leaking coolant didn't affect that stuff. I know I'm screwed, I just hope I'm not totally screwed.

 

Also, what engine management are you using?

 

The car was tuned using the stock ECU unit.

 

Fine. The factory ECU is virtually unequalled when it comes to practive, efficient knock detection and protection. However, like I mentioned, when it comes to alcohol, one can grenade the engine without ever seeing knock. If I had to hedge a bet without seeing any more from where I sit, that's where I'd put my money.

 

I had a similar problem. The best conclusion I came up with, was that the head lifted and killed the head gasket. After talking to a few people they reccommended to torque the head bolts to more than ARP had suggested. After replacing the gasket and torquing the head to the new torque specs I have not had an issue since.

 

Sounds like aggressive tune or bad e85 to me. Both have the same end result unfortunately.