If it smells like fuel, it could likely be a head gasket.

The other thing is the use of the orange coolant (Dexcool I think). Did you completely drain your system before adding it? I know that if you mix the orange coolant with standard antifreeze it can cause issues. They combine and turn into a sort of gel substance that can block flow and ruin your cooling system and possibly your motor.

 

Theres a sniffer you can buy a Napa

 

Yeah, I drained the entire system before switching the coolant..

 

On a stock setup with just pump, I'd say 6 deg at peak is a lot off timing. Whats your cam/turbo/fuel setup? Any chance of seeing AFRs?

MB

 

When 4g63's blow headgaskets they pressurize the cooling system and water pissed out your overflow. I've ever mixed gas or oil into my coolant and I've blown more HG's than I care to mention.

Your log is much too short and your not getting enough data points. Try doing a 4th gear pull and reducing the amount of variables your logging.

 

It really depends on where the gasket is damaged, doesn't it?

 

The *typical* failure on a 4g63 is what I'm talking. If you notice the cylinders are surrounded by cooling passages. The oil port is outside of this way on the side of the block. Typically the head lifts and the cooling passages get pressurized with combustion gasses.

http://youtube.com/watch?v=OB3yxIo2usM

At the end of this video at the 4:10 mark you'll see the carbon deposits on the head where the exhaust gasses were traveling to the cooling passage. I drove about 8000 miles like this and it would use about a gallon a week and a gallon at the track.

Its nearly impossible on the 4g63 to mix oil with coolant and not be pressurizing the cooling system.

 

Yeah, I am going to be out this weekend trying some more logs. Honestly, the reason the logs are so short is because I can't get the motor to go past where I am having the serious knock. I am spending time detuning it right now, making it not so high strung and will see what happens this weekend.

I think I need to try to log the top clutch switch as well, just to see if anything funny is happening there.

I am really worried about this whole coolant thing, but not super worried. I have no cams, no internal work, all of it is bolt on stuff. I have almost everything I need now, with the exception of the belt pulley and idler bearings. Once I pick those up, I will be tearing apart the motor to put everything in. Once it's done, it will be one nicely built motor. I guess that will be the time I find out exactly what is going on.

Burgers, I have the car pretty much maxed out as far as I can take it, and it's a really aggressive tune. The car is really lean during spool (Never gave me a problem until now), and tapers to low 12's very high 11's by redline. It's run on straight pump 93. The fuel is PTE 680's, Perrin fuel rail and FPR. MBC too.

 

Hey all...

Just to put closure to this, I think I found out what was wrong with at least the tune.. It was a couple of things.

1. The weather suddenly got pretty cold here, thus making the air more dense, and I had the car running pretty lean prior in the hotter weather. With the air getting more dense, the tune became leaner.

2. The fuel mileage mods. Since I rescaled my maps (awhile ago), and was playing with making the car run in open loop, there was a section of my fuel map from roughly 0 to 80/100 that was never really touched because of "closed" loop controlling the fuel during this section of the maps. When I forced the car into open loop, it was running in these previously untouched sections, and made the car want to run lean in the spool up areas, thus causing knock early on in the pull, and the car wasn't able to sustain itself throughout the pull. I was spending so much time working on the mileage mods that with the combo of the weather getting colder, and pulling in open loop mode earlier, it lead to some heafty knock numbers.

Blah, I guess sometimes I get so focused on fixing one thing, that I forget about others and lose sight of the trees in the forest.