So I was an idiot and let people talk me into racing this built fox body 5.0 mustang shortly after I cranked the boost back up 18 psi (was about to go to 20-22 psi) on a new fuel map I started after I significantly changed my timing.

I had not had time to properly tune. We raced twice, back to back (yes the story just got stupider). I did walk on him both times, but both runs I was hitting rpm ranges that I've only guessed at the tuning.

My timing is about 18* for the most part at 18 psi, my EGT's hit 1675*F according to the peak and hold on the Zeitronix display. Looking at the MS datalog, AFR was about 13.0 at the most critical points. I leaned out.

Ever since I start to over heat, when my coolant temp hits 200* (I have a 180* thermostat btw) I begin to push boiling coolant out of the reservoir.

Compression test shows 170 170 170 ~163

Leak down test on all cylinders checks out except for 4. It *slowly* raises the coolant level looking at it with the radiator cap off, until after a while a small air pocket will seep through the jiggle valve in the thermostat.

I'm planning time, and finishing unpacking my garage so I can tear it down. I'm just wondering what the most likely scenario would be, a cracked head, a blown MLS headgasket (no fluid interchange going on), or a warped head (despite me using ARP head studs).

I can drive the car non-boosted for about 30 minutes, or boosting for about 5 before it pushes coolant out, it's slight.

Anyone else have anything similar to this happen to them?

Edit: This is one of the first times I'm actually glad something happened, for me to have a reason to tear down. I'm hoping that I'm not going to have to replace the head, so that I will have some money to throw some cams, and over sized valves in since they are long due.

Its really hard to say but I would count on at least a blown head gasket and warped head. Pray for no cracks.

Terry

Just be careful man, read my thread I made, I think you might be having the start of what I think happened to my #1. I never did a leak down but I was losing coolant, bubbling in the overflow and then finally melted piston.
Im calling cause of death on mine, a fried headgasket. Everything still seems straight and true with a machinists straight edge.

Good luck
DJ

Thanks for the input guys. DJ I've actually been watching your thread. It's ironic we both go down at the same time. The only difference between your symptoms and mine is that I have acceptable compression in the cylinder. Also, from the looks of things I don't seem to be pulling any coolant into the combustion chamber, just pushing it.

Most likely just the headgasket. Mine did the same thing once, just pushed a little coolant. The head was fine, I had a quick resurface done to make sure it was straight and put a new gasket down and it was fine. It didn't even blow when the last motor went.

That's awesome to hear...

He's at work right now, but I'm sure he'll be glad to read that :thumbsup


I'm forced to help wrench on his car only until I get my replacement lol

I had the same issue with a Cometic HG and replaced it with a Felpro. Everything seems to be holding tight.

Here is the thread:


http://forums.2gnt.com/dcboard.php?az=show_mesg&forum=4&topic_id=89338&mesg_id=89338&listing_type=search

OEM MLS is the way to go for sure...Joel just has a hard time believing something like this could happen considering it's a MLS headgasket and an aluminum head... :shrug

I just need to quit contemplating and tear it down already :). Just waiting for my first day off (Tuesday) in a while to get it done. Work + School + Finals has been eating my fun time.

I'll let you guys know what I find.

Originally posted by WickedESi
I just need to quit contemplating and tear it down already :). Just waiting for my first day off (Tuesday) in a while to get it done. Work + School + Finals has been eating my fun time. I'll let you guys know what I find.

Tuesday is poker night at Hooters remember! We can start the teardown right after class, but we're not missing it again this week lol.

Originally posted by WickedESi
I just need to quit contemplating and tear it down already :). Just waiting for my first day off (Tuesday) in a while to get it done. Work + School + Finals has been eating my fun time. I'll let you guys know what I find.

Do you live in Orlando? Xmasta19 seems to talk like you are in Central Florida.

Originally posted by mreigle

Originally posted by WickedESi I just need to quit contemplating and tear it down already :). Just waiting for my first day off (Tuesday) in a while to get it done. Work + School + Finals has been eating my fun time. I'll let you guys know what I find.

Do you live in Orlando? Xmasta19 seems to talk like you are in Central Florida.

Yeah lol...we go to UTI together :thumbsup

Yay! I got it tore down and there are some defined carbon marks on the head gasket (and slightly on the block) leading to a water jacket. At that same spot on the head gasket the layers are kind of separated all funky. I thoroughly checked for cracks, no sign of any. This means I can afford some upgrades while the head is in the machine shop :).

Ohhh snap!!!


...built head time :thumbsup