So these last few weeks have been nothing but a headache for me and I cant figure out what the issue is with my car. The other day I went to do a 2nd gear pull. As I was building boost I heard a loud bang and the car instantly lost power but didnt shut off. I popped the hood and noticed coolant everywhere. After some observation I found that the coolant hose going to the back of the t-stat housing had popped off. I put it back on and took it to work the next day to check everything out. Once on the hoist I noticed coolant leaking out of the timing cover meaning my water pump was most likely shot. I replaced the waterpump and drove the car for a few days. Did a few pulls without a problem but noticed some misfiring here and there. Yesterday I went to do a 3rd gear pull. As boost was building I noticed a nasty misfire and another bang, followed by smoke and coolant on the windshield. Looked under the hood and noticed a freeze plug shot out of the block. Took it to work and put it on the hoist again and Voilaaaa more coolant pissing out of the timing cover. Now I dont know what to do. The new waterpump has maybe 30 miles on it and wasnt cheap here in Canada. My first thought was the head could be lifting but thought its unlikely because it has arp headstuds. (BTW motor is built running about 30 psi on a 3586). Im going to do a compression and leak down test this week to see if maybe its a bad headgasket. Im also thinking about retorquing the head bolts althought the motor has about 10k miles on it and shouldnt need retourquing?? Is it possible for a nasty misfire to kill a waterpump? Im out of ideas now, any suggestions would be greatly appreciated.

 

sounds like the HG is leaking to me. i see it all the time on the ford turbo diesels i work on, they dont blow off hoses they blow coolant out of the res or crack it in half.
what i do in the situation at work is put a fuel press gauge inline with one of the small coolant hoses going to the rad. i check to see what the cooling sys press is getting up to with the truck under a load. if it goes higher than 15psi youve found you prob. hopee this helps.

 

The head DEFINITELY is lifting and pressurizing the cooling system.

 

So in this case should I try retourquing the head?

 

if you didnt already ruin the gasket -- tq'ing it might work.

 

So I did a leakdown test tonight. The numbers came out as follows; cylinder 1 - 22%, Cylinder 2- 16%, Cylinder 3- 8%, Cylinder 4- 8%. obviously there is an issue with cylinders 1 and 2. The weird part is that the car seems to run fine when cruising with no visible smoke or anything. I do have a nasty misfire under boost. Should I assume this is a problem with the head gasket and just replace it to be safe? Or is it possible that there is some sort of other issue? I also forgot to mention that the head is o-ringed.

 

when you do this, before you replace the HG make sure you check the head face and the block deck for warping.

 

All cylinders are bad. A leak down of more then 8% in a performance application is a problem.

Your hg, valves or rings are shot.

Do a compression test followed by a wet test to determine if rings are bad.

 

what are you torquing the head to? mine started lifting during tuning so we had to torque them to 105 and that fixed it

 

Im not too sure what the head was torqued to. It was built by the previous owner/shop. A leak down of 8% should be fine the gauge probably isnt 100% accurate. Im guessing the head gasket let go between cylinder 1 and 2. Im going to go ahead and take the head off tomorow and see what everything looks like aswell as bring the head to a shop to get it checked out. Going to put in another oem head gasket and torque the head, heat cycle and then torque it again and see what happens!

 

I had this same issue. Its your head gasket. I didnt think it could be as the car only had 1k miles on new motor. Replace the head gasket and get the head checked out buy a machine shop to make sure it is still flat surface and not warped. Make sure when you replace the head gasket that you take your time and do it right. I suggest a good coating of copper gasket spray and dont touch any sealing area of the head gasket!

 

definitely head gasket. speaking from experience, your car likely has too much timing. You can just keep replacing the head gaskets but eventually you will bend a rod if you don't fix the tune.

 

i would torque them to 90-100 because what arp tells you to torque to is not enough.

 

i would have done a compression test followed by a wet test to insure your suspicion is correct.

 

I warped my head when I overheated it on a hill climb and had the same issues (misfires under load), coolant spraying. 33psi + 2 miles going full throttle up hill = unhappy engine. I figured that 27psi was the sweet spot. (around 430-450whp).

Had the head milled down and put a new OEM headgasket with no sealants 85-90ft-lb on regular arp studs and haven't had issues since. Tried reusing my previous studs and they started stretching, so had to replace.