Bad headgasket? The big C? Might be DT time....

[6.9poweredscout]

1991 7.3 banks sidewinder, 90cc pump, 80k on engine. Has hit 18 psi boost, egts upwards of around 1250 never longer than a few seconds. Was going to Lancaster to deliver a truck, was about 2 hours in, passed all the hills where the egts and boost was high so I wasn't watching the gauges as much. Running on the flat about 70 I noticed the temp was spiked past 240. Pulled over, let cool for a bit, got the cap off and low coolant. Four gallons worth I was mobile again, stopping to check constantly. There's steady bubbles from the puke tank, temp hasn't gone above 20 the rest of the trip (about 4 hours from Lancaster, getting parts then home). Heading back unloaded I was easy on it and it didn't use a drop of coolant. At 190 engine off the system will hold 16 psi for about 45 minutes, then creep to 11 and didn't move. I let it idle an hour and it never got above 190 but constant bubbles from the rad. no oil in coolant, vice versa, no tailpipe smoke. thinking of pulling gps and seeing if one is steam cleaned.

here's the video.... thoughts?

https://www.facebook.com/video.php?v=851534634857093&l=1753006386839509658

 

[lotzagoodstuff]

Just wondering: if you're block was damaged by cavitated, wouldn't you see some "milkshake" effect in the oil? 18 psi sounds pretty high for a non-studded IDI, I'm guessing you just pushed out a head gasket, and I think checking the GPs is a sound starting point.

Good luck, keep all my fingers crossed it's just a head gasket.

 

[david85]

+1 on the head gasket