Vitzaa
NAXJA Forum User
- Location
- Los angeles
Hey guys!
Got another problem with my rig...
'01 xj, Russ's 87 octane 4.6 stroker (3k miles). Novac ax15, 4.88 gears, 35" tires. 5,800lbs (armor, RTT, toolbox and tools)
Been running hot since before the engine rebuild, still ran hot after rebuild. Flushed/back flushed the heater core a dozen times and got a ton of crud out. Figured radiator clogged up so threw in a new mishimoto rad. Still heating up so figured it might be the dual Cali cats (200k miles), replaced those as well and am still running hot.
Non highway temps are 210-220's
Highway temps 240-245 (2,500 rpm)
Coasting down the offramp drops me to 220
At idle, temps creep and hover around mid 220's
Ngk plugs, one step cooler
New fan clutch
New silicone hoses
New 180deg tstat
Flushed system and ran thermocure a week, got more junk out, nothing large
G05 coolant
Water pump is a flowkooler
Temps at radiator inlet are about 20 degrees hotter than radiator outlet while at idle and temp sensor showing 220
Electric fan works
Passenger side of head measured 190's at idle (forgot exact number.
Not really sure what to do from here...
Thinking of replacing the water pump as I've read the flowkooler can cause some cavitation at higher rpm, but it shouldn't be an issue at 2,500 right?
Run thermocure again in case there are blockages?
Hood vents?
Replace temp sensor on tstat housing?
Go two steps cooler than stock on the plugs?
I'm just kinda stumped. I know the hopped up motor and weight are a factor but I feel like it shouldn't be in the 240's...
Got another problem with my rig...

'01 xj, Russ's 87 octane 4.6 stroker (3k miles). Novac ax15, 4.88 gears, 35" tires. 5,800lbs (armor, RTT, toolbox and tools)
Been running hot since before the engine rebuild, still ran hot after rebuild. Flushed/back flushed the heater core a dozen times and got a ton of crud out. Figured radiator clogged up so threw in a new mishimoto rad. Still heating up so figured it might be the dual Cali cats (200k miles), replaced those as well and am still running hot.
Non highway temps are 210-220's
Highway temps 240-245 (2,500 rpm)
Coasting down the offramp drops me to 220
At idle, temps creep and hover around mid 220's
Ngk plugs, one step cooler
New fan clutch
New silicone hoses
New 180deg tstat
Flushed system and ran thermocure a week, got more junk out, nothing large
G05 coolant
Water pump is a flowkooler
Temps at radiator inlet are about 20 degrees hotter than radiator outlet while at idle and temp sensor showing 220
Electric fan works
Passenger side of head measured 190's at idle (forgot exact number.
Not really sure what to do from here...
Thinking of replacing the water pump as I've read the flowkooler can cause some cavitation at higher rpm, but it shouldn't be an issue at 2,500 right?
Run thermocure again in case there are blockages?
Hood vents?
Replace temp sensor on tstat housing?
Go two steps cooler than stock on the plugs?
I'm just kinda stumped. I know the hopped up motor and weight are a factor but I feel like it shouldn't be in the 240's...