I did the inline thermo mod about a year ago. When I put in a 160 or a 180 stat it will overheat. So I have been running without the stat for about a year.

I even put in the grey thermostat from land rover with new hoses and still over heats. So I put the inline mod back in with no stat with straight water. no coolant.

I replaced the heads about a year ago and that is when it started over heating.

Also put in a new water pump and the hayden fan clutch at the same time I did the heads. and a new radiator.

Any ideas on why it would over heat with the inline mod w/thermostat or without the mod with the grey land rover thermostat?

It runs at 70c without stat driving 80 miles on highway to work and the same on the way home.

 

So it runs 70c with not thermostat which is 158f(needs to be 160f to go into closed loop fueling). What is the temp with 180 thermostat? Sounds like there is air in the system. Took me several days of bleeding each afternoon after engine cooled off to get it ll out. Now it is pretty steady at 181-185.(with inline setup). Charlie and I have been discussing the inline setup and 1 thing I have a problem with is, I think the inline thermostat should be as close as possible to the engine. Charlie switched position of the bleeder and the thermostat, but I have not heard if it has made a difference. I am researching the feasibility of cutting the outlet pipe coming out of the manifold and installing the thermostat as close as possible then routing pipe straight to the radiator. When i start up, the temp can spike at over 200 before the thermostat opens, then drops down to 178, then back up to 196, then back down, and finally settles to 181-185. If the thermostat was at the engine manifold, it would open much sooner and not spike.

 

it would reach 220 when I had the 160 or 180 stat in. it would stay at 194 when I was driving, but when I stopped at the light it will hit over 200 within a min. this was a test drive after I put the stat in. when I got back to the house, it was at 225f, it had boiled over. thought I blew my new headgaskets but thankfully I didn't. Did the same thing when I tried the grey stat from LR. so I just put the inline back in with no stat. I thought I had got all of the air out and also bypassed the heater core. the heater core is hooked backup now since it got a little cold here in south tx. had heat, but not much with out the stat.

was also thinking I got a bunk water pump. it was the cheapo 40$ one off ebay, new.

 

Are you sure that the spring side of your thermostat faces the engine?

I had a similar experience but it was air in the system.

In fact this week I messed with my hoses to make the thermostat closer to the engine and also make it easier to bleed. Exhibit A:



Easier to bleed:

 

I did put the spring towards engine. then I bought a high flow 160 with no luck. Hoping to get it fixed so I can run with a thermostat again.

 

Then it has to be air or, as you said, a funky water pump.

I get the cheap water pumps. They've never failed. The group wisdom here is the buy the expensive ones with brass impellers.

 

I am going to work on it again this weekend. installing the oil breather filters and thought I would flush the system and try again with a thermostat. maybe I had an air pocket. I do have the inline sensor mount for the hoses. just need to get a bleeder screw for it.

 

Oh snap I just saw this. After I posted my Frankencooler pictures.

 

No problem Charlie, just trying to help.

 

Metal I would think that the air would work its way out pretty quickly. After I did my inline mod I filled from the expansion tank, setting it on the battery tray, until the bubbles stopped, then closed the little valve. I also tried filling it on both sides of the thermostat housing while holding the ends up. Both ways seemed to get most of the air out, but the latter was QUITE messy.

Also, I am a very recent convert to the drill a hole in the thermostat club. It really does make a difference. Make sure the hole is at the highest point. After I made the mods pictured I actually had to siphon some antifreeze out of the expansion tank whereas before I would always overfill it to make room for air.

When I first did the inline mod I did test my thermostat on the stove. You might try that. Just to be sure.