jjz28

On nowadays vehicles, it not like the old days. you have to have a t-stat. Back in the day you could take it out during the summer and put back in the winter. Now the radiators are smaller and engines dont hold as much water and the water has no time to cool in the radiator so you will overheat. Plus with the coolant temp sensors, your car needs to run a certain temp to run right.

djb383

Don't know about OBD-I systems but that's NOT true for OBD-II. Any scan tool, when plugged into the ALDL port under the dash, will show the system entering "closed loop" within seconds of cold engine start. Closed loop is entered when the O2 sensor(s) reaches operating temp which is well before the engine coolant reaches operating temp. Even in "open loop", computer controlled EFI engines run way leaner than carbed engines did/do.

kemjeep

OK you guys heres the skinny bought 92 xj in 01 with 98k on it tranny fluid dirty changed it and had it sucked out 11 gts with filter change problem #2 started running hot near 240 electric fan turned on flushed radiator with prestone didnt work had my mechanic change radiator and t-stat was told didnt have one #3 at 45 mph with torgue converter locked experienced small surging but noticable used many brands of injecter cleaner no help took to Alles jeep explained problem had engine decarbonized fixed was told this happened by previous owner running without t-stat I dont know how long it ran this way winter or summer thats why I made statement I guess in 20 20 I should posted this in the first place AMEN

UserID6095

Maybe its me, Im on hour ten at work, but I have no clue what you said.

djb383

ROTF,LMAO

mcssls

with no thermostat you can get the coolant to flow too fast. Then it doesn't stay on the cylinder walls long enough to absorb heat correctly, so on your gauge all will look good but, the cylinder walls don't cool down, oil cokes up in the rings losing its lube ability and the cylinders get scored greatly shortening the engine life.

I am running ff dynamics triple threat extreme fans with a $90 high flow water pump from summit and stock thermostat and water wetter. I can stay at 210 whenever moving, even 5 mph sitting in traffic I can still pass 210 but not close to the danger zone. Next spring I'm putting in a 2 core or an aluminum rad.

djb383

4th paragraph....."A common misconception............"

http://www.stewartcomponents.com/tec...ech_Tips_3.htm

kemjeep

To trs80 I was explaning my statement concerning engine running in open loop situation it was because radiator blocked before I bought it they took out t-stat and the engine had carbon build on pistons which caused the surging my intent was state dont take the t-stat out

djb383

A 2000 model is OBD-II and switches from "open loop" to "closed loop" within seconds of engine start-up. The signal from the O2 sensor closes the loop, not the coolant temp. Any engine with 98K miles is going to have carbon deposits, that's just part of the internal combustion process. I don't see how carbon deposits can cause surging.

Lestatic

I have an 01 xj, my radiator broke in half I went ahead and replaced it as well as the water pump and thermostat housing and put in a thermostat since it didn't have one when I took off the housing. I got everything working and after 3days of driving it from home to work back and forth, I drove it bout 3miles to the store I saw water coming down my axle I checked it out and it was coming out of my reserve tank, the old radiator as well as the inner block was full of rust and had a load of mineral build up what Chemical can I use to flush out the block without breaking it or messing up the new parts I put in! As well can I run my jeep without the thermostat?
Also when I start my jeep it does take a few more seconds longer, b4 I had replaced everything I had no starting or drag issue, as well I feel a rough drag on my driving!