XJ4PLAY
NAXJA Member #1194
- Location
- The Pacific Northwest
Blaine B. said:
The sensor in the housing is for the ECU to control mixture and the electric fan etc.
The sensor in the motor near the fire wall IS for the guage.
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'96 XJ running too cold - even with Robert shaw tstat
- Thread starter 90Pioneer
- Start date
The sensor in the housing is for the ECU to control mixture and the electric fan etc.
The sensor in the motor near the fire wall IS for the guage.
Johnny V
NAXJA Forum User
- Location
- Jersey Shore
XJ4PLAY said:
Yes...just confirming the above also!
Also if hot air is coming out of the heater even with a low temp reading then my guess would be a bad gauge. If warmish-cool air was coming out of the heater with a low temp reading then your system IS running cool.
Also make sure you installed the proper temp sender for a gauge and not the idiot light sender. Sometimes what's in the box is not the correct item.
Don't take this personal...but did you install the thermostats correctly?
Happy New Year!
John V.
Sorry to bring up this old thread, but was the problem ever solved? I have the same problem after fitting my Taurus fan, large transmission cooler UNDER the radiator and a new radiator all at the same time. It now runs too cold unless parked, where like in this thread, it heats up to the right temperature to turn on the fans. So it is not the fans working too well as they are not on when it running too cold. The gauge must be right as reading correctly when the fans do come on. I am now also getting worse economy indicating that I am in open loop mode which also indicates the gauge is correct. I took out my thermostat ( Robert Shaw 195* ) which was still in there for before everything was changed, and boiled it in a sauce pan along with a thermometer and a brand new thermostat of the same I also had. Both open and closed at the 195*. Put the new one back in anyway and no difference as still runs at around 165*F or 77*C. The radiator shouldn't be affecting it either as when the thermostat is closed, the coolant is not circulating though it anyway? Only thing I am going to try after reading all this is a new cap as I swapped the one across from my old radiator as was only 2 years old but maybe not sealing as well now in a different radiator? Was working perfectly in the old radiator though.
Blaine B.
NAXJA Forum User
- Location
- Northwest Indiana
I'd put the cooler infront of the radiator, not related to your problem though.
Really happy with the cooler mounted under it as the auto doesn't have the delay anymore that it got when too hot. Not sure if you know but the Taurus Fan has been fitted vertically so the shroud hangs below the radiator and that space is then filled with the auto cooler. This draws air through it when on but it still gets cooling from a vent in the bumper when not as well as the stock in tank cooler.Blaine B. said:
- Location
- Bakersfield, CA
I can't figure mine out either. The stroker in the yellow XJ runs cold, around 165-175, nearly all the time. The only time I can get it hotter is if it's under a hard load, or if it's 100* outside with a decent load. So, it takes working the motor hard to get it to warm up to normal operating temps.
The buggy XJ is just the opposite, it runs at 210* no matter what I do, no matter what the outside temps, no matter what the load.
The buggy XJ is just the opposite, it runs at 210* no matter what I do, no matter what the outside temps, no matter what the load.
- Location
- MilkyWay Galaxy
Gojeep said:
Sounds like it may be running in an open loop, running too rich. O2 sensor problems will do that to the computer, keep it running rich, uses more gas, runs a lot colder. Thermostat could be stuck open with some trash, new higher capacity radiator will keep it running somewhat cooler inspite of the thermostat. Most thermostats have some water flow even when closed.
High a high capacity, non oem radiator, a really good new clutch, and mine ran at 140 in the winter at 35 F (with a 165 F thermostat), and 165 F in the summer, no A/C until I fixed the O2 sensor, cold loop problem. Now it runs hotter even with a 165 F thermostat. Gets up 185 to 200 in the 70-85 F ambient (no A/C) only after fixing the O2 sensor problem. It ran 165 F in 80 F weather before the O2 sensor replacement/wiring repairs.
Well I fitted a brand new cap today and made no difference. I also checked the temperatures with a high quality laser gun type reader and all the temps were reading correctly with fans turning on and off when they should and the gauge was correct also.
I have a theory, the Robert Shaw actually uses water flow to help open it rather than standard one which has to push against it. Now the temperature on mine rises correctly from cold until 195*. But as soon as the thermostat opens, it drops too far before it can close it again at 165*. The temp then rises again to 195* and repeats this cycle. So is it possible that my new higher flowing radiator which is a 2 row with wider tubes but has as many tubes as my old 3 row, ( along with my high flow Hesco pump that I have had for a while now ) is stopping the thermostat from closing? This would explain why it works perfectly in the saucepan on the stove without any pressure against it? So maybe just running a stock thermostat might fix it where the flow would help close it so long as it can open alright against the pressure?
I have a theory, the Robert Shaw actually uses water flow to help open it rather than standard one which has to push against it. Now the temperature on mine rises correctly from cold until 195*. But as soon as the thermostat opens, it drops too far before it can close it again at 165*. The temp then rises again to 195* and repeats this cycle. So is it possible that my new higher flowing radiator which is a 2 row with wider tubes but has as many tubes as my old 3 row, ( along with my high flow Hesco pump that I have had for a while now ) is stopping the thermostat from closing? This would explain why it works perfectly in the saucepan on the stove without any pressure against it? So maybe just running a stock thermostat might fix it where the flow would help close it so long as it can open alright against the pressure?
Blaine B.
NAXJA Forum User
- Location
- Northwest Indiana
Coolant temp sensor maybe - not letting the engine warm up? Test the resistance on it.
- Location
- Maurertown,Va.
Gojeep said:
I have a similar set-up ,in that I had a custom radiator built,thicker core and larger tubes.I first ran the stock T-stat,Flow-Kooler pump and summer temps would stay at 210* during normal (65 mph) driving.Switched to the RobertShaw 195* t-stat and the temp went down to 195* at normal speeds.Then winter came and with temps at 40*F or below the time to heat up was longer and the temp at normal speeds was lower.Switch to stoct t-stat and temps at normal speed is back to 210*.
There was a wide swing in the temp when the RS stat opened and it took about 1/2 hour at speed to remain constant.The stock stat will have a constant temp in about 15 min.
All temp are from an after-market Auto-Meter guage located in the stock location.
Now I wonder if by building a larger capicity radiator that the balance of water in the rad and water in the engine has changed and this causes the large fluctuation in temp changes until the system reaches a balance point ?
Again more questions than answers.
Wayne
Blaine B.
NAXJA Forum User
- Location
- Northwest Indiana
FYI my Stant SuperStant thermostat seems to be right on target with OEM and such...
I just have been shocked here that three different places I tried, none had a 195*F in stock and had to get one in. The cost ( nothing to do with having to get it in ) was $52 for one place and $66.50 for the other!!!
I think the dealer will be cheaper so will try them this morning.
I think the dealer will be cheaper so will try them this morning.
Drew_98xj
NAXJA Forum User
- Location
- West Jordan, Utah
mines a 98 she ran cold on cold days hot on hot days so i replaced the water pump, radiator, thermostat and hoses and she runs at 210 all tthe time now and warms up alot faster
Well I just pulled out the box where I had a thermostat that came with the Hesco water pump a few years ago but thought it was the wrong temperature and why it had not been used. But it turns out it does have the right temperature and is a 'normal' one I was trying to get. I remember they were going to supply a balanced thermostat, the same I have now, but they didn't have one the right temperature. So I must have asked them to just supply a standard one in the right temperature instead but didn't use it when I picked up the balanced ones in Seattle. So will try that one today.
Another thought is that increasing the pressure inside the block gives better heat transfer as stops the water boiling off the cylinder walls. This is one of the benefits of using the high flow water pump in the first place but others use restrictor plates. Cant think of where to put one that would increase only the block pressure but reduce the pressure at the thermostat at the same time?
Another thought is that increasing the pressure inside the block gives better heat transfer as stops the water boiling off the cylinder walls. This is one of the benefits of using the high flow water pump in the first place but others use restrictor plates. Cant think of where to put one that would increase only the block pressure but reduce the pressure at the thermostat at the same time?
On restrictor plates I found these ones but looks as it is used as a replacement for a thermostat only. http://www.amazon.com/Mr-Gasket-6126-Outlet-Restrictor/dp/B000BWAPIY
If I use one of these in the top hose it would increase the pressure inside the block but also around the thermostat as well. I have seen them placed before the water pump as well to slow flow though the radiator too but that would reduce pressure in the block which it not a good thing.
I just see how this goes I think with the standard thermostat.
If I use one of these in the top hose it would increase the pressure inside the block but also around the thermostat as well. I have seen them placed before the water pump as well to slow flow though the radiator too but that would reduce pressure in the block which it not a good thing.
I just see how this goes I think with the standard thermostat.
Last edited:
Fish'nCarz
NAXJA Forum User
- Location
- Victor, ID
Gojeep said:
I have put in two Robert Shaw 195 F thermostats and I believe that they don't close once opened until they get pretty cold. Mine warms up properly at start-up and then drops to about 170 or so, and doesn't start climbing until it gets around 140-ish. I just quit worrying about it since i have good heat and the engine hits operating temp from time to time. No condensation in the valve cover so I don't think I have a problem. FWIW.