Probelms with new XJ.

Today i picked up another XJ. its a 95 with 4.0 automatic. when i was driving the highway i came into traffic and the temp went up to around 240 but when i started to move it dropped rather quickly. i drove it around locally for a bit today and the temp kept going up to 240. every time i went to start it it cranked slower and slower. finally when i took it out again to night i tried to start it when i i came back and the starter cranked super slow until it stopped dead. anyone know what the starter issue could be? bad starter? how about the temp? is that normal? thanks in advance

let it cool down and check starter again... probably heat soaked and will crank once cooled. have you checked the electrical system yet? if battery was fully charged when you picked it up and drove it all day with a bad alternator it would be slowing more and more all day... as far as getting hot goes there are a million threads on here about how to diagnose the problem from start to finish. good luck.

drove it all night and lights didnt dim at all. charges at 13-14. people said alternator was replaced few weeks ago. if the starter dies when it gets to hot does it mean its time to replace?

My first thought is that It shouldn't be runnng that warm; and secondly, the starter could be heating up on one side of the windings causing it not to turn over when it hot, but the way that you describe it tells me it's a bad charge...

Try it when it's cold and charged up. If it starts, run it until it's hot and try to start it again. If it acts the same way as described and the charge is still up then the starter is probably bad.....

Running at that temp is a problem in itself though.

yeah. im gonna try replacing the clutch fan. because at idle it heats up but when driving its under 210. the heat may have killed the starter. i made a long drive home with the jeep today (about hour in stop and go traffic) i think the heat may have killed the starter. im gonna replace the fan tomorrow to try and fix the cooling problem. hopefully its starts so i can determine wether the starter is bad or not.

so did she start today?

do simple routine maintenance before you spend money on the fan. change the tstat, garden hose in the head and the heater core, etc

no start. pulled the starter and had it tested. turned out it was bad. i guess the heat killed it. routine maintenance has been done, water pump, flush, 165 thermostat. did the clutch fan for 35 bucks, no biggy. a friend tested the radiator with some kind of temperature sensing gun. by using that we found out that part of the radiator was clogged up. purchased a new rad today so that will hopefully go in on sunday.

put the right t stat back in as well... thats been covered a million times about the water not staying in the radiator long enough to cool blah blah blah but it works.... thats why its designed that way, the xj is one cooling system you don't want to stray too far from stock on. at least that's what i've found....

well the funny thing is it run cooler with the 165* than the stock 195*

thats because blockage in the radiator is doing the thermostat's job

the makes no sense. the blockage is making it run hotter. i replaced the radiator. now its running at a steady 205-210 in traffic and a lil lower when accelerating.

with the right t stat it should run around 195-200 if your gauge is acurrate and never move unless really hot day, a/c sometimes or a new problem arrises... do what you want but i bet you two donuts you will have a noticable difference with the 195. just my opinion though do what you want.

ill try the 195 in a few days.ill let u know

Blockage would make it run hotter at a light when the blockage was limiting the necessary flow rate. But it would make it run cooler when the blockage was matching the necessary flow rate.

The tstat is not an on/off switch but instead maintains a slight opening according to the coolant temperature (however it can open and close dramatically when temperatures shift suddenly). With a stock 195 tstat it will start to open around 180 and be fully open around 220. That is when hot coolant will leave the engine and go to the radiator, and when colder coolant from the radiator will enter the engine. If the tstat opens quickly because of a spike then you can see the coolant temperature (at the housing) drop very quickly as the hot engine fluids are replaced with cold radiator fluids.

With a blockage in the radiator and a too-low tstat, all of the flow will be controlled by the blockage chokepoint. The tstat will take itself out of the equation early on and the blockage will control the flow.

FWIW the biggest problem with a lower tstat on a working system is that it takes a lot longer for the coolant to reach operating temperatures and this causes the ECM to richen the air-fuel mixture to increase engine temperature

I always thought that running too lean increased engine temp and running rich decreased it. Thats why lean melts valves and provides a white plug and burns pistions while rich causes carbon build up.

But I agree that he should run a 195 for better gas mileage, less gas getting in to oil, and less carbon build up. In Jersey, I suspect, he can also use the heater in winter.

yeah running lean will increase combustion temps but the computer runs rich to increase exhaust temperature (post-ignition combustion) which works to heat up the cat converter

you'd think the computer would do something different for low coolant temperature but the FSM says it goes rich

put a stock thermostat back in and the temperature is still reading the same

I'm gonna guess blockage is messing you up then

blockage where? had the cooling system flushed. replaced EVERYTHING. its not running hot but still the same as with the 165