hadi820

My 89 renix was over heating when i first drove it home. when i parked it i noticed a big puddle of antifreeze under the passenger side.
here is what has been replaced so far.

- checked coolant bottle for cracks (its good)
- replaced original cap with volvo (green cap)
- had the system flushed
when getting emissions done it failed ( dude swore it was the cat so he replaced it, it still failed and overheated )

when we put our hand on the Rad, it was pretty cold.
- so he replaced the rad with a "new" used one
- replaced the thermostat.

still overheating. the only thing now is it doesnt have a fan shroud. I know it makes a difference but ive had 4 xjs and 3 of them did not have fan shroud.
any input?

cruiser54

Water pump fins rusted off? How bad was the old radiator?

I don't like the "used" radiator idea.

hadi820

I havent been working on it, this mechanic i bought my first XJ from is. he said the radiator is like new it was on his renix for a year, took it off along with all newer components and scrapped it.

I haven't seen the water pump.
I should have done the work myself but since it was already there and I needed it to pass emissions i let him work on it. Stupid mistake but I will get it back in the next couple of days and I will try to check out the water pump.

hadi820

Also the water that was in it originally was brown and it had particles in it.

88jee

With everything that you have replaced are you still leaking coolant?

Three%

My XJ has been overheating, I need to replace my water pump. Bearings are feeling loose and it also leaks.

hadi820

So here is an update. the mechanic said he replaced the radiator, t-stat, and burped the system.
and he said it was still over heating.

today i went to pick it up, he said he added a shroud and it doesn't overheat anymore. kind of suspicious.
drove it home and temp stayed around 190:
after testing if for about 30 minutes of city driving it stay that way. I was at a red light looking at the light waiting for it to changed. when i looked back at the gauge, it had spiked up past the 260 mark. and slowly went down to 240 and the spiked down to 190...
so I got suspicious feeling , is there anyway the mechanic could have rigged the gauge to make it look like it doesnt over heat.

the fluctuation would happen when i am stopped ...

when i got home it was idling at 210:


when I turned it off, it climbed up to 250ish:


and when i turned the electrics on it went back down to 210,


what do you guys think, could it be the temp sensor, could the mechanic have scammed me ?

also when is the fan supposed to come on. it wasn't on when i was at 205.

cooling system looked clean and wasnt leaking coolant, and the coolant was flowing from what it saw.

rackem

when it starts to overheat, turn your heater on full blast.

if it drops you will know that your thermostat is sticking.

if it doesnt you have another issue somewhere.

hadi820

not sure if its overheating or not. when its running the gauge stays around 200. but when i turn it off it went up.

when its running at 200 i turn the heat on full blast and it drops 10-20 degrees.

rackem

when motors turn off they do heat soak which does cause an underhood temperature to increase. so that could be what your seeing.

with the heat on blast causing change i would still be weary about the thermostat

my89xj

What he said. Check the water pump to, just replaced the one in my friends and the fins were completely rusted off.

hadi820

That is my next move, maybe i will have time next weekend.

but water is flowing through freely, and the thermostat is new, I just want to make sure that its not a gauge issue where i think everything is fine at 190-200 and its really at 260 or something crazy.

Pelican

When you turn the heater on, you are adding additional cooling fins to the system and the temp drops. This does not necessarily reflect on the condition of the thermostat which may or may not be defective, even if new.

You can fret and guess at gauge accuracy but the only way to tell what the system temperature actually is is to use an independent thermometer, the most efficient being an infrared unit.

I'm not sure about the Renix but the E-fan on later models comes on ~218*.

cruiser54

I agree. And REnix e-fan does indeed come on about 218.

freegdr

Did he replace the radiator ?