I was trying to figure out why my rover overheats when i turn the a/c on on the freeway. i figured it was the radiator but i thought id try the thermostat first and there was no thermostat! so i put a failsafe from autozone in(probley stupid since a lr one is the same price) and now it overheats every time i try driving it. i tried to get all the bubbles out by taking the plug out of the radiator and pressure tank. had it idling for 30 mins and was fine. soon as i pulled out of my neighborhood my guage went up to half way and went down so i went home. yesterday i was stopped at a light and my guage went to about 10oclock and then went back down on its own before i started moving.

electric fans work, mechanical fan roars on startup, new pressure cap, fan is on right, belt routing is correct,

supposed to be a new rebuilt engine, new radiator, and new water pump less then a year ago. i dont believe it since the engine is knocking like it has a slipped liner :l

thanks for any help!

 

Fan clutch... Mine was very similar acting... The fan clutch worked fine for about 5 minutes then it lost all its coupling power... Took me awhile to identify it as the source... Since replacing it all has been fine even on the hottest of days... There is a chevy truck clutch that is bunches cheaper than the Land Rover one... You will have to ream the fan blade mounting holes a tad larger, but it's really easy to do...

 

2000 Chevy Express van 4.3 liter w/o AC clutch is what he speaks of. But also consider the following:

1. No thermostat meant PO had problems.

2. Fail safe will latch open and now you are back to stuck open stat. Replace with 180F stat (about $10). Jiggle device goes at 12:00 position to pass those gas bubbles. Bleed those out with the bung hole in the radiator elevated (put wheel up on curb, etc.)

3. Electric fans come on when AC turned on. In your driveway, turning on AC should suck plastic bag toward the grille, not blow it away. My PO wired replacements reverse polarity. Combined with a dead fan clutch, the main fan would almost stop at idle. Air flow was being subtracted by the electric fans blowing wrong way.

4. Get a scanner or Ultra Gauge to see the real coolant temp and know if you are making progress. The gauge is not accurate.

5. Radiator can be sludged up, and with higher load just can't keep up, even on freeway where fan clutch and fan are not the main airflow. Use an IR thermometer and measure on the fins, top to bottom, after truck warmed up fully. If lower fins are more than 10F cooler, can have sludge. It can build up row after row (horizontal rows, very good for holding stop leak compounds) and even make the center cold, so that air hitting the face of the fan clutch is too cool to make clutch re-engage. Rad is copper/brass, a small rad shop can unsolder side tank and rod it out (calcium) and hot tank it (citric acid), was $75 for me. New rad is $600-700, or aluminum one for $235. Don't forget space between rad and AC condenser, gets full of mud and trash.

 

i thought mine over heated with the a/c on till I realized i have a short, when i push the a/c button my temp gauge instantly goes all the way up, turn the a/c button off gauge instanly goes to normal

 

Clogged radiator.

The guy selling it prob meant to say it needed all of those things not that he replaced them.
Why would you sell a car after spending the money on a new engine?
If I ain't keeping it I ain't having the engine rebuilt.

 

im going to go buy an infrared temperature guage tonight and test the radiator. if its a huge difference between the top and the bottom ill pull the thermostat till i can get a land rover one and a new radiator. i kinda need it tomorrow thats why.

 

I was bidding on a super clean low mile 04 last month near me and it had new rad, fan clutch, coolant flushed,water pump, thermostat but overheated after a few miles of driving, guess they realized it needed head gaskets and didn't want to dump any more $ on it

 

gunsanroses91 -

You don't have to get a dealership Rover thermostat, it is the same as fits 300 plus GM models. Just get the alternative temp 180F one, not the fail safe.

 

oh cool thanks for the info! i got the gauge and the driver side was 10-15 degrees different and the passenger side was 30-40 degrees different. not sure what this means but i tried revving the engine a little while trying to bleed it again and i think a few more bubbles came out. then i went to the gas station and home without a blip!

im supposed to be using the gauge on the tanks on the side of the radiator right?

thanks everyone!

 

Nope. Slip off the removable part of the fan shroud. With engine off. Start at top of fin and read top then bottom in same vertical line. Would be normal to be different left to right tanks.