Hello, everyone!

I'm a fairly new member to the LR community and this forum. So far it's been a bumpy ride.

I tested positive for a very slight compression leak during idle in cylinder 4 awhile back when I went to get a check engine light looked at. I had just purchased it from a private party so I didn't want to dump another 1,500 on getting the cylinder swapped out just yet. Driving home my temp gauged spiked while I was going up a grade; I didn't lose power, the engine did not run rough, I was not puking white smoke. It just get real hot, real fast. I pulled off for 5 minutes, started her up, and finished driving up the grade without it overheating. Just as I was getting closer to home the gauge started rising, so I turned on the heater and that dropped it back down to normal.

I've been checking my coolant levels daily and they're normal. I've been taking her out on short drives and the gauge will fluctuate from normal to nearly red, unless I turn on the heat to bring the needle down.

Again, I'm not losing power, the engine runs smooth and sounds fine, and there's no white smoke coming out of anywhere. There is some occasional knocking coming from the right side of the block after I kill the engine, which leads me to think this is whole thing is due to that bad #4 cylinder? I will be popping off the thermostat tomorrow and checking the water pump, but I doubt my luck will be that good.

I have been looking through the forums but I couldn't find anything that quite fits my situation, with the lack of any other symptoms besides my Disco just plain running hot. The check engine light even went out on its own.

Any help/tips are appreciated.

 

How much oil is on the dipstick. A knocking and overheat could be a bad oil pump or clogged sending unit or just low on oil albeit not good news either way

 

Sounds like the cooling fan clutch is shot, spin the fan by hand see if there is resistance

 

I'd check fan clutch, too. Mine was doing that, put a HD clutch on and no problems since no matter how hot it is outside.

 

Might as well do a complete cooling system overhaul, if you are opening it up

1) 180 t stat- $20 ish
2) Have radiator rodded out- $70-$100 ish
3) Fan Clutch- $55-$75 ish
4) Maybe a new water pump based on inspection

My opinion

 

Thanks, all. I sincerely appreciate any input.

Fan seems to be fine, giving me good resistance. Oil level and color is normal. Water pump seems to be operating normally I still need to get around to popping off the t-stat so I'm holding on to hope that's going to be all she needs.

Again, I appreciate any and all input. Thanks, all.

 

Spring goes towards the block, small hole with toggle fitting at 12 o'clock.

Good luck

 

I ended up going through all that, ended up replacing rad with a $200 aftermarket one. It's been a year now and it runs cool as ice.

 

The radiator is actually brand new, had the old one replaced.

Just tested the t-stat and it's opening properly.

 

exhaust gasses in cooling system?
air in system?