captainsensible

Hi,

Firstly, will say HI from the UK

Secondly, I am hoping that the collective knowledge here will help restore my sanity (actually thats got some pretty wide scope but help with my Cherokee would be a good start!)

Ok, I bought a 1998 Cherokee before Christmas, its a 2.5TD Limited and I knew upon buying it that the heating system needed looking at.... temp gauge was lowish and no heat in cabin, so was thinking thermostat. Mechanic agreed so I booked it in to be done....

Then, catastrophe! We had a really cold weekend during which I didn't drive the jeep (hell, it was cold in there) but then on the Monday morning I set off in it to work... now, imagine my surprise when the temp gauge rose above where it had previously been... and rose, and rose and kept rising... many expletives went through my mind and then before finally then temp gauge dropped to zero and the check engine light came on.... I decided at that point, to turn around and get it to my mechanic...

At this point, the jeep was still running but very sluggishly - was thinking it was in limp mode, so I nursed it back to the mechanic (only 10 miles or so) and got there.

He took it in and we discussed what to do... the head gasket had not blown, but the radiator had cracked, presumably because of the cold. He was able to fix this with radweld stuff. He then set about replacing the thermostat (new one supplied by Jeep). This wasn't helped by the thermostat housing being welded to the bolts so he had to source another housing which took ages as it was over Christmas and New Year.

So, now, the thermostat has been replaced but the following problems remain:

1. The Check Engine light is still on and he has tried 4 different OBDII scanners to connect to the car and none of them can connect. I have done the 'key trick' and there are NO codes being displayed on the dash.

2. He has had the battery disconnected for a couple of days but the Check Engine light refuses to clear - now, as I understand it, he would not be able to connect to the OBDII if the light had been reset, until the car had been driven for a 'lengthy period' for it to relearn but the light has never reset and doesn't seem to want to.

3. The temp gauge now does not move off 0 at all since the new thermostat was put in. Combined with this, the heating fan control now does not work at all (previously it did). Its hard to say whether the heating in the car is any warmer than it was but the mechanic has attempted to flush as many of the hoses and the heater core as he can. The temp gauge definitely still works as it moves when doing the 'key trick' diagnostics

4. The radiator is not 100% leak free (I realise I need to get a new one) but, according to the mechanic, there doesn't seem to be much pressure in the cooling system.

Has anyone got any thoughts or suggestions as to what to look at next?

Sorry for the long first post!!!

captainsensible

Anyone?

Jakeshain

Ok, I don't know much about your type of engine but check the oil and see if there is a white residue in there. If no then you're good, next check to make sure both temp sensors are connected and replace the radiator. I don't know much about the 2.5 but it may be a closed loop coolant system which means if your have an air bubble in the system it won't work it's way out normally. Next, spay out the engine compartment so that there is nothing in there and allow it to dry, start it up and let her warm up. Once the tubes from the radiator is warm, squeeze them hard enough that you can feel the pressure, look for your next leaks. Sounds to me like you have a closed loop coolant system though.