nathan Posted September 21, 2007 Report Share Posted September 21, 2007 I need some help here. I am trying to isolate an overheating issue with my TB. I have a new water pump, new fan clutch, (installed and working for a month) 2 new thermostats yesterday and today and the damn thing still won't cool off. I have had the system flushed, it holds pressure and doesn't appear to have any air left in the lines as I have tried once with the repairs and then had a guy up by Worthington Hills look at it today and he too came to the same conclusion. Symptoms are as follows, it will go up to operating temperature fairly slowly and then continue to overheat. I have no heat coming out through the heater core (I suspected air, but it does not appear to be the case), the lower hose off the radiator is only 150ish with IR temp and the top hose is 240ish. It sounds like maybe a blockage in the radiator, but it flushed out okay so it has me stumped. Quote Link to comment Share on other sites More sharing options...
Vander Posted September 21, 2007 Report Share Posted September 21, 2007 I have the exact same problems going on in a BMW 3 series. The clutch fan was replaced then broke. It broke because it overheated due to the radiator. I would say you need a new radiator, and possibly a new fan clutch. Is it an SS? Quote Link to comment Share on other sites More sharing options...
RUTAN TA1647545492 Posted September 21, 2007 Report Share Posted September 21, 2007 Have you used a scanner to see what percentage the PCM is commanding for the fan? I would also use a scanner to see the coolant temp and compare it to the gauge. Quote Link to comment Share on other sites More sharing options...
AJ Posted September 21, 2007 Report Share Posted September 21, 2007 did you have the PCM reprogramed when you replaced the fan clutch? there was an update for it. was it a GM fan clutch? there was also a problem with the fan clutch rubbing throught the wire harness and causing it not to work. put a glove on and see if you can stop the fan with your hand, if you can there is your problem. Quote Link to comment Share on other sites More sharing options...
nathan Posted September 21, 2007 Author Report Share Posted September 21, 2007 The fan clutch is engaging and increases to about 45% at 225F when it was shut down as it kept going up (this is from mechanic) I just saw it heading up and shut it down when the gauge on the dash got to 240F and the overflow started to boil over. I had him also check the gauge on the dash verses the actual temperature and they were within 5 degrees of each other so the gauge is okay. I would have thought maybe a gauge problem too except for the obvious boil over into the overflow tank. Would a clogged radiator still "flush" okay? I don't know the exact design on these radiators. Quote Link to comment Share on other sites More sharing options...
nathan Posted September 21, 2007 Author Report Share Posted September 21, 2007 No I did not have a reprogram done, but the clutch was a brand new latest model clutch and it was installed over a month ago and there were no problems until Tuesday. I was able to stop the fan at low speed, but did not attempt to once it started to get hot. Quote Link to comment Share on other sites More sharing options...
AJ Posted September 21, 2007 Report Share Posted September 21, 2007 well if you can do it when its hot then you have a problem, just because the fan clutch is new doesn't mean its a good unit. feel the lines in and out of the heater core and see if there both hot as that will help to see if water is moving like its suposed to. check the belt and make sure its not worn out and has good tension. if you have a blockage in the system somewhere there is only one thing that will clear it out and its a Prestone heavy duty 2 part cooling system flush. its not one of those coolant exchanges that are a waste of money but something that you have to drain and flush you system with water to use, the first part is the flush and the second part is a neturalizer for the flush. it takes a few hours to do but nothing works better than this stuff....nothing. Quote Link to comment Share on other sites More sharing options...
nathan Posted September 21, 2007 Author Report Share Posted September 21, 2007 Any thoughts on the lower hose that has the thermostat housing being really cool? That makes me think radiator blockage. Quote Link to comment Share on other sites More sharing options...
Guest Removed Posted September 21, 2007 Report Share Posted September 21, 2007 take the temp gun across the radiator , and look for cold spots in the core...if you have a cold spot(temp way low) you have aa blockage in the radiator! Quote Link to comment Share on other sites More sharing options...
nathan Posted September 21, 2007 Author Report Share Posted September 21, 2007 I agree, I felt the radiator after it overheated and the whole bottom was cool to the touch while the top was super hot. It has to be a blocked radiator. I am going to investigate HP options. AJ, I looked on the prestone site and they do not show the 2 part flush on there. Have any idea where I could get it? Quote Link to comment Share on other sites More sharing options...
AJ Posted September 21, 2007 Report Share Posted September 21, 2007 i'll try and get you a part number, i know it had a GM part number the last time i used it. Quote Link to comment Share on other sites More sharing options...
nathan Posted September 23, 2007 Author Report Share Posted September 23, 2007 Flushed the radiator, it does not seem to have a blockage, but it is one of those non tubular types so who knows. I ran a bunch of water through the system and the temperature seemed to stay in the 210 ranges all afternoon without the fan clutch. I hooked the fan clutch up and noticed that the car started to overheat again. I was able to stop the fan without any problems at 230F so I called NAPA and got a new fan clutch. This also did not solve the problem, but I could not stop the fan when the truck started to get hot. I finally went and found a TSB that describes the problem it is 012103, overheating with limited or no heat from the heater. Quote Link to comment Share on other sites More sharing options...
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