nathan.chase Posted August 15, 2006 Share Posted August 15, 2006 This is a follow up on an old post were I was told to check if the radiator was clogged or if the pump was shot. Full coolant new thermostat and equal in and out radiator temp. new thermoswitch when looking into the radiator I see some movement of coolant when the engine is on. Hard to see but it is something QUESTION: Does this definitely mean good water pump? After warming the 87 gl up, I felt the radiator from top to bottom underneith the auxiliary fan. this fan did not run so I figured it was the best place to feel the radiator. Radiator was HOT at the top and the bottom 1/4 was COLD. QUESTION: Does this temperature difference mean a clogged radiator or is it that hot water rises and cool falls? There did seem to be a quick change from hot to cold with no middle ground. I repeated this test 3 times for accuracy. Link to comment Share on other sites More sharing options...
NorthWet Posted August 15, 2006 Share Posted August 15, 2006 Radiator is partially plugged. Maybe half or better. "hot water rises" doesn't count when all of the water is hot (has to have something to rise within) and it is moving in a turbulent environment. Save yourself some headaches and get a radiator. They aren't too expensive online (radiatorbarn.com is one that I plan to try) and will give you years of worry-free driving. Old radiators are just failures waiting to happen, and these engine do not like cooling system failures. Link to comment Share on other sites More sharing options...
nathan.chase Posted August 15, 2006 Author Share Posted August 15, 2006 my one reservation is if the pump is not working strong enough to full circulate the water through the radiator would this mean discrepency would arise in the temperature of the radiator or would it just be evenly too hot? Link to comment Share on other sites More sharing options...
daeron Posted August 16, 2006 Share Posted August 16, 2006 not really. the water pump is going to suffer from a clogged radiator, not vice versa.. it sounded like you might be trying to hope a new water pump would "puch through" your clog.. and its not. its not worth it either. to replace the radiator takes like ten minutes, twenty if you have an auto trans like me and have to find a way to get a screwdriver on those hose clamps for the oil coolant lines right up against the #$%*(^ing fenderwall... and yah the radiators like 100 bucks.. but it is SOOO worth it, even if it DOESNT fix your problem, to know you have a nice new rad in there and that is NOT your problem. plus its easier than a water pump. Link to comment Share on other sites More sharing options...
Syonyk Posted August 16, 2006 Share Posted August 16, 2006 While you're at it, I'd strongly suggest replacing your thermostat as well. A bad radiator (overheating coolant system) will often push an old thermostat over the edge. -=Russ=- Link to comment Share on other sites More sharing options...
NorthWet Posted August 16, 2006 Share Posted August 16, 2006 While you're at it, I'd strongly suggest replacing your thermostat as well. A bad radiator (overheating coolant system) will often push an old thermostat over the edge. -=Russ=- Good advice, and cheap, too! Water pumps rarely if ever fail to pump. It would take something catastrophic to cause this (like a seized bearing/shaft). Their usual failure is leaking. Cold zones in a radiator, especially not just at the very top (which could be coolant level) is an indication of plugged tubes in the core. Link to comment Share on other sites More sharing options...
nathan.chase Posted August 17, 2006 Author Share Posted August 17, 2006 I have replaced the radiator. it took me more like two hours to do. I unboldted the main wind colar and jimmied the radiator out with everything else on it. I replaced it without the auxilary fan which made it go in very easily. nonetheless it took a long time for those two or three barried bolts to finally get tightened down. I was actually hoping that this radiator is the problem so I don't have to do a waterpump. According to the last owners mechanic the pump and computer are shot. According to me the thermoswitch wasn't working, and the radiator had cold bands on the bottom. Makes you wonder when kind of mechanic this guy was. I had a cold band on the top of the new radiator, I guess air bubbles. is there a good way to refill a radiator? I usually pump the hoses and try and burp it. turned on the car too. does the air work itself out? Thanks for your help and I will soon test the overheating problem on a 14-18 hour drive from Vancouver to California on friday. Should be fun! Link to comment Share on other sites More sharing options...
NorthWet Posted August 17, 2006 Share Posted August 17, 2006 Everybody has their favorite ways to completely fill the cooling system. Pumping the hose sounds OK. Trying to get car in a nose-up attitude will help. I usually try to do my best and then have patience, sometimes taking a week to totally fill a drained system. Link to comment Share on other sites More sharing options...
rllywgn Posted August 17, 2006 Share Posted August 17, 2006 just to clarify you did re-install the secondary electric fan yes? a must for an a/c car rllywgn Link to comment Share on other sites More sharing options...
daeron Posted August 18, 2006 Share Posted August 18, 2006 i took my thermostat out and that also greatly simplified filling the thing with coolant.. but, just a point. im NOT necessarily recommending that. i would also highly recommend re installing the electric fan if you havent already.. it is there as a supplement for the clutch fan for A when the AC is on and B when the radiator temperature exceeds a certain point. this is what the thermoswitch is for. My thermoswitch is bad, so i bypassed it with a jumper wire going from one side of the harness plug to the other. this fools the car into thinking the thermoswitch is always "on" it also means the fan is always on when the key is on accessories or on...so do what you want. I just say what i did to give you ideas. Good luck with the trip, just in case, dont forget to bring a good large rag.. GOD FORBID Worst case scenario, if you have to refill while hot, do it with the engine running and POUR SLOWLY so the cold water can heat up a bit before it gets into the block. adding cold water to a hot engine is a BIG no no but if you can do it right, and have no choice, its better than letting the engine run with no water at all.. and if the water level gets below the level of the pump, thats what you are doing, so... have a big heavy rag if you have to open the radiator cap under pressure.. that way the steam and water go onto/into the rag, and not your face. OBVIOUSLY this is all NOT what you ever want to do... but you say 18 hour drive.. i figured i would mention it for that "just in case" scenario. Incidentally, after i was born my mom shared a room with a woman who had just given birth to a son, whom she named Justin Case. Link to comment Share on other sites More sharing options...
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