Brought the car out of hibernation yesterday and did an oil change. I had 15w40 in there before and put 10w40 in yesterday. Now when I'm idling the temperature climbs right up to around 210+ and drops back down when I'm driving. Fine on the freeway, could be cooler at 35mph. Last year it stuck around 185* normally and would slowly climb up idling on hot days. It's not hot out today and it was still climbing at idle. I figured it might be the fan clutch, I spun it by hand when the engine was cold (and off, not to worry) and it goes maybe 3 times around before stopping, I don't think it's conclusive enough to say for sure it's bad since it does engage when the engine is hot. Topped up my coolant yesterday as well, oil and coolant both at proper levels. Strange to me that it's only started doing this now, when the only thing that has changed was the oil viscosity. I wouldn't think the drop from 15w40 to 10w40 would make a difference like that but who knows? Oil pressure is fine, sitting at about 15 when warm at idle, slightly lower than with the 15w40. Either I'm missing something or something stopped working properly over the winter. Car was stored outside under a car cover if that helps. Any ideas as to what's going on? Want to get this fully ironed out before it starts warming up around here.
Awesome, that's all I was hoping it would be. I've heard that it's good to replace the fan clutch and the water pump at the same time, is that worth the hassle or just leave it be until it needs to be done?
No, just replace the clutch. If you want to check the water pump, grab the fan and try to wiggle the pulley. If you see the pulley wobble, the water pump shaft bearing is on it's way out, and the seal is next. If it doesn't wobble, the pump is fine, leave it alone.
If you can give it a spin with the engine off and it continues to spin 3X as you stated, then it is freewheeling. It might tighten up some with a warmed up engine, if it is a thermostatic clutch, but it will probable not pull as much air as it was designed to do.
Come to think of it I don’t remember hearing the fan roaring at all with this car. I think the clutch has been on its way out for a while. That said, it definitely was not roaring yesterday.
Lock the fan up with a couple of cable ties, wire, or strap so that its not a fan clutch anymore, for a test, and see if the temp at idle stays lower. After about 40 mph the fan does not do much for any additional cooling.
I like to get the engine up to operating temperature and then watch the fan when I shut off the engine. The fan should stop, a bad clutch will continue to spin.
Ok, fan clutch was definitely bad. I now know what you guys were talking about by it roaring. Nice to have that done. That said, the car is still overheating at idle. New fan clutch definitely helped, but the temp is still climbing. I checked the coolant level which is fine, boiling point is at 262 so that's ok. None of the hoses are collapsing from what I can see, I put a new rad cap on last year. On my test drive today temps stayed very nicely around 180*, and started to climb slowly at red lights. Slower than before, and only peaked at around 220* after I got into my neighbourhood just before parking. Timing is where it should be, nothing off there. With the new fan clutch once the temps start rising I can rev the engine a bit and it'll start to come down. Temps are more stable in park, idle in drive is around 600-700 rpm and around 800-900 in park. Just now when I was checking timing, temp was about 190* in park. Put it in gear to see what would happen and after about 10-15 seconds it shot up to about 210* and held there, but continued to climb slowly. Put it back in park and revved it and temps went back down. Wanted to get some of your opinions on this before I go try anything else. Next thing I could think of would be the thermostat, and I'm sure flushing the system wouldn't hurt. Edited to add: went out and squeezed the hoses, pretty much all of them sounded pretty crusty in there. The lower rad hose was particularly bad, it's pretty much rock solid and it feels like there's quite a large mass coming off the radiator. Not to mention the coolant inside the radiator looks pretty gross, kind of a light brown. I'm willing to bet that this is what's causing the overheating issues. I'll replace the hoses, flush the system and swap the thermostat while I'm in there and hope that's all it needs!
Are you sure of the timing? When was the last time you had a light on it. If the radiator is old, it is most likely clogged with scale.
Checked with a light just yesterday, but it’s very possible I didn’t read it right. Still getting the hang of it That’s where I’m at with the radiator too. Going to flush it and see where that gets me but I’m not opposed to shelling out for a new one if need be.
Do yourself a favor, if that's the original rad yank it out and put it in your shed. Get yourself an aluminum 2 row rad with MINIMUM 1" tubes to go along with your new hoses, Tstat and fan. I would recommend flushing the block out really good before you install any of the new parts. If you want to make sure you have good flow grab a HP water pump from TA or a Flowkooler pump.
Ok, FINALLY got some time to flush the system. I don't like how it's going. All that came out was maybe 4 liters of rank brown coolant. Interestingly enough the overheating wasn't as bad as it was when I made the post, it would sit around 190-200* at idle and I could keep it in check by putting the car in neutral while I sat at the lights. What scares me is that it looks like there's a thin film of oil on top of the garbage that came out. Only a film, the rest of the coolant was dark brown but as viscous as water, no milkshakes happening here. I checked the spark plugs (new since last year), and you can tell they've been probably overly hot, but they're not in terrible shape, and none of them have that steam cleaned look you'd expect from a blown head gasket. Other than the oily film in the coolant there really aren't any other symptoms of a bad head gasket. Swapped the upper and lower hoses for my new ones, and put the new thermostat housing on as well without a thermostat in it for now, thinking I'd be flushing it. Unfortunately in the process of taking the lower rad hose off, the outlet came off the radiator with it and now doesn't seal back to the radiator properly. I tried getting it back on tight, hammered it on there enough so that when I shook the outlet the whole front end shook as well. Even then it's still pissing any water I put in out the bottom. So, how much of a concern is the oil in the coolant? As for the radiator, I'm looking at a 2 core Champion with the option for 1" tubes, product code 161. Only thing is I'm not sure if it has a heater hose, and I believe there is one on the stock radiator. I'm open to suggestions but I don't want to spend more than $300 USD on a new radiator if I can help it. Also, here's the link to the radiator in question: https://shop.championcooling.com/Pe...981-1982-1983-1984-1985-Buick-Riviera-SKU-161
