Overheating

[kenshin3]

So this morning I went to go get some new tires but on my way my car started to overheat so I pulled over and noticed the radiator was leaking so I let it cool down and drove 5 minutes to my grandmas house and changed out my radiator but when I started it it was still overheating I’m assuming and really hoping it’s just cause I didn’t think to purge the system of air until after. I also didn’t see any other leaks and the oil and dipstick look fine there’s also no smoke from the exhaust so I don’t think it’s a head gasket. But I would like to know what you guys might think could be causing the engine to overheat as well as if anyone could tell me how I could purge the system maybe without the spill proof funnel everyone uses in the videos just to save a couple bucks

[VStar650CL]

Usually if you park on a steep uphill and hold the revs around 4K for a minute or two with the cap off, it will clear any air out. Then top off if needed while you're still on the uphill. Check your thermostat too, after purging. If the hoses are still lukewarm when the car overheats, then you probably have a bad 'stat.

[kenshin3]

Thank you I was able to get the air out and now the cars running great

[VStar650CL]

[Nameric]

I have a similar issue with the car overheating. I have gone through the burping process but I am unable to stop it from slowly overheating. The fans on the radiator are turning on once it is up to operating temperature as expected. When I was burping it and the fans turned on I was able to increase the rpm's and the filling bowl attached to the radiator reacted by filling more as the rpms increased and returned back to normal when it was at idle. There is no air escaping from the purge valve near the firewall when the cap is loosened. Some fluid escapes but no bubbles come. The car's heater is not working properly either. I have had the unit on jack stands to burp it and it seems to have no more air in the system to give no matter how long I keep up there and cycle it from cold to operating temperature to rev'd up at 2500 for 10 seconds at a go. I do measure a temperature delta of ~ 25 degrees from top hose to bottom hose on the radiator during fan engagement. In my mind this means that the radiator is doing its job. The unit has fresh oil and fresh radiator fluid as part of the repair exercise when replacing the water pump. The old water pump did not appear to be defective or have damaged seals when it was removed. I replaced it because I was trying to remove a variable. Any thoughts would be helpful.

[VStar650CL]

The heater not working right means it's almost certainly still airbound. There's no heater control valve on your M, the core either has flow or it doesn't. Jack stands won't always do it, and 2500 RPM definitely won't do it. To purge without the vacuum tool, we generally jack the front of the rocker about 2 feet, which equates to about 15 degrees (27%) slope, and hold 3500~4000 for at least 60 seconds.

[Nameric]

Okay. I will try again at a higher angle. Thank you for your input. I have a new radiator ordered just in case this doesn't work. I will give you feedback once I have tried to burp the car again.

[Nameric]

The heater is now working. The vehicle continues to overheat when driven even a mile. During the process of revving the engine the liquid overflowed the radiator mounted filling container and began to "boil" I am not sure if this is normal but I shut it down.

[VStar650CL]

Sounds like maybe a stuck thermostat. Or if you already changed it, did you maybe get the burp hole in the wrong position? It has to be between 10~2 o'clock, otherwise the 'stat housing will pretty much stay permanently airbound.

[Nameric]

Hi VStar650CL. The thermostat was replaced with an infiniti OEM unit during this chase of the overheating. I didn't realize you could do anything with the unit other than install it. It is shaped so that is only bolts on one way. Is there an adjustment inside the unit for the orientation of the hole?

[VStar650CL]

Nope. If the burp hole (also called jiggle valve) is in the wrong spot, the only fix is to pull it and turn it the right way. Ideally it goes at 12 o'clock, but anything between 10~2 will let it do its job.

[Nameric]

I will see what position it is in when I replace the radiator. Hopefully the new radiator comes in soon. Thank you for the input. I will update this post and perhaps become enlightened enough to share the solution. Is there a normal delta between the radiator hose temperatures that would indicate if the fans and radiator are functioning normally?

[VStar650CL]

Is there a normal delta between the radiator hose temperatures that would indicate if the fans and radiator are functioning normally?

Not really. There's a normal delta for each model under given conditions, but it isn't like anyone publishes that. No one even publishes the information you'd need to calculate it, like flow rate @ RPM. Keep in mind that it's a closed-loop system, the thermostat is designed to regulate flow at any heat load below maximum, so the radiator never dumps any more heat than the engine requires. Not that I've done any exhaustive testing, but I've measured drops as small as 10 degF and as much as 40 degF on various models in various conditions.

[Nameric]

Is there a normal delta between the radiator hose temperatures that would indicate if the fans and radiator are functioning normally?

Not really. There's a normal delta for each model under given conditions, but it isn't like anyone publishes that. No one even publishes the information you'd need to calculate it, like flow rate @ RPM. Keep in mind that it's a closed-loop system, the thermostat is designed to regulate flow at any heat load below maximum, so the radiator never dumps any more heat than the engine requires. Not that I've done any exhaustive testing, but I've measured drops as small as 10 degF and as much as 40 degF on various models in various conditions.

Thank you for the input. The new radiator arrived but it was damaged so I will update once the replacement is installed. In my mind this is a simple loop to cool the engine and the only throttle point is the thermostat. With brand new OEM parts for the thermostat and water pump I thought this would be a breeze to fix. I was incorrect.

[Alffie]

A new cap, thermostat and gasket cost me $92 from the dealer but it was actually the upper radiator hose that split at the bottom. Local auto parts stores dont have it. And the dealer wants $88. Got it from one of those Infiniti parts site for 20 something