Help re: intermittent overheating

[LSB4Me]

Hah! T-Bone will enjoy the irony there.

I will give some thought to cleaning the radiator but at $300ish, it’s probably best to start fresh as the cooling system is one of the last mechanical components to be baselined. I’ve been through everything else in the last 3 months. Good times.

Copy that. Genuine radiator it is.

Question 1: Does the fan clutch make a noise (a rattle, perhaps) when it’s on the way out?

Question 2: I will replace the hoses with the radiator. Silicone (Mishimoto?) or stock here again?

[heinzboehmer]

If so, I have questions about radiator brands/choices in the next round.

Number one choice is stock. Second choice would be stock.

There's been a bunch of threads where people have issues with aftermarket radiators. Resolution is always to be going back to a new stock radiator.

[heinzboehmer]

Please no one say "air". System is self bleeding.

Ah sounds like an issue with air...flow


Yeah your radiator is probably old and filled with debris from the road or has a bunch of bent fins. This won't allow enough air to flow through it and cool the liquid inside it.

If you want to track down the issue before starting to swap out parts, you could remove the radiator shroud, move the AC condenser out of the way and try to blow out any debris that's caught in the fins of both. Make sure to blow it out in the opposite direction that air normally moves (i.e. blow back of the car to front), so that you don't just lodge everything in further. If the issue goes away (or gets better), then a new radiator should take care of it. Otherwise, fan clutch would be the next culprit.

[LSB4Me]

Radiator and/or fan clutch. A new radiator alone would solve your issues I bet. So much so that you could remove the fan and still not see over heating.

Please no one say "air". System is self bleeding.

*heart emoji*

Follow-up detail. When the coolant temp starts rising, the AC seems to lose some of its oomph—both fan speed and temperature. Does that confirm the suspicion of radiator/clutch fan?

If so, I have questions about radiator brands/choices in the next round.

[Tbonem3]

Radiator and/or fan clutch. A new radiator alone would solve your issues I bet. So much so that you could remove the fan and still not see over heating.

Please no one say "air". System is self bleeding.

[LSB4Me]

Hi Everyone:

I am have been having some strange overheating symptoms and am hoping that you all can identify the part(s) that need changing.

After a decent testing period, I can say that the coolant temp starts to climb: (1) on hot days; (2) with the AC on; and (3) when the motor is being run harder—meaning, shifts at 5k+ or while under load (uphill). Another clue is that the coolant temp returns to the midpoint when turning the AC off. And yes, I can hear the aux fan doing its thing and see it running when I get home before shutoff.

This car is new to me and my records are good, but not great. A challenge here is that my trusty mechanic doesn’t like to “throw parts” at a problem, which is typically my go-to—if it ain’t behaving like it should, replace everything. I still might do this and take the heat from the shop.

With that said, it seems like the cooling system can be broken into two parts: (a) the radiator/fan side; and (b) the water pump side.

Any thoughts or opinions on which of these two is the likely culprit? I would like to start with a targeted approach, if possible.

*Disclaimer: I’ve read all the thread and bought the “easy” sensors. I will install the lower radiator hose sensor this week, but am not optimistic given the above.

Thanks in advance!