TucsonErik

So, I have a mostly stock 5.0 in my '91 hatchback. After taking parts back off I am left with 10:1 pistons and E303 cam. Motor is otherwise stock. I have a larger (thicker) replacement radiator. Most of the year it runs very cool (way down at the L in NORMAL.) In the summer, in stop and go driving, it warms up to the top of the NORMAL range, but stays cool if I can stay moving on the freeway. It has never actually overheated on me. I 99% sure I have a 160 degree thermostat installed and my theory is that it is too low and not letting the heat actually shed to the radiator. Before I go tearing it apart, and replacing the t-stat, I thought I would come to the well and seek some knowledge / opinions. I am in Tucson, so the summer temps are nice and warm. So, what do you think - 160 degree too low? 180 or 195 would be better? Thanks.

mjr46

overheat conditions in stop and go are not a result of a t-stat issue, your theroy is wrong.........why you ask?? freeway driving you state it's fine,....it is thus an airflow issue or lack there of across the radiator, how is the fan?? = fan clutch?? are you using one?? or an elec fan?? you made no mention of such???

Bubba 95SN

Should be running a 180 stat. Airflow is issue.

AdderMk2

Your fan is ****... get a new one.

kirby82

My 87 gt did the same thing! The owner b4 me had a aftermarket flex lite fan on it. I put a new clutch fan on her and she's been cool ever since!

TucsonErik

I did forget to mention about my fan...

Years ago my fan clutch went out (I think) - anyway, I do remember the plastic hub of the fan had cracks all the way around. I did replace it with a flex fan.

I remember seeing aftermarket steel fans that are compatible with a clutch. Are those any good, or do I need to track down an original setup?

AdderMk2

get a stock setup, most parts houses keep them in stock

Bubba 95SN

LRS # 8600A is about $40 and clutch with radiator air defector is $110

Jfsram

....and 160 is too low.

mjr46

my flex fan works fine in stop and go traffic, but then again I have a oem shroud, do you at least have the shroud still?? if not that may be half the issue