Aardwolf

? Mine has a few small areas of folded over fins. It takes a loooong time with a small knife to fold them back straight. Any tips?

I checked to see if my front radiator booster fan was working, nope it's not! I tried turning the A/C on, and also jumpering the fan. Nothing. The main fan cools the car very well. So I decided to remove it for now. I may fix it or install a different one later. My cruise coolant temp. dropped about 10 degrees. On an 85 degree day I cruise at 194 and get to 198 up a long hill now. That's with a 195 thermo. Before removing the fan she'd run about 205 on a really hot day at interstate speeds.

Mike_88Z51

I used a well used (rounded edges) small flat blade screwdriver. Not any faster probably, but not quite as pointed as a knife. I spent 2-1/2 hours straightening every fin possible. VERY BORING, but worth it. I haven't had to pull the radiator and clean it in 5 years. I use a 180 thermo and similar to your results, I see 179~185 (thermo opening point temps) on a warm day at cruise. Even in traffic on 100 degree days, it has never gone over 217. OF course I installed an aftermarket aux. fan switch from Mid America which turns on the aux fan at 205 and off at 195.

CAJUN C4

Maybe a small hack saw blade??

65Z01

That Booster Fan is controlled ONLY by the Aux Fan switch switch located in block below #1 & #3 spark plugs. If you pull the connector to that switch and ground it the Aux Fan relay, located on the upper left side of the radiator shroud, will close and turn on the Booster Fan.

However, in stock mode the Aux Fan switch is designed to close only after coolant temps hit around 238deg F.

Of course I run a 160deg T-stat with matching Aux Fan switch that is wired to control both fan relays. So my coolant temps rarely go above 175 deg F, even in occasional high 90deg F weather.

I think the only way to straighten bent radiator fins is the slow tedious method you are using.

mikey whipreck

I used a small flat head screwdriver too... slow but worth it- after straightening the fins, cleaning the radiator, and refilling the system, my temps stay right around 195... with a new stock delco Tstat (195 temp).

CentralCoaster

They make fin straighteners for HVAC, but those absolutely won't work on the radiator. The fins are spliced, the only way is to use two small screw drivers, or something equivalent to squish them back to shape.

I did this on a used rad I bought, took maybe an hour to fix.

BCinPhx

I went to a local HVAC place and bought the fin straightener with 6 differrent plastic fin guages (@ $4.) and it has worked pretty well on all my other Chevy radiators - although I havent had to use it on the vette yet. For a cheap price it may be worth a try.

rws.1

Harbor Freight


RADIATOR FIN STRAIGHTENER


One of the easiest ways to make sure your engine runs cool. Straighten damaged fins and remove debris without danger of puncture. Also great for oil coolers and air conditioners. Works on most makes and models of vehicles on the road today, with spacings of 8, 9, 10, 12, 14, and 15 fins per inch.


ITEM 37892-0VGA
www.harborfreight.com

Mike_88Z51

I've seen this value used quite often and I have to disagree. The 88 Factory Service Manual Electrical Supplement says the aux fan switch should ground the aux fan relay and activate the aux fan above 228F (109C). Page 8A-31-1.

I'd recommend trying 65Z01's advice and try grounding the wire that goes from the aux fan switch to the aux fan relay, and see if that fires up the fan. If not, swap in a known good relay and try one more time. If you have an aux fan that is capable of working, it would be a shame not to take advantage of it. The aux fan relay is the same as most of the other relays used on the 88 C4. You can use the horn relay or one of the MAF relays in place of the existing aux fan relay. The aux fan relay on an 88 should be on the LH rear of the radiator shroud. If the relay is bad, I'd get one from NAPA at about 30% less than from a dealer.

rws.1, at $4.99 that fin straightener looks like another "good to have" tool. Thanks for the link.

eschoendorff

Hey! I got one of those!

My experience has been that it works waaaaaay better on the AC condenser than it does on the radiator itself

FWIW...

Bump

My HVAC man told me to use a new wire brush that you scrape paint with. You will have to get the flattened fins started first with knife blade or small blade screw driver. It will also give it the wavy look.

FELNGR8

I used jeweler's screwdrivers. Picked up a set at Home Depot, used the smallest where needed, a sightly larger one for most fins. They come with 6 different sizes in a kit.

merrick

The best thing I have used is a pair of fine tipped needle nose(long and skinny). Sears has them. You can get most of the waves out or prevent from making a wave.