Before this ends up costing me an arm and a leg to have someone fix i was hoping to get some advice. My fans wont kick on unless i turn the ac on i need 2 replace two more of the 3 relays tommorow and i have replaced the front temperature sensor below the water pump and thermostat. the car over heats when idling and is becoming a problem. My heater core is by passed but is getting fixed very soon i want to fix this problem ASAP before the mechanics charge me 500 dollars to redue everything i have done so far. Someone said briefly while i was having my engine looked at before a race to ground something but i didnt catch it i will see him saturday but i dont want to wait so long.

Thank You any help is appreciated

 

LT1CorvetteBoy58,

What year/model? (sounds like it might be a 95 or 96?)

Stock fan/ECM programming?

Do you have three (3) relays on driver side of radiator?

IF fans come on with AC, then wouldn't that mean the relays are fine?

Are the fans coming on at high or low speed (assuming 1996)?

FYI, the temp sensor in the water pump housing is the same one that feeds the ECM and the digital dash temperature reading. So unless the digital dash was misreading relative to an actual temp reading with a water or IR thermonitor, then it was probably ok.

BTW, 'grounding something', may have implied that the relays work through the ECM, such that the ECM decides when it is time to turn on one/both fans, high/low speed, and does so by grounding the appropriate relay. So, the relays should have power on the hot side, and by grounding the negative side, it should activate the relay and thereby the fan(s).

 

What temps are you showing?

 

220-250 sometimes more but i turn a/c on b4 it becomes severe
its a 95 lt1 with stock ecm and when the a/c turns on it's both fans like it should be... Im about to put a standalone temperature switch in there if this keeps up.

Is there anyway i can bypass the ecm completely to have the fans running all the time without putting a ghetto switch on there it is way to nice to do that to the poor car.

it also has minimal other issues i spent at 86,000 miles $2400 for a performance rebuild of tranny with new rear main engine seal and HD Torque converter with 3 year warranty on the tranny. now i want to finish by fixing the fan issue. I also cant seem to find valve covers for this corvette anywhere ecklers charged 200 a piece and i have seen jegs and summit ones go for 200 together but the pcv is at the top so i need to put a breather on it will that work or do i need to run that pcv into my intake like it is now. I am sorry for all the questions but i would really like to show my father i am serious about keeping this corvette looking good and running good it is really sticking to me it has something to do with the old style greenwood kit just sets the car apart from the rest.

Thanks yall!

 

This will bypass the PCM

http://www.ecklers.com/product.asp?p...6&dept_id=1252

 

hmmm wow so maybe im not giving my fans a chance to kick on according to this but i defenetly like to have the vette between 180-230 not above that.

 

Heh?

 

Factory settings for your 95 are main fan on at 227-228 and the auxillary doesn't come on until 236F. I went with a reprogram and a cooler t/stat, stays about 185-190 all the time now. Valve covers for the LT1 are expensive, and you have to trim the alt bracket to even make them fit. GM went to the composite covers to muffle engine noise and there are a few ways to cover them instead of chaniging them out (pictured below).

 

Are you going by the analog gauge or the digital readout? The analog one looks scary because these cars do run pretty hot. Seem to recall the factory setting does not turn the fan on until 228*
There are ways to make it run cooler but you may be fine. Do a search on cooling problems, you will find a common problem is debris in the radiator, they are bottom feeders and suck up junk like a vacuum cleaner, good luck.

These covers fit with no modification required, but they are NOT cheap.
http://www.parts123.com/parts123/yb....Z5Z5Z50000050F

 

See I can work with those covers they arent stock and cost less then the stock ones from ecklers. but i have also just noticed that ecklers sells grommets for the vette because 2 of the grommets are leaking where the bolts connect so i will order those maybe i will replace all of them at that same time I also just ordered that part that bypasses it so thanks a bunch guys cant wait to see the look on my dads face when that junkbox corvette (hes a ford guy) runs reliably.

 

Presuming ambient temperatures in 80's or less.

Sitting in traffic A/C off, not moving, 220-240 could be normal, 250 is high (presume your reading the digital dash temp).

By contrast, sitting in traffic, A/C on, temp should be 195 - 205.

By contrast again, driving reasonable speeds, regardless of A/C on/off, temp should be 200 +/- 5 degrees.

You mention 'overheating'. Is it loosing fluid, or has it ever? If so, maybe the thermostat is not operating correctly, or is the wrong one (the LT1 thermostats are unique in that they have an extra plunger on the bottom side to close off a bypass when they open). If your not sure, just replace it, it's pretty easy, but be sure to use the correct one (e.g. use ACDelco to be sure). BTW, I had a bad thermostat after a stupid error (left cap loose). It actually seperated the extra plunger from the main plunger causing my temps to run 10 degrees above normal.

If your readings are different than above, first lay on your back under the front of the car and look up at the front of the A/C condensor. Remove all debris and consider using a tooth brush to loosen some of th imbedded debris, but be sure to be gentle and like our teeth, brush with the directions of the fins so as to not bend the fins.

Then look in-between the radiator and A/C condensor. Your year may have the same opening on the passenger side where the A/C lines enter. You may find lots of debris therein too. The passageway is just large enough to very carefully get a shop-vac hose into to suck out all the leaves, etc.

Lastly, inspect the plastic air-dam and replace if worn down from hitting things or its bracket is bent such that it is not scooping the air. This simple piece of plastic is very important as it picks-up the air that would otherwise just go under the car and redirects it up to the A/C condensor and then through the radiator.