Link: http://www.jetchip.com/products.asp?pid=18617

Anybody used this before?


Now on to overheating

My car was running 210* on the highway today. It's usually always ran 180* on the highway, granted today it was 100* out. It seems like it might be overheating. I know when the fans come on... I've let it get as high as 230* idling in a a parking lot before i turned on the heat to let it cool off.

My heater doesn't work very well... I think the heater core is clogged. Would this be why my car is getting so hot? When I first got it it ran 190* -- maybe 210* if I did a lot of idleing now it's like 210 all the time and 230 if I do a lot of idleing and I won't let it get any higher because I'm **** about blowing a headgasket or something. I mean our cars have aluminum heads.

Here's what I've done to correct the problem:
- Replaced Tstat w/ Hypertech 160* (Yes it's a LT1 - from Autozone)
- Replaced Radiator Cap w/ new one from GM. (One time when it was 230* I shut it off and popped the hood... coolant was escaping from the resivor)
- Flushed Radiator - Coolant looked fine.... ~ 5qts.. Tested the freezing point and seems pretty close to a 50/50 mix.
- Added one bottle of Water Wetter (coolant temp reducer)


Low Coolant light started coming on, I've been checking the levels frequently - I think it just randomly broke.
No coolant leaks detected.

I have a fan switch and need to install it. I am also waiting for someone to get thier software to tune my PCM for a 160* stat.

Possible solutions to my overheating?
Radiator Clogged?
Heater Core Clogged? (I don't get much heat - dad says it is the Heater Control Valve)
Water Pump on its way out?

Thanks for any advice.

 

If your heater does not work well, then flush the heater core. Otherwise, it does not seem like you have any overheating problem at all. Everything else you describe sounds normal to me. The fans don't even come on until 226°, so it's going to get to 230° with ease. When it is 100° out, it's going to run a little hotter.

Please make a sig for your car, so you can get better and more accurate tech responses. Not all years are the same, you know.

 

It run's hotter than it did when I got it, or so it seems.

Sorry it's a....
'94 Z28 - A4, 3.23, 135k mi
stock opti / wp to my knowledge
shorty, !cat, flow, K&N cai

 

man...even in the dead heat of summer here in florida, my old LT1 would run 175-180 on the highway with the 160stat in it.

the tuning for the stat is only going to affect the temp when you are sitting still, are in heavy traffic or going really slow. as long as air is flowing over the radiator it should cool it enough to keep the fans off. i ran GREAT for 2 yrs with a 160 stat and never had anything tuned.

sounds to me like there is a water circulating problem. not sure how the heater core affects flow. but i'd start there and work your way to the water pump.

 

Was it 100° when you got it? When it is that hot out and the engine heats up from the car not moving much, it will take a little while of constant driving in free air to cool it back down to where it was before temps started rising (assuming you are driving it normally and not hammering on it).

Does your 1994 have the 2 or 3 relay fan system?

 

Nah, but i mean it's been in the 80-90's easy.

I don't beat my car... i pretty much daily drive it... maybe a WOT 0-60 once a week or something to keep the carbon off the pistons.

Today its probably 100 as well... drove 7-10 mins to the store... no super excesive stopping, all city however. About 210*

Then I drove to the bank 5-7 mins all city as well.... some idleing b/c a main intersection light was out due to construction. About 225-235*

Another 5-10 mins back home and it was still 220-230* so I turned the heat on and let it cool off to about 210-215* before I shut it off

(I turned the heat on about a mile from home)


Not sure if its 2 or 3 relay, how do I check?

 

Check under for an obstruction.. plastic bags are common Another thing to look for are the plastic pegs that hold the plastic above the front of the Rad in place. After a rebuild, these were not put in properly on my car and the car ran unusually hot on the highway only! When going fast enough the plastic would be pushed down onto the surface of the AC condensor blocking air to the Rad causing heat to go way above normal. Slowing down allowed the piece to pop back off the surface and temps would go back down.

 

no obstructions.

what plastic pegs are you talking about? picture?

 

I've had the Jet switch in my car for years now. Works great.
You will need an 8 mm drain plug socket for the install.

 

I don't have a picture sorry
I've seen some cars without this plastic "baffle" held in place by pegs infront of the rad too. I don't know if it was because they didnt have AC or if it was because the owner removed it at one time...

The pegs are 1 way push in type things. Looking in from the hood they shoudl be just behind the washer fluid resevoir (and down a little bit).
I seem to recall them being beige on my car years ago (i've since replaced them with black ones)

 

Still sounds very close to normal to me.

In the fuse/relay panel under the hood, count the fan relays.