J-money

I know this is a very vague and dull question but.... Me and my gf both have same vehicles 92 5.0 RS's. They vary drastically in coolant temps. I have driven mine 11-12ish years and its never really been "normal". When dad gave it to me it had a problem like most overheating in traffic and going down dirt roads slow. He had also straight wired the fan to a fuse to make it run constantly, because something about the fan wires overheating. I never fixed it right but I have it goin to a toggle switch I can control. Eventually I got a new radiator use a 180 thermostat and can keep it from running to hot. I rarely make the fan come on.

My girlfriends is a different story, since we've been together I have Put a 160 stat in hers, flushed system, replaced radiatior cap, upper hose among a ton of other non related repairs. Her ex drove the car with no stat in and it still ran pretty hot. This car with a lower stat than mine and fan that works still runs much hotter than mine (220-245) city (190-220) highway. Mine is 160-170ish highway, 180-210 city usually without using my fan unless its really bad traffic.

So where exactly does a normal running engine stay at? once 220+ her needle seems to fluxuat alot also.

battman

iTrader: (2)

They should run around 205 from the factory if i remember correctly. Is the lower air dam installed and not damaged on the GF's car?

Running down the road they should run at whatever temperature thermostat is installed if the cooling system is functioning properly. setting idle they will run at whatever the electric fan is set to turn on at.

GASPEDDLER

iTrader: (2)

My car's gauge reads about 160 most of the time but when I check the temp at the Tstat housing with my infrared thermometer it shows 200. So for my car I would say 200 is about average.

J-money

Yes the air dam was the first thing I checked for. It appears to be intact. I am going on the assumption that the radiator is good, it was supposed to been replaced only a few years ago. I did notice today backing it into the driveway it seemed to be kinda "bouncing" between 220 and 245. I am beginning to wonder how accurate the gauge is.

J-money

40 degree difference? Thats more than I would have thought.

GASPEDDLER

iTrader: (2)

Saturday morning while driving to a car show I noticed the gauge was no longer operating. It stayed at the 100 until I idled my car for a few minutes but then only climbed about 5 degrees. After arriving home I again checked the temp at the stat housing and again it showed 200 degrees. I also checked the sender connection which was fine and then grounded the connection to the block which caused the gauge to immediately peg at 260. I took this to mean my wiring and gauge are good but the sender may not be, so I ordered a new sender just yesterday. My guess is the sender must have been going out for some time which might explain the 40 degree difference.

J-money

The sending unit for the coolant gauge is the one on the intake manifold next to the t-stat housing? Does that sensor also control when the fan comes on? I can hear the fan kick on SOMETIMES once the gauge gets up to 245ish. Also sometimes i can get it to come on with Key on engine off once it gets pretty warm. She has owned the car since like 1993ish, and said that it has always an fairly warm (above the 225 mark) even new.

I have even noticed on hers the second you start to climb a hill even at highway speeds 55+ the gauge starts to climb. Mine never does this unless its like going up a long mountain.

GASPEDDLER

iTrader: (2)

I believe the one you speak of is the temp sensor for the ECM which controls the fans. The temp sending unit is located on the driver side head below the exhaust manifold and between the first two spark plugs.

dmccain

iTrader: (2)

Temp sensor on TBI cars is on passenger side head I believe and you can swap it out for one that turns the fan on sooner than the factory which on my car doesn't even come on til somewhere around 230ish. I run a 160 thermostat and when mine creeps above 220 or in heavy traffic I run the A/C to keep both fans turning and it usually doesn't get above 180 on the hottest of days in traffic. The sensor on the drivers side only runs the temp gauge on the TBI cars anyways.

J-money

Thats the one kinda above the starter. I wasn't sure if that one was for fan or not. I'll crawl under it and inspect it.

someone972

iTrader: (2)

If I remember correctly these cars came stock with a 195 degree thermostat, which is what mine has. With that it usually stays below the 220 mark by about a 1/6th of the gauge while cruising and will climb to slightly above the 220 when sitting. I've never verified if the temp gauge is accurate or not. Note that the temperature gauge is non-linear, there's much more change in the first half than in the second half. So it makes sense that it appears to fluctuate more when it gets up to temp since it's showing a smaller range. I don't like it to get much hotter than 220, and it used to get up to 230+ before I put the air dam back in. Unfortunately can't be much help as to why your gf's car might be getting hot so quick.