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97 Sho Runs Warm

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My 97 SHO seems to run a bit warm.

I've taken the fans out and blasted compressed air through the rad. I also took a hose and blasted water through it. The radiator, water pump, and thermostat (190F) are the factory, never been changed. The coolant jug, cap, and 1 upper hose have been replaced (prior owner).

It has a new Ford ECT I installed (I busted off old brittle one by accident). The low speed cooling fan kicks on at 215/6 as the PCM tells it to, so the ECT is accurate and working. Dash gauge never goes above halfway. When fan kicks on, it turns off around 209/210. But temp typically goes down to 190s, then creeps back up at idle.

>>>Looking at ScanGauge while driving, I can monitor the coolant temp. Yesterday when it was 65F ambient temp on mostly flat interstate doing 65-70MPH, after car has been running for 20-25 minutes...the car was running at 206F according to the ScanGauge.

Seems rather warm. My 2000 DOHC runs 182-188 in similar conditions. I noticed however...

>>>If I gave the go pedal some extra input, got a downshift of a gear or two and got the rpms up, the coolant temp dropped down to 180, then it slowly creeped back up to 200 or so after I let up on the gas.

What should I be doing next? Pressurized coolant flush? New thermostat? New radiator? New water pump? I want to solve any cooling issues before summer.

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Flush or new pump, IMO. It sounds like there might not be sufficient coolant flow at lower RPMs, i.e. idling or cruising on the highway in O/D (before you get on it).

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Check the pump, many of the older ford cam driven pumps had plastic impellers that would fall apart over time. Be careful not to pop the spring on the tensioner though, an issue that I have had to fix several times, v8 SHO and contour v6 have the issue, there is a tab that holds the spring that sits in the wrong spot. I put the spring back and tap it towards the spring with a hammer and it will stay.

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+1 on the pump. Seems like not enough flow without higher rev's. Plenty of air going through while driving 65 thats for sure.

I doubt thermostat is the problem if it drops down that quickly when you give it some gas. Seems like the radiator wouldn't be clogged either because it actually does drop down the temp with the higher rev's. If that was clogged or thermostat was staying closed more than it should teh temp wouldn't drop with the higher RPM's. Just seems like a low flow issue.

Edited by breeves002

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Your factory thermostat is 192' F, IIRC.

Drive the car. Quit thinking so hard. If the needle never goes above half way, you are golden.

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My Vulcan, with new pump and not a lick of rust in the water usually always stayed around 200-206, and 210 in traffic.

It might just be normal on an engine like that.

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For the day and a half that my SHO ran, I noticed the same thing. it runs just a little warmer than my vulcan. the heat though is outstanding!

$had3 :ford::merc::Shady_J:

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Call me weird, but I notice older Fords always had variant temperatures, warmer when idling, colder when driving (higher RPM's obviously). Newer Fords seemed to lock on to a single temperature, perhaps that's how it was programmed. My neighbor with her 97 T-Bird has the same complaint with the temperature varying, yet the Fusion she has seems to lock into one place on the instrumentation.

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Sounds just like a boat, you can be crusing wide open at 3000rpm and its running cool, as soon as you slow down the water temp will spike for a few min until the water can cool the motor back down. We had a Volvo Penta I/O that would jump up to 3/4 on the temp gauge for a good 30 to 60 seconds after you slowed down from doing full speed. Obviously it had nothing to do with a radiator, the flow of water just fell behind.

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Your factory thermostat is 192' F, IIRC.

Drive the car. Quit thinking so hard. If the needle never goes above half way, you are golden.

Hmm, the V8SHO website says otherwise. Alright, good to know, it's a 192. I just scored a replacement one off of eBay for 8 bucks :D FoMoCo with correct part numbers.

I will continue to drive the car and ignore it then. I am very careful about this stuff and do not want to risk running motor too hot.

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My 97 SHO seems to run a bit warm.

I've taken the fans out and blasted compressed air through the rad. I also took a hose and blasted water through it. The radiator, water pump, and thermostat (190F) are the factory, never been changed. The coolant jug, cap, and 1 upper hose have been replaced (prior owner).

It has a new Ford ECT I installed (I busted off old brittle one by accident). The low speed cooling fan kicks on at 215/6 as the PCM tells it to, so the ECT is accurate and working. Dash gauge never goes above halfway. When fan kicks on, it turns off around 209/210. But temp typically goes down to 190s, then creeps back up at idle.

>>>Looking at ScanGauge while driving, I can monitor the coolant temp. Yesterday when it was 65F ambient temp on mostly flat interstate doing 65-70MPH, after car has been running for 20-25 minutes...the car was running at 206F according to the ScanGauge.

Seems rather warm. My 2000 DOHC runs 182-188 in similar conditions. I noticed however...

>>>If I gave the go pedal some extra input, got a downshift of a gear or two and got the rpms up, the coolant temp dropped down to 180, then it slowly creeped back up to 200 or so after I let up on the gas.

What should I be doing next? Pressurized coolant flush? New thermostat? New radiator? New water pump? I want to solve any cooling issues before summer.

Coolant systems for all cars long ago were 190-195 for smog and for economy. That is the minimum temp for that and nothing has changed for 50 years on that front. It is just the way internal combustion is.

The system design began for front wheel drive requiring electric fans to begin a new program. Later rear wheel began electric fans also and same plan. The thermostat maintains the floor temp of ~190 and the electric fan maintains the lower ceiling of ~210. In between that 20 degree range things are allowed to float. A second stage ceiling is done with the high-speed fan, or second fan as the design is done.

Couple of things. The Taurus has a very small air inlet in front while the Sables use a grille with much more natural opening. The Taurus is more likely to run above the thermostat floor temp if the air is not really cold. And the thermostat temperature of coolant is different from the measured coolant temp as it is in a different place in the flow. Should be relatively close.

Thermostats all use a wax pellet mixed with copper powder. The wax melts at a very specific temp and the copper transfers heat quickly. The wax expands when melting opening the thermostat door. The range between closed and open is quite close in degrees, but there is a time factor as how fast it car react. However, if you take a new stat and boil it in water and drop it in room temp water it can close in a couple seconds. Age makes them sometimes sluggish.

So, no matter what happens, the temp should not drop below 190 after a power run as the stat should be able to keep up. Likely a sluggish stat.

Last Summer my Lin recorded temp on a long hot run right up to the 220 mark all the time on the road, and in traffic. Tells me the high speed fan was maintaining the temp. Of course that was with 101 outside temp in July.

-chart-

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I don't think a temperature range of 190-210 Deg F is something to worry about. See what happens on a hot day.

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I don't think a temperature range of 190-210 Deg F is something to worry about. See what happens on a hot day.

See pic, this from CarChip recording last July in last stretch to Indianapolis in really hot weather.

Speed on the left side, temp on the right.

Sitting still in traffic makes it top out but well inside the working range. The temp gage did not move more than the width of the hand.

-chart-

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See pic, this from CarChip recording last July in last stretch to Indianapolis in really hot weather.

Speed on the left side, temp on the right.

Sitting still in traffic makes it top out but well inside the working range. The temp gage did not move more than the width of the hand.

-chart-

Could be a slightly sticky or sluggish t-stat, but I don't think there's a problem indicated in the graph.

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Could be a slightly sticky or sluggish t-stat, but I don't think there's a problem indicated in the graph.

That chart on the Lin when it had 47K miles and I think it is perfect performance. For what it is worth, there had been a big storm and there were tree branches and leaves on the road and the speeds were down and variable due to lane changes and road workers clearing the lanes. So not much cruise control on that last hour.

-chart-

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That chart on the Lin when it had 47K miles and I think it is perfect performance. For what it is worth, there had been a big storm and there were tree branches and leaves on the road and the speeds were down and variable due to lane changes and road workers clearing the lanes. So not much cruise control on that last hour.

-chart-

The only thing that stands out is that it takes 5 minutes to drop 10 degrees at 65 MPH (lots of air flow through radiator). Ambient temp would affect this, of course.

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The only thing that stands out is that it takes 5 minutes to drop 10 degrees at 65 MPH (lots of air flow through radiator). Ambient temp would affect this, of course.

" takes 5 minutes to drop 10 degrees at 65 MPH (lots of air flow through radiator). Ambient temp would affect this, of course"

Yea, end of run was 4:15 facing west at 101 degrees. As the sun got square in the windshield the A/C cranked up the blower. In that car, the A/C blower maintaines the temp on low blower in almost any situation except that one. I remember the time as I was supposed to be there at 4:00 but missed a turn due to a map errror.

I did that hot run once before going into Kansas City in the late afternoon but that was ~107 degrees. Begins to push the A/C to the limit to keep 72 degrees. Facing into the sun makes a real difference.

-chart-

-chart-

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Facing the sun adds heat to the cabin and the condenser coil. Max load at that point.

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