Overheating still

[BeatDaSHO]

Well, I will give you my story. So last summer, everything was great with my car. When it would heat up, the gauge would read between the A and the L. It has always read there. Well, in August last summer, the temp rose to the N. The fan would then come on but would only lower the temp to the O. It would then rise right back up to the N, sometimes past the N. This wasn't right. I replaced the thermostat with the motorcraft one. Still rose up to the N. Then i replaced that thermostat with a Napa 180 degree one. (They always run cold). Still rose up to the N. I replaced the gauge sender. Nope, still rose up to the N. I then decided to replace everything in the cooling system. New ECT, New radiator, new lower radiator hose, 4 different thermostats, IRCM, water pump, and 2 different senders. I got a leak down test to make sure it wasn't a head gasket and it wasn't leaking anything. I hooked up an aftermarket water temp gauge and it was indeed going way too high. About 220 degrees. (This isn't "overheating" but it is about 35-40 degrees difference from what it should be). I then put an aftermarket fan relay which kicks the fan on whenever I want it to. This has kept the temperature down to 195 which is still about 15 degrees off from normal. The fan is always kicking on. I decided to try and keep the fan always on but the temp still rose right up to 195. It doens't matter how fast I drive, the temp will go to 195. All of the reflectors for air are intact. (The wheel splash gaurd, the under radiator plastic piece.) I have driven my car for one full year now with it like this. My car runs like a champ except for this overheating deal. I take very good care of my car and fix anything that goes wrong with it. But I haven't been able to fix this. What else can I do for my car? I am sick of having the fan always kicking on with this relay. I just want it fixed. If people have some ideas, I am willing to reward them if they are correct in finding the problem. Please help me out. Thanks.

Greg

<small>[ July 10, 2003, 07:45 AM: Message edited by: BeatDaSHO ]</small>

 

[twr]

The larger of the 3 hoses that comes out of the bottom of the TB is for the PVC system, unrelated to the cooling system. You replaced the lower radiator hose, what about the upper one??

Did you happen to do any modifications to the car before the over heat problem started??

<small>[ July 09, 2003, 05:23 PM: Message edited by: twr ]</small>

 

[TYSHO]

Have you tried flushing out the coolant system?

 

[BeatDaSHO]

Yes, I forgot to mention. I have flushed the system about 4 times now. I got that Prestone flush kit where you make that T into the heater core lines coming out of the firewall. Nothing changed.

Damn, I forgot that the hose under the throttle body was for the PCV. I forgot all about that. My bad. Nevermind then.

I didn't do any modifications when this happened. I was just driving one day and it heated up to 220 degrees.

Greg

<small>[ July 10, 2003, 07:46 AM: Message edited by: BeatDaSHO ]</small>

 

[projectSHO89]

First off, normal operating temp is around 210 or so, not 180.

220 is not a real problem and is well within the operating parameters of the engine.

Steve

 

[BeatDaSHO]

220 is a problem. As all Gen 1's run between the A and the L. Mine runs up past the N and power is lost when it heats up that high. The car also pings more when up that high. 220 might not be harmful for the engine, but it isn't right. My brother owns three other 89's and they all run between the A and the L which is about 180-185. Mine used to run like this until this all happened.

Greg

 

[JoeHoe_SHO]

Its a good thing you have that police grill rep. Your car would be running hotter(is that a word?) if you had the stock bull nose grill. New radiator time maybe? Need one let me know

 

[TYSHO]

Well my Gen. I runs between the M and A and goes up to the O before going back down after the fan kicks in. It probaly needs a good flush too.

PCV? Are you saying you put the coolant flush in your lower TB PCV hose? shrug

 

[BeatDaSHO]

That PCV post was about something else. It was worded wrong. Nevermind on that. Your fan kicks the temp down to the M and the A. If I hook up the fan back to the way it orginally was, my car will rise up past the N, the fan will then kick on and cool it down back to the N. Not good.

Greg

 

[TYSHO]

Have you tried replacing the motor type deal that controls the needle reading? On the 89 it has it's seperate one and as for the tach and can be replaced. My tach was acting funny and I replaced it and now it works correctly, maybe this is happening to yours, but on the coolant temp needle. shrug

 

[BeatDaSHO]

That is why I got the aftermarket temp gauge. Tomorrow I think i'm going to try and take out the thermostat and see if it still heats up. If it does, then different things can be ruled out as to why this is happening. We shall see. Any other suggestions? Please help.

Greg

 

[jasonty]

Have you tried pressure reverse flushing the coolant system? Most shops have the capability to reverse flush coolant systems with pressure, or you could try this with a garden hose. By doing this, you will remove the scale buildup in the water jackets. If you just flush the coolant system in the same direction in which coolant normally flows, you are just flowing past that scale buildup, maybe eliminating a small amount of it if you're using an additive such as Prestone. Reverse flushing from the radiator hose opposite of the thermostat housing goes the opposite direction of normal coolant flow, and the pressurized water will hit the "lip" of the buildup, and push it out. If you have replaced all of the cooling system components as you described, I'm thinking you have a water jacket with a restriction in it that is slowing down the flow of coolant. Reverse flush it, and if that doesn't do the trick, check the condensor in front of the radiator and make sure it's free of debris. You don't have to pull your thermostat to see if it's working. Here's how to check it. Pull the cap off of your radiator, start the car up, and watch the water inside of the radiator. When the water starts swirling, your thermostat has opened up. Another trick that we use a lot down here in TX, is pull out the thermostat, and with a pair of *****, cut out the wax pellet assembly, and re-install the thermostat skeleton. Re-installing the skeleton slows down coolant flow to the necessary amount to achieve proper engine cooling. Coolant that flows too fast won't absorb heat and do it's job, but coolant that flows too slow won't dissipate heat to the radiator fast enough. By the way, when you reverse flush, it might be a good idea to remove your thermostat. Hope all this crap helps!

<small>[ July 10, 2003, 09:07 PM: Message edited by: jasonty ]</small>

 

[BeatDaSHO]

Thank you very much for that long write up. I really appreciate that. I installed that prestone flush kit where it puts a T into the right heater core line. Then you hook up a garden hose to that. Isn't that back flushing it from there? I never tried the prestone additive stuff for flushing. Maybe i should try that. What exact hose would back flush it if the right heater core line doesn't? Thanks boss.

Greg

 

[TYSHO]

I think he said the opposite side from the T-stat, so I'd assume the lower radiator hose.

BTW- Why is it that everytime I'm in this thread things tent to run a **** of a lot slower and when I type my reply it won't show up until I take a pause? All I can see is the marker moving and no letters until I pause/stop typing, then it comes up slowly. Same as when I scroll the list of reply's and once I push one direction it won't stop. shrug

 

[AutoSHO]

A "Reverse-Flush" would be forcing water in the thermostat side, and out the water pump, the opposite of normal flow.


And the reason this thread is slow is because BeatDaSho's animated avatar slows down some computers. Fortunately, 2.8 Ghz took care of that for me. shrug

<small>[ July 11, 2003, 04:15 AM: Message edited by: AutoSHO ]</small>

 

[BeatDaSHO]

Oops. Sorry about that. I changed it.

Greg

 

[BeatDaSHO]

Well, today I decided to flush the system again. I took out the T-stat and sprayed inside the engine block with a garden hose. I pulled off the lower radiator hose and let it flush through for a couple of minutes. To see if the upper radiator hose was collapsing, I put the hose in a boiling *** of water. It did not collapse so that isn't the problem. I put everything together but I left out the t-stat. I used the prestone flushing kit where you hook up your garden hose to the heater core line. I flushed it for a good 10 mins with the car running and the heat blasting. I turned off the water and went for a drive. Now, the t-stat is NOT in the car anymore. The car would heat up to around 190 and would fluctuate between 180 and 190 while driving. The temp would not go over 190 so the fan relay never kicked on the fan because that is set for 195. So now what? I thought without the T-stat, your temperature would not get like above 150 or so. I thought your car would stay in closed loop. Hmmmm......any ideas??

Greg

 

[BeatDaSHO]

*bump*

 

[BeatDaSHO]

Well I kept on testing the car with the thermostat out and it seems as though the car doesn't get above about 170 so i figure this is a little too low. With some highway driving, it will drop to around 160 so this is too low and will soon ruin my cats. So i put the T-stat back in and now i'm back to square one. It still heats up to 220 which is around the N before the fan will kick on and will only lower it to 215. Any other suggestions?

Greg

 

[Slo-Sho]

Just out of curiousity, where did you place the sending unit for the aftermarket gauge?