Overheating Still A Problem

[blw]

I have recently rebuilt my son's 1989 Daytona Shelby. As the car type implies it has 2.2 with turbo and intercooler. Since it has the stock intercooler it also has the small style radiator. The overheat problem existed before I rebuilt the engine/car and natuarally I thought this would take care of the overheating problem. The light never really comes on but the gage gets very high and sets about 3/4 to 7/8 over the way to the maximum indication. I live in Dallas so the outside temperature can get to 105 degrees very easily. During the rebuild the following actions were taken regarding the cooling system:
1. Radiator rebuilt and switched to 3 rod system
2. Engine vatted/rebuilt with forged pistons.
3. All engine temp sensors replaced.
4. Engine calibation reset to run at higher boost range to 18-19 pounds.
5. New water pump with new hoses.
6. New heater core.
7. Electronic dash replaced.
8. Head rebuilt with new oversized valves.
9. Replaced thermostat
As you can see I have replaced nearly everything around the block and I am beginning to suspect the block or the entire system is less than optimal. Is there anything else I can do to lower the temperature? Have I left something off the list? Help!!!!

[86Shelby]

Does the radiator fan turn on?

How quickly does it overheat? 2 minutes, 5, 10?

When does it overheat? sitting still? slow town driving? highway? all three?

A/C on or off when it overheats?

Is there anything blocking airflow to the radiator; in front of it?

Do you have access to a scanner to see what the actual temp is through the computer? How about a infrared thermometer or something to check the temp at the thermostat without a scanner.

[mark]

bleed the air from the cooling system?

[JDAWG]

rad cap leaking coolant out? timing?

[MiniMopar]

Does this happen at idle or when driving or both? If it is while driving, the problem is probably the missing airdam under the radiator core support. This is needed to create a vacuum behind the radiator while the car is it motion. The nose of the later Daytonas don't lend themselves well to pushing air from the front and this is a common problem.

If the issue is while the car is standing and the radiator fan does work, then I would look at airflow issues. Is it the original fan or an aftermarket? A lot of the aftermarket fans do not move enough air, partly because they do not shroud the entire core.

[puppet]

Make sure you have the correct year water pump.
You didn't state the t-stats degree range ... in Texas, you'd probably want to be using a 180* stat.
Might want to think about an "always on" radiator fan option. After my '89 warms up to 200* (I think) the cal switches the fan ON and there he stays till the engine is OFF. Makes a good improvement w/'89's cause they are terrible for evacuating underhood heat.
FWIW, I think the T2 radiator .. at 19psi .. is garbage. You can swap in a two row radiator from a V6 with a little work ... but that'll mean moving your IC in the process. Something to consider anyway.
Don't imagine your running a glycol heavy coolant mix in Texas. If you are .. maybe cut back on the Prestone and add in a quarter cup of Dawn (polish water wetter) detergent.

[blw]

Thanks everyone for the responses. I continue to be amazed with the generosity shown by the people supporting this website.

Now to get to work.

Some additional information that will help.
1. The car experiences high temperatures after warming up normally. We see the temperature gauge rise to the high temperature and stay there after highway driving. Of course it gets worse when idling by about one bar.
2. I have checked the temperature with an infrared thermometer and the temperature circuit is reporting accurately. The temperature is indeed high.
3. I have defeated the fan circuit so the fan is "on" all the time. The temperature is high regardless if the air conditioner is on or no. On second thought it my make one bar difference on the gauge.
4. I have replaced the thermostat with several different temperature ranges as well as removing the item all together. No change.
5. I did check the circuit with a scanner and everything seems to be in order.
6. I have run the system with different radiator caps and the current one is new and not leaking.
7. I am running a 50/50 mix of glycol and water.
8. I have reason to believe the model of the water pump is correct since I replaced it and the problem continues.

I think Mark brought up a point worth checking out. Bleeding air from the radiator system. I assumed that filling up the system and coming back to it to top it off after running it would eventually do the trick. In fact I usually do this for 3 cycles before claiming victory. Is there more to it than that?

I also think MiniMopar might be on to something as well. It always was odd to me that the car got very hot while at high speed and we are not steeping on the boost. When I rebuilt the car there were two pieces of material that looked like roofing felt hanging below the radiator connected at various points with plastic push pins. When I got the car it was not in that good of shape and one of these pieces was torn with one half missing and the other was defective as well. I also noticed at a junkyard the other day on a LaBaron Coupe that there was a plastic piece between the passenger fender well and the motor. I would like to find out how many of these various pieces there are so I know what I am up against. Then I need to fabricate/get these parts.

Let me know if you had a suggestion I did not address.

Thanks for all the help guys!!!!

[MiniMopar]

If the fan can't pull the temp down at idle, then something else is amiss. Does the fan look basically stock? With regards to the water pump, what side of the belt does the pump pulley ride on?

[Una]

Yeah, maybe someone swapped the wrong pulley setup onto it.. Running the right pump, but the wrong pulleys on it.. Why on earth they didn't at least change the bolt pattern I don't know...