WILLSMAZDARX7

it hasn't overheated completly but it keeps running hot
this is whats done , all emmissions removed no cats
i put in a new thermostat ( not stant) but actualy pulled out of my 90 gxl motor
that ran perfect i put in a new water pump i checked the timing
i'm not sure what the hell i'm missing i'm dumb founded
the car starts every time runs fine seems to idle ok

what else could it be?

gray_86

did you bleed the system get all the air out of the tubes

WILLSMAZDARX7

i'm sure i did but it's hard to figure out when it's all done any suggestions ?

Archangels

sounds like an air pocket in your coolant system....

SureShot

Sureshot’s Overheating – check list
1) Replace the thermostat. Make sure it fits. The spring loaded disc under the stat valve must close the bypass port, or guess what? –You get symptoms like a blocked radiator.
2) Replace the radiator cap. Low pressure = steam bubbles = spit out coolant.
3) Look for leaks. (same symptoms as #2) Some can be very hard to find. You may have to pressure test it. A common failure spot is the 3/8” coolant line that runs from the top of the rear housing (under the intake runners) to the throttle body, to the BAC, to the water pump. Another one is the heater hose under the oil filter.
4) The fan clutch will slowly start slipping as it ages. The fan should pull really hard up to about 3k when the motor is hot. It should maintain about 3k as the motor revs higher. Sometimes you can get more life from it by bending outward the bi-metal strip on the front of the fan clutch. The cut-in for the series 4 fan clutch is gradual – it pulls some even when cold. The series 5 fan clutch is more on/off. If your fan only revs to 2K, the clutch is worn out.
5) The rotary engine gets almost half its cooling from the oil. The oil cooler is as important as the radiator. Make sure it’s not blocked with leaves or road debris.
6) Is the oil cooler thermostat working? When the rad is warm, the oil cooler should be warm also.
7) Are the stock top covers & front undertray in place?
Banzaitoyota’s checklist
1.Are the Oil Cooler fins clear of debris and clean?
2.Does the Oil Cooler thermostat function properly?
3.Are the Radiator Fins clean of debris?
4.Is the stock front undertray still in place?
5.Are you running a Dual Belt Pulley on the Alt?
6.Did you install a NEW Water Pump when you installed the engine?
7.Is the bottom hose collapsing under load?
8.Did you have the Radiator and Oil Cooler cleaned and Flushed when installing the rebuild ( AS required by MOST REPUTABLE REBUILDERS)?
9. Have you verified water temps with a real gauge instead of the sock POS?
10. What ratio Coolant to Water are you running?
11. Are you running a new STOCK MAZDA OEM thermostat?
12. Mazda Rad Caps?
13. Stock Fan Shroud installed ( For those of you running stock Mechanical Fan)
14. Electric Fan users: Do you have a Shroud installed at all. Most installations only draw air directly across ~60% of the available core surface area.
15. are the stock deflectors installed around the relays forward of the Radiator Core Support?
16. If 15 is a no: Do you have an plate mounted across the support to direct air-flow?
17. Install a spring in the lower rad hose to keep it from collapsing at high RPM

My5ABaby

iTrader: (7)

So how long have you been waiting to post that?

SureShot

It usually gets posted about once every 6 months.

I have my own little FAQ doc to copy from.

My5ABaby

iTrader: (7)

Me too . I've recently started compiling information (I get REALLY bored at work).

WILLSMAZDARX7

thank you guys for the help i have check alot of items on the list but i will print that list and go one by one untill it's fixed thanks again

Sgt. Pepper

Does the stock undertray help with cooling? I just took mine off to do a coolant flush and left it off since I didn't have enough time to put it back on. The undertray seems like it restricts air flow to the oil cooler/radiator since now the only way for air to get in is through the front grill, and not from underneat the car too.

Tape.Worm

Do a block test. That way you can see if your fucked or not right off the bat. If the bubbles keep coming and you can't get all of them out chances are that you just blew a coolant seal and your getting exhaust in your coolant...(sounds like your on the way there)...

My5ABaby

iTrader: (7)

Air follows paths of least resistance. When it comes in contact with the front of your car, the easiest way to go is around your radiator instead of into it. The undertray forces that air into the radiator.

Some people get by without them, I did for a while. I didn't have one at the time. But, I would suggest putting it back on if you have it.

SureShot

This is not a problem with high nose & vertical radiator setups like most cars.
On the RX-7 with its low nose, front air dam & slanted radiators, it matters.
Without the front bottom tray, air comming through the grill can dump in front of the radiators wthout getting forced through them.