need some help with ideas my engine was fully rebuilt 8000 ks ago due to water seals,now the car is overheating,mainly under boost the gauge only goes to around 3/4 but its spewing water out the overflow bottle,the engine has no warranty so im wondering what to try,engine builder said change thermostat and radiator caps so we will try that later tonight but was wondering if anyone has had the same problem and what they did about it,the engine is still running fine and isint hard to start so im hoping its not water seals again
any help would be appreciated cheers

 

Stock radiator??

If it is CHANGE IT!! That thing is way to thin for the FD. In 95 degree temps here in Miami I never go overheat.

 

Quite a number of people are tracking FDs with the stock radiator. It really only needs to be replaced when dicoloration or leakage occurs, such as was the case for mine.

Try the thermostat, check your radiator caps, and make sure none of the AST lines are crimped.

 

yeah i am thinking of flushing the standard radiator 2nite as well as it may b partly blocked,i would like to get a custom radiator but there hard to get in new zealand and expensive ,can we use radiator flush in these engines without damaging seals etc
thanks for ideas

 

Ohhh New Zealand ouch!!! Ummm well I would try either way to shoot for the new radiator but all the things Daedel mentioned are worth it too.

 

sinful7 here im just at c,ripples house comparing his radiator to mine,my top tank is quite white compared to his what causes this and what affect does it have,ast lines all seem to be fine along with the other coolant pipes most were replaced with the rebuild
thanks for help

 

The most likely culprits are:

*bad thermostat
*bad radiator cap
*fans are not coming on

 

If your tank is white it may be the effect of coolant seal leaking past the end tanks and boiling off. I saw it on both of my radiators and turned out there was a leak. Another reason is that the coolant temperature is too high, causing the plastic to change color (saw this on a different type of car).

 

cheers but both fans are working, the radiator cap is new with the rebuild as well,we have looked through similar posts but they are all slightly different simptoms spl? my radiator caps are genuine mazda items so how can i tell what pnd they are,the ast cap has a spring on it but the filler housing cap only has a rubber seal is this correct ,otherwise these are all in good condition,will change the thermostat tonight and try that though
thanks
sinful 7--

 

yeah i think this is from my last engine which overheated really badly,so does this radiator need replacing or will it be fine searching for your pics at the moment
sinful7--

 

found the picture of ur block weld experiance,so once the radiator is like that is in bin material or can any flushes get it out
sinful7--

 

bin material

Can't you get PWR radiators, mate? They're made in Australia...

 

hm never heard of them ill have to do some reasearch thanks for that, you dont have a link to the site or prices that would be great cheers
sinful7--

 

I just had the same problem 2 weeks ago. You are correct about the ast cap having the spring and the filler cap having the rubber seal. I replaced both caps, thermostat, water thermo switch and radiator.

 

I recently had my motor rebuilt and had the stock radiator put back in. My car ran really hot as son 100-121 C as I got it. I was running evans coolant, so it never boiled over. I ended up swapping out the stock radiator for a Koyo after a few weeks. Now my temps are a consistent 85 C...at zero psi

The engine sealer may have partially clogged up your radiator after the rebuild. I read somewhere where someone on this forum had a fluidyne cut open and inspected. Sure enough, it was all gunked up with sealant.

 

ok guys cheers for your help sounds like the radiator is the problem i will change the thermostat tonight and we are searching the net for replacement radiators thanks for all your help
sinful7--

 

Radiator is soooo worth it. Remember once you run more HP your going to start getting hotter. Its worth it in the long run.

 

I changed the thermostat then went out for a long test drive, and everything seems to be good, no overheating and no coolant spewing out of the overflow bottle.

I have emailed few places in New Zealand that does custom radiators and just wondering what would you US guys recommand on the thickness of the radiator(how many rows)?
For a 56 mil 4 row polished aluminium radiator I'm looking around NZD $1200 thats about USD $760.

But I think this 4 row radiator might be too big(thick), so could someone tell me on your aftermarket radiator how many rows it has.

Thanks.

 

Check the Rx7 store and see what the specification are on those. That price is a tad high but I guesse a good price none the less in New Zealand.

 

I know that price is a bit on the high side, but if I could get away with say like a 2 row radiator then the cost would be a lot cheaper.
I will have a look at the RX7 store and see if I could find some specifications.

Thanks

 

OH, No. Well I thought my car was okay with the new thermostat, and the temp guage went up to 3/4 again but this time coolant isn't spewing out of the overflow bottle!! So this is gotta be my radiator that's causing the overheating.

I had a look at the RX7 store but I couldn't find any specifications on the Fluidyne or Koyo radiators.

So what I need to find out is how many rows your Fluidyne or Koyo has or whats recomended.

Thanks heaps
Sinful7--

 

Just ran down to the basement to check. My Koyo appears to have 2 rows (each about 1.3-1.5 cm wide). They are made in Japan, so you should be able to get them.

 

Sinful I suggest you get the radiator ASAP dont want to kill the O-Ring =/