cooling problem
 

i got an 87 rx7 with a 89 turbo engine swap done, haven't had any issues til lately for some reason the engine temp. keeps getting around the 3/4 mark on the gauge when it use to run at the lower 1/4 and it keeps filling my over flow jug up, ive replaced the cap flushed the system and replaced the thermostat with a direct "oem fit" and found no combustion gasses in the coolant, i have no bubbles and no smoke so i dont know what else could cause it or if its just the way its going to be, debating on just putting a lower temp thermostat in it. anyone ran into this problem before? ive searched but most people have the typical blown seals symptoms but noone seems to have this issue that i have found so far. any help is greatly appreciated

I used to have this problem, it was a bad water pump. it was not leaking or showing any exterior issues, but the blades where all mangled when i pulled it out. Also had a oiler cooler that was plugged.

Do you have an electric fan installed? If so, is it pushing or pulling? I once saw a similar case to what you are describing. The mechanical fan was replaced with an electric one, however the fan was set to push instead of pull. Once the fan was set to pull, the problem went away!

Now with that said, the best way to know if you have coolant seal problems is by doing a pressure test on the system. Looking for champagne bubbles does not shows up when the coolant seals are barely starting to fail (at least in my experience)

i just put an electric fan on because the clutch one went out and no one around here sales a replacement but the coolant in the radiator is not getting hot enough to kick the fan on but the block is getting plenty hot, i will pull my water pump and see if its ok. thanks for the help i will update later

oh and it will have pressure on it the next day after i shut it off as well, so i'm figuring the system is sealed but not 100 percent

Sounds like a stuck thermostat or a block somewhere in the system if the radiator is cold and block is hot. You'll be able to see if when you pull the water pump.

i flushed it and it didn't help, water pump is all good so i took my original thermostat guts out and put it in now it acts right fan kicks on and everything so i guess i had another bad thermostat.

Post pics of what your setup looks like.

To me,I am thinking that you are running without any rad shroud for the fans.,

https://cimg0.ibsrv.net/gimg/www.rx7...8a90d678cf.jpg


https://cimg3.ibsrv.net/gimg/www.rx7...6106c9a762.jpg

theres my setup, what do you think?

update. i got it to stay cool, i had to make a skid plate but now it stays cool, but i was checking for leaks again because i had just replaced my heater core and wanted to make sure everything was ok, i fixed all leaks and decided for giggles id take my plugs out and turn the motor over by hand and check for coolant again and with a big chug a big sploosh of coolant came out of the front housing only, so im guessing the only way coolant can get there is through a slightly blown coolant seal, it doesnt smoke while i drove, just on cold starts in the morning but it has started putting more coolant in my overflow, so only fix is to go into the engine correct? i dont have any coolant in my throttle body or intercooler so that rules out turbo seal sadly

New coolant seals and likely an iron required, at a minimum.

why an iron?

The o-ring land is often corroded and cracked when the break in the seal is.

oh ok im guessing it will be obvious if thats the case?

when you clean the groves if it's cracked you'll see it.. if it's missing it would be hard to miss

ok thanks for the info. i hope thats not the case. what will happen if i keep driving it with the seep?

Well you were right. It did cause damage i finally pulled it apart. Ill need a new front side housing. But i was wondering is this acceptable on the rotor housings. They both have to spots like that



https://cimg9.ibsrv.net/gimg/www.rx7...5a2f982a76.jpg



https://cimg2.ibsrv.net/gimg/www.rx7...7520baef09.jpg

Also heres the front iron
https://cimg1.ibsrv.net/gimg/www.rx7...5ac04c64df.jpg




https://cimg3.ibsrv.net/gimg/www.rx7...845b2f4599.jpg

C. ludwig told you it was broken, i just told you that you would see it.

yes you was right, but the rotor housings have those black pitting on the edge, is that ok? or do i need to get new ones

Nevermind i found the spec for it. Its less than 2mm so its ok