This is the absolute most frustrating thing ever, I have an 88 rt4wd wagon running a built y7 bottom end and a z6 head with a 50 trim t3/t4. It over heats, ONLY ON THE FREEWAY and only after like 10 minutes ish. I have replaced the radiator with a half size trip core with a fan and shroud, the fan is wired to be on when ignition is on. I put in a new water pump, there's no thermostat, and I have heat when I turn on the blower motor. I am so freaking tired of not being able to take the car on the freeway if you guys have any ideas let me know. Oh also the god damn car only made 235 whp on 17 PSI!! I don't get it I've checked for boost leaks ever thing seems solid all t bolt clamps.

 

Sounds like a HG to me

 

Sounds like the fact that he has no thermostat. Removing it actually causes the water flowing through the engine to NEVER completely cool and bring the engine back to a better operating temperature. Too many people make the mistake of removing it completely, only to lose their headgasket in the end.

Unfortunately, I think you were the cause of your own demise, by both removing the head gasket, and having the fan on all the time, when on the freeway, the flow of air is being hindered by the fan being on all the time.

Use the OEM thermostat, have the fan wired normally, and use the the newer radiator.
This will be done AFTER you replace your headgasket , which I'm quite sure by now has already a few hotspots to be damaged causing further overheating issues.

 

Also the car will cool back down to operating temperature when I get off the freeway even if I'm just sitting there. I only removed the thermostat to see if it was the cause of the problem because it would do the same thing only faster with it installed

 

That was foolish in your thought process. Unfortunately for you, removing that thermostat made a bad situation much worse than the original issue. That means you have a potentially cracked headgasket by allowing cylinder temperatures to spike. You don't have to have spewing white smoke or an overflowing reservoir bottle to see this one coming.

As for what to do about it.. Its actually simple.
1)Please STOP DRIVING THE CAR. Not more "testing", as the damage is already done. 2) REPLACE HEADGASKET WITH AN OEM UNIT.
3) Reinstall Thermostat
4) OEM wiring of Radiator fan switch.
5) Ensure both coolant hoses and thermostat are in good condition.

6) If condition continues after steps 1-5, please replace water pump with a new unit, which may include shimming the pump to allow better water flow.

 

I will do that I also bought a new z6 head just in case. The water pump is a new oem one already

 

So I replaced the head gasket, put the new head on, plugged the fan back in normal and put a thermostat back in bled the system took it for a drive and it still ******* over heats, almost ready to give up on this car

 

Where is the sensor that you're seeing water temperatures located? is it in the stock location or closer to the radiator itself.


Is the OEM "dumb needle" also showing that its running hot or is it just the reading you're seeing?

 

Both the gauge sensor and ect are in the stock locations under the distributor, both are new and I have verified that it is actually overheating through a data logging port in the ecu.

 

Then it may be the radiator itself. I've had that problem before when changing turbo components. You may have suspect radiator. Giving up is of course your option, but that sounds like a "young person's" reaction.

 

The ONLY problem is airflow, your moving air AROUND the radiator not through it. Your being fed a whole lot of BS here nothing ever needed replaced. Build a block off to direct the air through the radiator, and use an OEM fan.

 

Yeah, the HG definitely was not your problem. Also, removing the thermostat will NOT damage anything. Like NA said, you are having airflow issues.

Test this:
Take hood off
Drive on highway

See if it overheats then. If not, then you know you just need to have better underhood heat management. IE: Turbo blanket, better radiator airflow, maybe need a hood vent.

 

This.

OP, I have almost the exact same setup(88 rt wagon, 50trim, a6/z6) and ive had zero cooling issues(had other problems but not coolant related). Only difference is i am using an oem fan. I dont even have the half rad ducted. If your only making 235 @17psi there may be other issues though also. Pm me if you want to talk more.

 

Thermostats are used for a particular reason, and you WILL create a potential hotspot. This isn't an iron block on a Toyota.

We're all trying to help here based upon our own personal experiences, so whatever "BS" one person feels is being delivered, should carry little weight to what you're trying to achieve.

In the end, its not our car. So, please do as you will.

 

Tell us more about your vast experience with shimming water pumps....

 

Ill take off the hood and see what happens

 

THIS AGAIN^^^

I've had two turbo crx both with overheating problems, my current one I had completely torn apart and rebuilt with rods/pistons/planed the head and checked the block new headgasket...still runs hot. I took off the bumper and BAM!!! never runs hotter than 200-205 even after back to back 2nd,3rd gear pulls.

 

Thermostat for sure. Seen this before bunch of times...

 

I don't have vast experience with shimming of water pumps (who truly really does, anyway? that's a rather silly claim of title. ). So, I've never claimed to have that unique skill set.. that's why I said may include shimming, as done on the D-series engines. I'd never shim an OEM B or K series water pump. Simply possibilities, big man.

 

There is nothing to shim. It surprises me that anyone with even a reasonable understanding of how an engine works recommend that someone do so. I'm just an average guy in an average world.

 

Again, I agree.. as I stated now, for the 2nd time.. What argument are your trying to stir up again? you're not making any sense here. Or are you simply trying to create some sort of adversarial atmosphere because.. well, "you can?"

Oh.. that's right.. you're that guy that's gotta have last word on everything. I forgot about that.. Be my guest, have at it, sir.

 

In your last responce you stated it was a possibility, it is not.

I'm just shocked that someone that claims to be a guru doesn't understand simple systems. It's in no way a last word that is important to me, it's the rampant spreading of misinformation that seems to go unchecked.

 

 

I'm sorry man my intent was not to make another person quite so sad. If you need counseling is believe you can find help online.

 

I wana know how you shim a water pump to..

Also how does shimming the pump create more flow??