Thread: Need some help/weird overheating issue. Did research, need expert advice

Ok, So i race 1/4 dirt track. Ran last year with no problems heating issues. Only thing I did was buy a big aluminium radiator. Car would never get hot, even with the fans off. This year I have made multiple changes, And I am having trouble figuring out what is causing the issue. I had already blown 2 tired motors this year. So I freshened the last one I had. News bearing seals, rings, main bearings, and rod bearings. So i finally got to finish a main event. Up to this point no issues at all. When I pulled off after the main this last week, car started boiling water out the overflow. Never got more than 3/4 hot on the stock gauge. So i brought it home, and it continued, every time I would start it it would start boiling water out the overflow before the fans even came on. After searching and searching the forums, I was convinced it was the MLS cometic head gasket leaking and superheating the water. I was running straight water with water wetter. So I pulled the head, had it decked, put in new valve stem seals. So I start it up today, and bam same problem. I had put a new stock head gasket that I had one it. Let me say that last year I ran 50/50 coolant, and a stock de pump. The pump that is on there now is a ve pump I bought from scrildo. I also punched the middle out of the thermostat this year. And I also got a underdrive main pulley, and a water pump pulley. I did try changing the radiator cap back to the stock one as well. It just came out faster. So i have been searching the forums and this is my theory. First it sounds like the ve pump doesnt quite work as well at lower rpms, combine that with the underdrive pulleys, and maybe a slightly to big of a hole in my thermo and boom I boil water at idle. Is that a reasonable assumption? When the car is running at idle like I said it will warm up slightly more than normal, as soon as you drive it at all the temp drops a lot. There were no cracks in the head as far as I know. My plan was to first try a thermo in it again, and then pull the water pump and try the de again. Also , no smoke, car runs better than ever, and the oil is clear. The symptoms are exaclty the same as before I pulled the head, the hoses get all big and huge, and then it starts sptting the water out. The radiator seems to flow just fine as well. It was banged up a bit last year and I had some welding done on it, but it is def not plugged. Really hoping you guys might be able to shed some light on this, and maybe I am right about the ve pump. I am really hoping to not have to pull the head off again. I race on friday and saturday this week so lets hear some ideas! thanks in advance

Use the DE WP.

That simple huh? I'll go change it

Water Pump, SR20, Water pump for the SR20 motor.DE and VVL, but NOT GTI-R.
the DE and sr20 VE are the same waterpump.
sr16ve is different
Me thinks you have a problem somewhere else.

I would start by getting a good gauge so you know what the REAL temp is.The stock one reads 3 temps... cold,normal,or too late !!..LOL
next see what your temps are and then remove the UR WP pulley to see what the difference is.
The UR pulley is designed to help cavitation at high RPM,but the trade off is that its spins slower at idle.
On my VE,I added a gspec WP pulley and immediately noticed a difference in temps at idle.
I am in FL,and at idle the car gets hotter(doesnt overheat but gets hot faster causing the fans to run more.
Driving is fine,and track use is fine.
Stock nx rad.stock thermostat.

I do have VDO gauges and once you have good gauges to compare to the stock,you will see how useless the stock temp gauge really is.
My stock gauge will be at half before the VDO even moves.Then you can watch the temp go up and down as the fans go on and off on the VDO.Its very accurate as far as I can tell.
I ran all day at AMP on the roadcourse,and at least 15 passes back to back in ATL on the dragstrip in almost 100 degree weather with no issues either.

I agree, I need a better temp gauge, last year when I blew headgaskets, both times the stock gauge never moved after the stock radiator failed. So the pump should be the same, Only one I had to compare it to was a cheap one I got off of ebay. Ran the thing 1 time and a fin broke off. The fins are made out of a different material than the ve pump I had. I will try switching the pulley out and see if that helps at all. I was also going to put a thermostat back in it and see what it does. If the pump is turning to slowly, is it possible the symptoms would be so similar to the head gasket leaking vapors into the system? The thing is def building pressure pretty fast. Since I dont really drive it anywhere but the track it is hard to tell what it is going to do. I guess I could try driving it around the neighborhood awhile and see if it overheats when moving. This has been very frustrating, I've pulled the motor and tranny 3 times in the last month alone. And now this issue pops up.

1 more thing, I just went out and started it with the rad cap off. With no thermo, shouldnt the water be flowing? I so see no movement. even when I rev it up. I gt water to splash out 1 time when I really revved on it, but for the most part it looks stagnant. I could be wrong, where the cap sits is kinda off tho the side. I know, i'll go make a video.

Is the pump in there now OEM?

Yes off but it came off a ve, I went out and ran it a bit, the upper hose gets real hot first, the lower hose stayed cool quite a while, and then on the thermo end started heating, but it was still cool at the rad connection on the bottom. The temp gauge showed normal operating tempature, but it sure seems like the motor itself was pretty hot to the touch. I noticed also it started running kinda funny, hesistating when I would rev it up. So I just shut it down. The radiator also started leaking vapor where the welds went bad from this problem. I'm kinda stumped. I think I am going to try the stock rad, stock thermo, and see what it does. If that doesn't change anything, i'll swap the pulley on the wp, and then the water pump itself. Of course the only other pump i have is a cheapie off of ebay, with 1 broken fin

OEM thermostat?