new owner 1990 zr1
 

Hi having cooling problem!! temp almost pinned 2/3 and fans are working but radiator is a mess.started pulling shroud out and going to continue today,somebody mentioned the (high press by pass valve) is this a concern and where is it.thanks for any help!!!

Re: new owner 1990 zr1
 

try first pulling the radiator out and cleaning out all the cooling fins .our cars are hoovers picking up all sorts of things . that should solve your cooling issues.. you might also get on mark haibecks site for other cooling solutions .sorry don't know how to do the link thingy

Re: new owner 1990 zr1
 

if your rad is blocked that's going to hurt your temps, clean that and get an aftermarket chip. I suggest mark haibeck at www.zr1specialist.com. as for the by pass valve, over 5800 rpm the rad can't handle the flow of coolant so it bypasses the rad and goes back into the block causing temp to go up. Found this out the hard way, I was playing around in second gear one day, looked down and almost **** my pants. If you swap the rad for an aftermarket one you can get rid of this "feature"

Re: new owner 1990 zr1
 

Thanks guys started shroud and met up with the three on drivers side and realized my small ratched was not in tool box,thanks again cant wait to see this radiator.

Re: new owner 1990 zr1
 

Here is a link to Marc's website section on a clogged radiator. I had this problem on my 93 and had to remove it and hose it out. ---Bob
http://www.zr1specialist.com/HAT%20W...o/radiator.htm

Re: new owner 1990 zr1
 

BTW, at high revs, you don't stop flow through the radiator, you just run excess flow around it.

Re: new owner 1990 zr1
 

Thanks cant wait to get home.

Re: new owner 1990 zr1
 

HELP !!!!!! SHROUD LOOSE WHATS THE TRICK FOR GETTING IT OUT?

Re: new owner 1990 zr1
 

I had the same issue. Took it to Marc's for some other work and had him pull and clean radiator. It was nasty - even with 18k miles on the car. 1/3 of it was covered in oil from oil cooler lines that had leaked at one time - which attracted all kinds of dust, vegetation, and fuzzy junk. The rest wasn't as bad - but it still had a lot o junk in it. He used like 2 cans of brake clean just to get the oil out (so you know what to expect). If your car doesn't have a debris screen on it you can make one pretty easy. http://www.zr1.net/forum/showthread.php?t=20178
I also went with Marc's chip - and between the cleaning and the chip I went from running 200 on the road and 230+ in traffic - to about 180 on the road and 210 in traffic...

The shroud takes some wiggling to get off there - I didn't do it but I watched Marc and it takes some careful wiggling and lifting...

Re: new owner 1990 zr1
 

Ill get it just looking for some tips haha!!thanks