Begi coolant reroute...entirely too cold.
 

I have the basic reroute from begi. The one that takes the heatercore outlet and brings it back around to tee into the upper rad hose. In the instructions begi notes that the car may take a bit longer to get up to temp. It's not a bit longer, it's a LOT longer, and it's never quite as hot as it ought be.

My N/A 99 gets up to temp in about two minutes, the turbo 91 with the reroute takes about 18-20, and that's WITH driving about 55mph at 3k rpm, if I just let it idle it would take longer to get to temp. I thought it might be the thermostat, but I changed it for an OEM and it made no difference at all. The radiator is an all metal dual core, but it was on the car before the reroute and there was no problem with the length of warm up time when it went in. There is a big cx racing intercooler taking up the whole mouth of the bumper so it's not too much airflow. Takes forever at idle with no airflow as well.

The fans never come on at all, and the gauge "up to temp" almost looks to be a little lower than it was before the reroute, like ten oclock or so. Sometimes it even drops a bit after getting there. I doubt its the sender, a friends went on his 97 and it resulted in wild movements of the needle. Mine just takes forever to come up.

The only solution I can think of is a thermostat housing plus a stat on the line that goes from the heatercore outlet to the upper rad hose tee. but that would leave the water nowhere to go - it would hit that stat and just sit there until it opened, which might build up the pressure or something. Not sure what I can do at this point other than take the reroute off - the car literally cannot be used safely as it is. It's just coming up to temp at the end of my 20minute commute in to work, or coming home from work. I never even get to use boost.

Any ideas? :vash:

yes, move that TEE to the lower radiator hose.

X2 Mine was the same way and the changer to the lower hose solved it.

thanks guys! - does anyone know the ID of the radiator hoses? rather than ordering another upper rad hose, might just use a piece of pipe. It's a new hose, finishline doesn't sell them seperately. Sick of ordering parts anyhow.

Moving the tee to the lower hose is identical in function to the original setup, where the water from the heater core went back into the mixing manifold via the hardline which ran across the block below the exhaust manifold.

Here's an idea for solving the problem entirely- it'll cost a bit of money, but should provide the best of both worlds. Use a remote oil thermostat to control where the water from the heater core goes. I believe it could be installed in such a way that water coming in from the heater core is bypassed to the lower radiator hose when cold, and diverted to the upper radiator hose when warm.

So the solution is to remove the hardline that returns to the mixing manifold and hook it not into the upper radiator hose, but to the lower radiator hose that goes to... The mixing manifold. Slightly disingenuous....

Well, it works when it's warm. So I'll give them the benefit of the doubt and say in Texas it doesn't get cold enough for them to have experienced the problem. They should change the manual though.

I'd go completely back to stock except I cut the metal tube under the headers/manifold so that I didn't have to mount it with the turbo manifold, which was going to be a pain, and seemed likely to heat the tube, and maybe bake the piece of hose begi provided for the plug, causing failure and coolant dump. So I cut it. It terminates with the begi supplied plug about an inch off the waterpump.

The stat you linked to looks like it would work, I'd need another pipe to tee into the lower hose.

So my options are, make the oil stat work, who knows how much time or money, tee into the lower hose ($30 for new upper rad hose) , or go back to stock with a new water tube ($20), new upper hose (35) and another set of heatercore hoses ($25).

I guess I'll tee it into the lower, since that is the cheapest option and doesn't involve fumbling around under the turbo. Sucks that I have to do anything. I've already had to to purchase another thermostat (25 shipped) and do a full system flush with that, for the cost of the coolant, which I will have to do again to tee into the lower. Sweet.

Basically this reroute is a crappy design, and probably shouldn't even be sold. Maybe it works in Texas.

Yeap, it's pretty much pointless. Better would be to build a setup that mimics a FWD BP 1.8. IE freeze plug in front of engine and a rear mounted thermostat. That might actually do something.

If I were you I'd put it back to stock and sell the begi stuff. Then do a real reroute one day.

yeah I probably could sell it. But I wouldn't want to inflict it on anyone.

Actually both the concept and design serve their perpose well. The problem is that you are using a sledgehammer to drive a nail. Were you having cooling issues before you put this on? The combination of both a dual core raditor and the re route will keep your car at a safe temp under even track conditions. If you aren't running it at a track then you obviously don't need to cool it that much. If you were getting a little hot then trying some water wetter may have done the trick for you. I have the begi reroute on my 2.0l and i use a 55mm PWR radiator at the track and a stock raditor on the street because i can't get it to optimum temp. The reroute works great for those who need it, especially here in texas.

I had this same reroute with a stock radiator and could not get coolant temps above 140F while the car was moving when the ambient temp was below 50F.

john - but it does get up to temp, and fast enough, when tee'd into the lower hose? With an OEM or an upgraded raddy? I don't want to tee the lower if it's not going to help. I just ordered an upper hose from moss, $20 shipped was cheaper than getting the kit of upper and lower hoses from finishline.

It's completely like stock when tee'd into the lower hose for me with my stock rad. I believe some people have had to block off part of their thicker rads in order to run at operating temps during the winter. I know Paul does, but he also has a true coolant reroute so that's not a perfect example.

Where's the ecu get it's data from? My hydra will show steady temps, but the dash gauge will be moving all over the cold portion. This has only happened since I did the reroute.

on the 1.8 NA it's over under the cas a little bit. not sure where it is on the 1.6

All NB's have a dual purpose temp sensor. It has two outputs. One for the ECU, one for the gauge. Where the older 1.8's and 1.6's had two separate ones.

i did my reroute dramatically different from the BEGi idea. I used a stock t-state housing cap on the back of the motor with the JR spacer, machined for the t-state and heater port.

The heater return goes to the radiator return.

Cool water goes from the radiator to the water pump...with no mixing. Do I need some mixing action? I thought it would be better to not have warm water mixed with cold...if I'm tring to kep the car old.

Did I screw up?

"The heater return goes to the radiator return. " sounds like mixing to me


edit: was thinking in terms of returning FROM the radiator, not TO

It does work when warm and cold here. In the mornings we occasionally get down to 30 degrees F. It takes about 6 miles to reach operating temps. In warmer weather, it takes about 4 miles to reach operating temps.

However, not everyone is in Texas, so we do have an alternative part available if needed. If you already have the water bypass system (new lower radiator hose) all you need to do is replace the straight piece of metal tubing with one that has a hose barb on it. Move the coolant line from the upper radiator hose to the lower radiator hose. The part will cost $25.00 and is a direct replacement for what is already there. You will need to go to a hardware store and get a plug for the upper radiator hose.
Stephanie