Hey guys,
I was at Road Atlanta this weekend in the exocet and previously had noted a small bit of weeping from the water neck - I've replaced the gasket on the (new) water pump twice and now it seems to be leaking even more. 1/2 gallon of water gone a 20 (hard) minute session - problem is it's not pouring out or leaking visibly - it seems to be from both water necks now (you can see spattering on driver and passenger kick panels)?? The only time it starts doing this is HARD (read: on track) driving. I've been street driving/autoX with no visible loss in water. I think my water pump is junk - so buying a new on from FM is on the list, but am I doing something wrong on the gasket install? I triple checked it when I installed it last time and it's still leaking. Is it me or just a E36 M3 water pump? So annoying to have to tear the front of the car off again :(
Where exactly is the water coming from? I'm not sure what you're calling a water neck, especially if there are two of them.
Yeah - that's a terrible way of referring to it. Where the lower radiator hose attached to the water pump and where the return radiator hose attaches to the back of the engine block (re-routed).
Mixing manifold is the name for the water pump inlet, I think. So you're leaking where the lower radiator hose connects there? I'd pull off that manifold and take a good look at the condition of the hose inlet. You sometimes get some corrosion that could cause porosity. Make sure you have a good clamp on there, the factory spring clamps are usually pretty effective but who knows after 30 years. Keep in mind that you'll need a new gasket and probably a new o-ring when you to go reinstall that manifold, both come with a new water pump.
Return radiator hose at the back of the engine block - you mean the heater outlet? I'm not completely sure of your routing here.
In reply to Keith Tanner :
Are you saying that the aluminum neck is going to have porosity or the rubber hose? It does seem to be "weeping" when I can catch it. That is, it's not a pinhole or clear leak point. But with the amount of airflow into the exocet engine bay it's nearly impossible to tell where anything is coming from really....
I'll give you guys a call and order the FM reroute + water pump + new hoses. I don't want to deal with this again and my current reroute is relatively ghetto. Besides the water loss the car ran like a boss and was super fun to drive. The back straight at Road Atlanta was typically (and expectedly) awful for non-super cars in my run group. The gearing with the 13" was also incredibly awful for the front straight - needed a 5th gear shift, but only to downshift into 4 to get up 1. Ah well, I don't go to RA that often anywho - I'd kill to find a 3.63:1 gearset/torsen.
*edit - Apparently I don't need to kill for a 3.63 gearset - looks like I can order on pretty easily....
The aluminum neck can develop some pretty good pitting. I know what you mean about the Exocet blasting the evidence all over the place :)
I've never driven the back straight at Road Atlanta in anything but my V8 Miata on parade/touring laps at the Mitty. Seemed pretty short to me :) Seriously, though, it did seem awfully short. I'd expected much longer given the reputation of that straight. I suspect at race pace that the turn afterwards gets pretty interesting - and that turn on to the front straight must be a puckery ride in a high power/weight car.
In reply to Keith Tanner :
lol - yeah - well from the driver seat of the Exocet, where your helmet is attempting to depart from your head and lifting your arm to do the 4th-5th shift is like fighting against a tornado - it certainly feels like it takes an eternity. We also had a ferrari f430 scuderia, one of those big Benz AMG GT things, Mustang GT350, and a hand full of other nutty cars in our group, so you get the impression you're standing still: you see them as a spec in your mirror - you preemptively point by - and then they're at the esses.... lol
"that turn on to the front straight must be a puckery ride in a high power/weight car."
That turn 11 has SUPERNATURAL levels of grip. You just have to slowly build faith that the grip IS there no matter how bad you want to go slower. My favorite track for giving rides, you can SEE people freak out by their body language as curbing for 11/12 is completely blind going under the bridge. Usually they're having a good time, enjoying the flow, and then you hear the sharp intake of breath when you're still flat/rolling onto throttle going over the hill - once under the second bridge they usually resume breathing.... lol
Did you replace the water pipe o-ring at the mixing manifold when you did your water pump? It's a bit of a chore, and it's possible you chewed the new one up during reassembly. That seems to be a frequent issue.
In reply to ShinnyGroove :
I screwed it up the first time, the second one I think was good, but I'm re-ordering the soft stuff from FM so it comes with a new one. I'll be extra careful on the install this time....
@Keith - HALP - So I'm just a moron - I previously was running a gutted thermostat and I blocked the heater line in my ghetto reroute. This was just supposed to be a stop-gap while I got the car running (which that, at least, I did), but in the interim I forgot what I had done (I know, I know...) and put back in a thermostat when I moved back east - but left the heater pass BLOCKED.
2 Questions:
1) Any idea what kind of damage this might have done? I'm not seeing coolant in the oil - just from the lines themselves. I'm going to do a compression test shortly (have needed to do one for a while anywho)
2) Since I have no heater core, I'm getting mixed signals from searching. Some say just loop it, some say loop it with a restriction since there's no heater core there - what's safe here?
I've ordered the FM reroute, and friends, hopefully I haven't done any lasting damage?
You need it, as that's the primary water path when the thermostat is closed. I'd loop it. I wouldn't add a restriction unless you're experiencing overheating problems - without a restriction, you'll have more coolant bypassing the radiator but Exocets cool well and it may not be an issue.
Keith Tanner said:
You need it, as that's the primary water path when the thermostat is closed. I'd loop it. I wouldn't add a restriction unless you're experiencing overheating problems - without a restriction, you'll have more coolant bypassing the radiator but Exocets cool well and it may not be an issue.
Yeah - I am not fighting the need for it at this point (really I never was, it was always supposed to be a stop-gap until I ordered the real reroute) - more just concerned about damage done - can you theorize any lasting damage I may have done by my boneheaded move of having it blocked WITH a thermostat in place? I ran it pretty hard that way :face-palm: I'm assuming it saw much elevated water pressure while the thermostat was closed and heater pass was blocked....
I can't think of anything. If the water pressure got too high, it would have popped the cap. It might have worked your water pump a little harder, but that basically would have been a loss in horsepower as the engine had to work harder to spin the pump. Your internal water flow might have been interesting, but if you don't see any current signs of a problem then I doubt you have one.
Not that I've done this particular bone-headed move, but having had done a fair bit of them, my recommendation is to not go looking too hard for a problem or you will find one. It will probably be unrelated to the plugged heater line, but you'll certainly find something to drive you nuts :)
Solve problems that you know exist and continue on with your maintenance.
Well, I think this explains the water loss anyway. Thanks for the help guys! Hopefully I really can let sleeping dogs lie...
These are pretty tough motors. If you don’t have any obvious issues, send it and don’t worry about it.
