Crackership

This has been happening for a while now, and it's starting to really confuse me. It doesn't do it every time, but pretty often. Here's what it's doing:

Drive car
Park car
Somewhere between 1/4 and 1/2 cup of coolant pours out of the overflow in the fill neck of the expansion tank.

I've replaced my radiator cap, cause I thought maybe the spring was getting weak or the seal wasn't sealing well.

I've pressure tested my coolant system and it holds

The only other oddness that seems like it *might* be related is that my car tends to run on the cooler side... right around the bottom one of the middle two tic marks on the gauge....

Nothing else seems wrong with the car, but I'm pretty sure it's not supposed to have a wee after being driven...

Any ideas?

TIA!

hp18racer

Most likely head gasket. Combustion pressure pressurizing coolant.

Crackership

I had this idea, but dismissed it after doing the pressure test... I would think a head gasket issue would have been obvious with the system pressurized. Correct me if I'm wrong...

mtnman82

I've been going through the same thing and have a thread asking the same question, with good advice on things to look at/try. In the end I just recently concluded it is indeed the head gasket. I came to this conclusion becasue after running around for an hour or so one evening, I went to drive it in to work the next morning but upon starting it was only running on three. I came home at lunch to pull the plugs and found one of the plugs wet with coolant. I pressure tested too and everything seemed fine. Try letting it sit overnight after running it, then pull the plugs. If you don't see anything on the plugs, try to stick a long cotton swab down in there to see if it picks up anything.

FWIW, I had the same symptoms on my truck a couple years ago and went through the same procedure (letting it sit overnight then pulling the plugs). In that case I had my son crank the engine with the plugs out and saw water spitting from one of the cylinders. The truck pressure tested fine and I also did the gas test from the radiator, btoth of which were fine. These headgasket issues can be tricky, as I've come to find out.

My big worry now is that I f'ed up the cylinder bore from having run this way for what I'm thinking now has been several thousand miles. I remember the radiator cap popping off once when I was getting on it with the boost cranked to ~18 psi back a while ago, but thought I had just forgot to tighten the cap properly and the cap never popped off again. Then the coolant spewing started, and here we are... If I did indeed f-up the cylinder, I guess I'll be building a 'blown' stroker sooner rather than later.

Crackership

Well.... Lame

mtnman82

??? - my post is lame???

lart951

Greg, not your post, lame that it is the hg and the whole concept of replacing it. anyway I have a question for you and crackedship, are you guys running any wide band sensor?

KevinGross

If the car is not pushing coolant until parked (check the reservoir), your problem is the radiator fans not working. Which is usually bc the temp switch in the radiator is bad, but could be due to the relay, wiring, etc.

If it's pushing coolant when driven, probably the head gasket. Get a block checker kit which detects exhaust gas in the coolant.

Crackership

Greg, Lart beat me to it, but I just wanted to make sure it's crystal clear: Your post was great, and very helpful, and I greatly appreciate it. My comment was just in response to the likelihood of having a blown HG and all the "fun" involved in replacing it. Very sorry for the confusion, I meant absolutely no disrespect.

Lart, thanks for jumping in to clear that up! It's much appreciated.

I am running a Zeitronix Zt-2 with Wideband O2. Are you thinking this would indicate a blown HG in some way?

Kevin, I will keep a closer eye on the operation of the fans and check coolant levels immediately after a drive to be sure that it's not pushing it out while driving, but I'm pretty sure it's not.

I know that my fans run sometimes after a drive, but not all the time... I hadn't really thought anything of it, and so I haven't noticed if the coolant being pushed out is only happening when they're not coming on. Thanks for the input! I'd definitely rather swap the sensor in the radiator than replace the HG

mtnman82

No worries Dave, just wanting to make sure I wasn't overlooking something or going about things wrong.

Luis - I have a ZT-2, but it's not in yet. I know - really one of the first things I should have done. I bought the car with Guru chips that were supposed to be 18 psi chips, but haven't run those in a while. I went to Vitesse software (AFM & MAF) fairly quickly becasue the Guru stuff was very doggy and I could tell it was a tuning thing. I've only run @18 psi a few times, it's spent most of it's days with me @15 psi. I've got the Rogue AFM software in there now and really like it based on the ~hour I actually got to drive on it.

My fans are working when I park the car (if it's hot enough) and I replaced the thermo switch when I replaced the radiator just before the spewing started. Actually, I'm thinking it's been spewing longer than I knew and I just wasn't really paying attention to it - I remember coming out of work a few times and seeing a puddle of water under the car and not really thinking about it. I'm thinking the excessive pressure is what blew the original radiator now. Coolant on the plug is what it is. I've been running straight distilled water so hopefully that helped not to f things up(?).

I got taken in a big way when I bought this car. I should have researched and read more on this forum before jumping into this world, but I didn't even know this forum existed until after I bought and I had a small window of opportunity for even being able to get one of these cars (I've wanted since they first came out) and so jumped at the chance. Basically everything that could be wrong mechanically has shown it's ugly head over the years: major engine leakage and had to reseal, bad clutch from the get-go, lots of little things like the sunroof gears/motor, and I'm sure the headgasket was on it's way out from day one. I'm absolutely positive the previous owner was absolutely aware of all this and was just very dishonest in our dealing. My bad, but I'm hoping karma catches up with him eventually. Wifey's been upset (pissed) from day one, as I was supposed to be buying a car that was in nice drivable condition as opposed to the Z-car project I gave up to buy this. The paint/body/interior are in exceptional condition, but I've seen just as nice come along for less than I paid. I really believe when I get the headgasket replaced I'll actually be able to consistantly drive it for a while (knock on wood). Hopefully this is the case, as I'd love to be driving it while taking my time to build up one of those stroker's.

Crackership

Sorry to hear about your luck... I've actually had almost that exact issue with my ex-girlfriend... Honestly, I really think the 951 played a pretty big role in her becoming my ex... Ah well, life goes on, and if I could only keep one of them...

On the bright side, you can always tell her that, before too awful long, you will have replaced every part there is on it, and then it shouldn't need anything for good while. I'm not totally sure that logic holds, but it sounds good.

I'm still not completely convinced my issue is a HG, but it may well be... I'll be in the general vicinity of the HG in the near future with some other work I'm planning, so I'll replace it as a good measure. I'll definitely post my findings.

Thanks!

ehall

Definitely not always the case. I had precisely the same symptoms with great fan function, switches etc. It IS however the very common symptom set of a slightly blown HG on a 944 turbo. Mine was so slight that I couldn't I.D. it, after removing the head. I sent a couple of pics to Chris White and he I.D.'d it for me very quickly.
I went through every conceivable coolant trouble shooting idea, mostly because I was REALLY hoping it wasn't the HG.

All that said, a HG replacement isn't really all that difficult. It get's expensive when you add up all the "While I'm in there" stuff that you will probably want to do.

Sorry for your loss Cracker. SUX!

ehall

Have faith. Once you get the mechanicals solid, you'll have a damned solid and reliable car, as long as you don't treat it like crap or ride it hard and put it away wet. There's hardly any need for more than 15 psi, on the street, or 18 if you want to feel naughty. After that, all bets are off.

Crackership

Well.. Under Kevin's advisement, I drove the car, parked it and immediately popped the hood to see if I was loosing any coolant out of the reservoir while driving, and I was presented with a solution to my issue (I think)... There's an F-ing crack in my reservoir! It's small, but it's there and coolant was squirting out of it. . I guess I need a new one...

Crackership

Any ideas on how to seal it up temporarily? I'll hopefully be swapping in a dry turbo in the very near future, so I'll need an NA expansion tank soon anyway... it'd be cool if I could get a few more weeks out of this bottle.