Saturn guys, some help?

Went up to the farm today (buddy of mine's an organic farmer, I participate in their co-op), he asked me to look at his co-owner's wife's Saturn. It's a 99, don't know which model, but it's a coupe with the DOHC. It's got a coolant loss problem, but no obvious external leaks. I had him fire it up, tried to get it hot enough to turn on the fans, but it never got that hot, once we refilled it (the coolant bottle was dry when I first looked at it, did the refill first). The guy says they quit using the car because the low coolant level light kept coming on, and she started going to a shop for a refill (the guy's cool, but mechanically clueless). He could not tell me how often the thing has to be refilled, and neither can she. They also can't tell me whether or not the thing's ever been overheated..they just look at the light when it turns on, rather than noticing where the needle is on the gauge when it happens.

Car actually runs pretty good, I don't see any "milk" in the oil, don't hear any knocks or misfires at idle..and no white smoke out of the tailpipe. Where else do they leak from? Didn't see anything down at the water pump (or bad hoses, either), but I know absolutely nothing about these cars.

Also..when revving the thing while trying to get it hot enough to see if it was a closed thermostat, I noticed that at about 4200rpm, the thing acted like I'd hit some kind of rev limiter. Serious misfires. I played around with the engine for several minutes, always ran smooth as long as I kept the revs below that.

Any clue will help. Apologies for not researching a Saturn forum first..but my experience on marque forums is why the berkeley I decided to come play on the GRM forums in the first stinking place..

EDIT: I never got it hot enough to even get the radiator fan to turn on. Temp gauge stayed at about 1/4th of its range, whether it idled, or I ran the thing at 4Krpm trying to get it hot.

They have a lower rev limiter in neutral, but that's about the only thing i can really say to help you right now.

it wont get hot enough at idle unless its 85 or 90 outside. gotta load it. so go and drive.... any access to a cooling system pressure tester?

Thanks guys. Katy, I think I know where I can borrow a pressure tester. Celica, that sounds about right. I never drove it, just kinda futzed around with it.

those sc2's are pretty nice cars, is it an auto or stick?

Check the radiator. The plastic ends often crack and leak. And yeah, there's a 4k rev limiter unless you're doing more than a few MPH. I think of it as poor man's launch control.

White_and_Nerdy wrote: And yeah, there's a 4k rev limiter unless you're doing more than a few MPH. I think of it as poor man's launch control.

Don't laugh, lots of Saturn people that dragged S-series cars back in the day used that, and it works pretty darned well haha. On the Saturn forums, you'd get the ricer saying, "How do I get rid of that whack neutral rev limiter yo?" And we'd reply, "Uh, just don't rev your engine unnecessarily like a moron?"

If it's not losing coolant in any obvious places, I would check the interior behind the radio/HVAC panel (heater core), the small hose that runs from the top of the expansion tank to the back of the intake manifold, and those radiator end tanks. They love springing pinhole leaks that you'll never find unless it's up to temperature and you put a big load on the engine (merging onto a highway, for example). Also, you can check for system pressure by SLOWLY loosening the expansion tank cap and listening for a hiss when the car's up to temp. No hiss, has a bad leak.

Simple solution, I will make the problem go away. All the way to Marietta, GA!

Okay..digdug, stick. WaN, thanks. Should have known to look for the cracks, my VWs all have plastic fittings on the rad as well. TwinCam, I never even thought about the heater core, but didn't smell any coolant in the interior. I'll try the overflow tank trick (and warm it up properly first, thanks again Katy!). Car hadn't been run in awhile, tho. Maroon..that might actually be possible! They're looking to get rid of it pretty soon (don't know whether that means months or weeks, tho). You want me to investigate?

And thanks to everyone for the rev-limit in neutral thing. Sure makes my diagnosis a lot easier! I'd never seen anything like that before.

Actually, I was just telling Duke of Understeer that I was lusting after a Manual SC2 for H Stock duties. Sure, let me know when and how much. Is it a true coupe, or a 3rd door coupe?

The level sensor is pretty sensitive on those. I had the same problem for a while. It turned out to be a small leak at the water pump (only when hot). Another place to look is where the plastic meets the metal on the radiator. Small cracks develop there over time. This can be cured with some well placed jb weld. A buddy of mine autox'ed his for years on a jb weld radiator repair. Rev limit is normal in neutral/park and it cuts the fuel, hence the nasty noises. To get the fan to turn on, fire up the a/c, then shut it off. The fan comes on automatically with the a/c and will stay on for a while. Good luck!

In reply to Maroon92:

You're about to recieve a PM..

In reply to Lateralgforce:

Thx, dude. Water pump's not making any noise, but if the leak's small enough, I guess it wouldn't. Any advice on where to look for where the pump leaks from?