Coolant Issue

I was sitting in the line at the car wash yesterday (I think I'm going to stop washing the car because this is the second time in a month something has happened while sitting in that line...I guess our cars really do just want to be driven and not washed!! ) and I noticed that I was putting out a lot of exhaust. It was white and seemed to dissipate quickly so I wasn't sure if it was really anything or just steam (it was in the low 40s outside). I decided to drive the car straight home and when I was about 2 miles away, the temperature gauge shot up and the light came on saying engine too hot. I got ready to pull over and the temperature went back down as quickly as it went up, but then the coolant light started blinking and a message said low coolant. I got home and let the engine cool off. When I checked the level in the tank, it was really low. I added a gallon of coolant with a gallon of distilled water and that brought everything back up to right around the max line. I started it up a couple of times in the process and let it run for a few minutes. No indicator lights came on and temperature remained as it should. Then I would let it cool and add more coolant mix. No leaks showing anywhere but occasionally, I still saw white exhaust that smelled of coolant. Today I took the car out to run an errand. Coolant level was near max when I left and I let the car warm up as I always do until the rpms settled down. About 3 minutes into the trip, the coolant light started flashing again and the low coolant message came up. Engine temp wasn't even up to normal by then. I drove back home and looked at the coolant level and it was way low again. I eased off the reservoir cap allowing the pressure to escape and glug, glug, glug, the expansion tank begins to fill back up from the lines. But it never got back to even the MIN mark on the fill tank. Seems like it is down about a quart or so if I had to guess. Any thoughts or suggestions? I have no leaks showing under the car and everything seems to run fine. I didn't notice any excessive exhaust today either. BTW...AOS was done back in March so I doubt I have an issue there.

What year, how many miles? Did you check around the front rads and plumbing down the center of the car? What part # is on the cap, end in 04? Under the water pump completely dry? Thermostat sticking?

Its going somewhere, I would check the oil before driving any further.

fpb111...2004 C4S 48K...checked around front rads, completely under car to back, blue cap on reservoir says 447.01 on the end, water pump looks dry...no crusting around reservoir cap, thermostat could be sticking I guess, but it moves fine from cold to normal operating temp just left of the zero in "180"...

Bad.Tag...first thing I checked...with the dipstick...oil is clean and clear...I read that it would look like a milkshake if I had intermix...

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Ok good. Didnt see that mentioned initially and wanted to verify. I did have a case on mine where a leaking radiator was losing coolant but not dripping. Instead it was crusting up on the fins and I would get a strong coolant smell when spraying them in a self service bay. It was not something that was immediately noticable. Have you ever had the rads cleaned or replaced?

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Reads like the coolant got exceptionally low -- probably due to the cap leaking -- and low enough that adding the gallon of coolant probably trapped a bit of air in the system. The subsequent behavior was from this air bubble working its way out of the coolant system. You have done all the right things, checking for intermix (and check the oil level too to be sure it is not suddenly "too high") and for leaks. With no leaks then the cap becomes suspect #1 and I would replace it pronto. Be sure the coolant level is correct and keep a close eye on it. If it goes down again there's a leak. If there is my WAG (I like to get mine in early to beat the rush) is the coolant tank has a crack/split in it that only really opens up when the coolant is hot. So one pressure test you can do is to drive the car around until it is good and warm, fully up to temperature and has been for some time. Be sure the A/C is off. At home raise engine RPMs to say 1500 and hold until you hear the radiator fans come on. Then shut off the engine. The coolant is hot, based on my info 212F. With the engine off the coolant will get hotter as the heat load of the engine permeates the engine and its coolant. This raises the pressure. Hot coolant under pressure can often make a leak known that remains hidden under less demanding conditions.

+1 with getting a new cap first ~$20. Original caps, part # ending in 01, were weak and have a bad rep for partial/full failures. I think the latest part # ends in -04. 2nd look at the "frame rail" under the tank for stains that would indicate expansion tank crack. If your tank is original there is a pretty good chance that it has a crack that opens when the engine gets hot and makes pressure. Use Macster's method to check the tank. Also not the problem now, but could cause it in the future. Clean the rads so they don't corrode! Porsche 996 986 bumper removal - YouTube

Thanks for all the input...I was planning on cleaning the rads over the winter...will be first time since I've owned the car (2 years)...I'll order a new cap immediately and see if that helps It's raining here today so it's a little hard to check for leaks anywhere since the whole bottom of the car is wet. I'll let it sit til the roads are dry and then try Macster's tests to see if I can pinpoint any leaks anywhere. Has me pretty scared to drive it around right now as I don't want to overheat and do some real damage. Read up today on water pump replacement and although it doesn't seem to be an issue, I may go ahead and replace it as preventive maintenance.

get a UVeiw 550000 to make filling very easy Uview Airlift Kit 550000 Demonstration, Pressure Test, Coolant Fill - YouTube

That is pretty neat gizmo. Amazon has it for about $120.

You have a head gasket leak....

+996 to having a PRESSURE test done soonest...help you pinpoint/locate the source of the leak.

wwest...that's what I'm afraid of...but since I don't have visible intermix right now, it would have to be fairly small...and then that leads me to the next question...is there a way to test for this? Wouldn't a pressure test on a car with a cracked head gasket force coolant into the heads thereby causing more harm?

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I reread your initial post and I do have to say a head gasket leak is a possibility. I would therefore advise you to not run the engine. With a head gasket leak there could be oil in the coolant or coolant in the oil. Usual sign of oil in the coolant is globules of oil floating on top of the coolant in the tank. For oil you can drain the oil and look for coolant in the oil. If you don't want to drain the entire amount of oil just remove the oil filter housing and dump the oil out into a *clean* pan. You can pour some into a sample bottle and send it out for analysis. Among other things the analysis looks for anti-freeze compounds in the oil. Another way is to remove the plugs and check them. If there is coolant leaking into the cylinder this will clean the plug tip and electrodes and the plug from the cylinder with the leaking gasket will stand out from the other plugs. Or just take the car to a proper shop and have the system pressure tested. Oh, it might seem odd but I'd do this with the system drained of coolant. The issue with coolant leaks is if the leak is under water so to speak and the system cold even pressure may not be enough to cause enough fluid to leak out to lower the pressure that much. Really, a pressure test with the system full of coolant just tests those areas of the cooling system that are above water. By draining the coolant all areas of the cooling system are above water, are exposed to air directly, and experience air pressure directly. Even the smallest leak will let air out and you will see this as a pressure drop. But of course the above is my thinking. I'm sure your trusted tech will advise you of what he believes is appropriate.

Macster, I've checked the coolant in my reservoir and at least checked my dipstick. No signs of oil in the coolant an no signs of coolant in the oil. I'm going to drop my oil filter tonight or tomorrow to get a better look at the oil. The issue with checking the plugs will be that I just replaced all plugs and coils. This was actually the first drive after doing so, so I doulbt I have any dirty plugs to be able to see which one is clean.

Two gallons is SPECTACULARLY low. The low coolant warning is triggered when the tank is low - but that should only be a pint or so. How's the water pump bearing (can you wiggle the shaft when the belt's off)? This is a potential point of departure for coolant when the car is running and hot, but you may not see much under the car when it's parked.

5CHN3LL...I haven't checked the water pump yet...I'm going to jack it up tonight and see if I can see anything further...

Part of using the UView is to pull ~25" of vacuum and see if the system holds it for a couple of minutes. That checks the integrity of the cooling system. if it loses vacuum there is a leak somewhere. Once, when I was doing leak down on a Honda Accord, I pressurized a cylinder to 100 psi and the radiator overflow peed on my foot, found the reason it was down on power, blown head gasket.

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Unless the newer models are different both times when the low coolant warning light came on in my Boxster the level was a gallon or so low.

Wow. Thanks, Macster. I don't recall it taking anywhere near that much for either my 986 or 996. Regardless, 2 gallons is a lot of coolant to have go missing.

A head gasket leak may/might only let coolant into the cylinder when it's under vacuum, no coolant anywhere but in the exhaust.

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Agree. 2 gallons is a lot. I was surprised it took a gallon to top up the fluid level. It had never needed topping up before. Also, it didn't take long -- IIRC less than a month -- for it to go low again.

I ordered the Uview...supposed to arrive Friday. I was able to jack the car up and check a few things today...I didn't feel any play in the water pump and didn't see any visible leaks or spots on the garage floor so I'm thinking this really is a leak that only shows up under pressure. Didn't remove the bumper yet to check the radiators, but visual inspection produced no indication of leak either. I did notice one thing however, there was a drop of coolant stuck in between the motor mounted muffler bracket and the muffler mounted part of that bracket. This is leading more toward a cracked reservoir as I think that is about where it would be dripping....once I get the UView I will hopefully know more and be able to report back.. Oh and the hopefully really good news is there is still no sign of any oil in my coolant and no sign of coolant in my oil so fingers are crossed...

Was this on the driver side, towards the rear part of the engine?

Imo000...yes it was exactly drivers side toward the rear part of the engine...

nymart, if its a leak, you should be able to smell coolant when the engine is hot. If its the coolant tank, oh boy its fun to change on an 02+. If I were you I would condsider dropping the engine. I pulled my old tank before engine drop just to see how hard it was. It sucked. I put in the new tank while my engine was dropped and it was very easy!

KK you're killing me...I would love to drop my engine for a number of reasons, but I have to be honest...I'm not comfortable enough yet doing that. I took a look at it while I was checking things out this evening and I could see that it's going to be a "fun" job...but for me it's baby steps until I really get to know my way around this car before I do a full drop

Of course its easier when the engine is out but Jeebus...all that work just to make it easier. Started drinking early tonight? Sounds like the leak is coming from the tank. If the leak is from the drain tube then the leak is around the filler cap.

I got the UView today. Hooked it up and followed all of the directions, but I couldn't get it up to 25 psi. It would peak there and then sputter a bit and start spitting coolant out the tube, and back down to 20 psi. It seemed to hold the 20 psi though so I'm still searching for a leak... Anyway I filled everything up with the Uview and let the car run for a little while in the driveway. No issues, so I decided to take it for a quick ride. Again, no issues and the coolant level looked OK when I got home. Operating temperature was normal but the trip was only about 5 miles. I did pull some of the coolant out of the reservoir and took the attached picture. Seems everyone else's coolant pictures that I have seen are crystal clear. Mine is anything but as there is capital "A" written in black sharpie behind the glass and you can't see it through the coolant. Now I know the color is due to older green/yellow Porsche coolant mixed with the new pink, but the cloudiness has me concerned. Could this be a sign that it's just time for flush or something more ominous? Tomorrow I'm dropping the oil filter to check the oil more fully. Will likely send off what I pour out of the filter to Blackstone for analysis.

Forgot to mention one thing...when I got home from the drive, pulled in the garage and got out of the car, I could definitely smell coolant...seemed like it was coming from around the drivers rear wheel well...

Don't bother sending the oil. If 2 galloms went into it, you would see it.

Imo000...my concern is did 2 gallons go into it over the course of months...just seeping in and burning off. Not enough to trigger alarms (until it finally got low enough), but enough to show that I do have a cylinder crack or a head gasket leak. I have to be honest, I don't check my coolant level very often (until now)...

Never mind a month, if 2 gallons went into the oil in a year, the oil would still look like milk shake. If in a month, the oil level would also be sky high and milk shake looking. If you let the engine sit long enough for the oil and coolant to seperate, when you pull the drain plyg the firat thing you would see is clean coolant and then some mix of oil/coolant and last would be clean engine oil. If there is no sign of external leak and your oil looks normal, the only other way the coolant can dissapear is through the combustion chamber.

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Bad.Tag - I really like your avatar pic... can you post it up in full size?

Probably the coolant tank has a very small crack in it. Are you sure when you pressurize the tank the coolant is coming out of the overflow tube and not a crack in the tank. If it were a head gasket you would probably see bubbles in the coolant tank when the engine is running because it can pressurize it.

The head gaskets on these and many engines now days a multi layer steel units that pretty much never fail. If they "blow" it more likely a warped head or block than a blown gasket. You would have to severy overheat and engine for this to happen and in that case, you will have other bigger problems than a heqd gasket.

wxseed...Yes I'm sure that the UView is pulling coolant out when hooked up...no leaks seem to be originating from the tank Imo000...I hear what you're saying and from everything I've read head gaskets "blowing" are extremely rare on these cars...but I still for the life of me can't figure out where else I could be getting coolant into the combustion..

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Thanks! We have a snow thread going here with larger shots - https://rennlist.com/forums/showthre...4&referrerid=0

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Start pulling the spark plugs. The one that looks brand new is where the coolant is going. Lets hope they all look normal.

D�j� Vu! See below I thought someone had swiped my pic! I read your thread here with interest as I had a similar experience recently. New to me 99 C2 Tip with 85K miles went into a local indy for 90K service and I had the IMS, RMS, water pump and AOS replacement even though there was no obvious issues with the motor. Driving it home I got the flashing coolant light and had to add about a pint of water when I got home. Next drive I ran it pretty good on some of the local twisties and I noticed the temp spike for a split second and then the coolant warning light started flashing. This time it took about a qt. Read up on this and saw I had the original coolant cap ending in 1. Replaced that and haven't had any issues since. However I did freak out after I replaced the cap because that was the first time I noticed the color of my coolant. My first thought was oil in it but everyone including my indy seemed to think it was normal for a mixture of old and new. I haven't noticed any smoke out of the exhaust, smell of coolant and oil appears clean at the filler and dipstick so I am writing this off to a faulty cap which may have been exposed by the way I've been driving the car - hard but at slower speeds overall. I'm going to keep an eye on everything though and watch for any telltale signs of a system leak, blown head etc in the oil/coolant. As well as checking my coolant tank per Macsters post. Rich

Imo000...I'm going to do that, but my concern is that they are all going to look new...the car has only been driven 20 miles since I replaced the plugs and coils...also, I ran it in the garage yesterday with the reservoir cap off...I saw no bubbles but again who knows because I did smell coolant and there was a lot of water blowing out the exhaust...do you think I'm better off just having it towed to the shop for compression and cylinder leak tests?

RDykmans..I followed your post as well...the one thing I was concerned about with my coolant was not so much the color but the clarity...your's seems to be perfectly clear whereas mine is anything but transparent...I just don't know if maybe that's due to age or something else...

Here is a video of my exhaust from startup...initially you will see quite a bit of "smoke" then it tapers off...picks back up again around the 1:11 mark in the video and continues through the end...at the end of the video you will see the amount of water that is being spit from my exhaust pipes... I'm 99% sure that when it's smoking/steaming that it's coolant that's burning but again, I'm not a mechanic. http://www.youtube.com/watch?v=Wg2lb...ature=youtu.be

Does the steam tastes sweet? Coolant has a very sweet taste

It definitely smells sweet like coolant...I haven't actually tasted it

Nymart, from the video, the smoke and fluid dripped on the floor look like normal water condensation to me (assuming that was a cold start). The fluid is clear and thin as water. Since there's fluid spit out on both exhausts, it's unlikely you have head gasket problem on both banks at the same time. I suspect you have a coolant tank crack that the coolant leaks onto the hot exhaust and being burned off. You won't find small coolant leak with the uview vacuum tool because sometimes the crack only opens up under pressure. You can either drive your car for 20min in stop and go traffic or at higher revs to accelerate and decelerate more, then park the car and look for coolant leak. Or you can get a Stant pressure tester to pressurize the tank to 18psi and look for leak.

Ahsai...yes that was a cold start...and I would also assume just water but it seems like an awful lot and I can definitely smell coolant...I would agree that a head gasket leak on one bank would is pretty rare and on both banks, the odds are probably astronomically low...at this point I'm just scared to drive it (fear of collateral damage) and looking for anything I can do to give me more peace of mind...

I would just get the latest cap and monitor the coolant level (and oil condition) after every drive from now on. If you cannot wait, just get the Stant tester with the correct adaptor (~$90) to do a pressure test when the engine is cold. That way any leaked coolant will drip on th floor and not burnt off. This is the first thing a shop will do anyway to diagnose your problem.

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Agreed..this looks like completely normal exhaust vapor, just part of the combusion process. I'm betting its a leaking tank

Pull the plugs, that will tell you if coolant is going into the combustion chamber. Cost $0, only your time.

I am .996% sure you have a leak/crack in your coolant reservoir (had symptoms SIMILAR to yours). I decided to have WP, tank, cap, serpentine belt, t-stat and lines/hoses done at the same time...not a DIY guy so paid my indy to do it

I may have missed this if suggested earlier but you could also pressurize the coolant res and look/listen for leaks. Pretty easy to do. We mention it here within our tank replacement DIY. Keep us posted either way. Mark/Pelican Parts

So I pressurized the system to 20 psi and poked around for over an hour and found NO LEAKS ANYWHERE!!! So at this point, everything is back together and I'm chalking it up (for the time being) to a leaky cap (which has been replaced) and a lack of checking coolant level on my part. Waiting for this crappy weather to break and I'll get the car back on the road and watch the levels to see if they are dropping. Don't think there is anything else I can do at this point since I'm not seeing any signs of intermix. Thanks again to everyone for the advice.

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That sounds like a Happy New Year, indeed!

That's good new but you can still pull the plugs and see how they look and compare to each other.

Imo000...I'll definitely do that soon...at least 5 out of 6...having just grappled with that passenger side rear while replacing my plugs and coils, I'm not sure I'm ready to go through that again just now!!