Coolant Leak

[Tool Pants]

Maybe you will get lucky with just the cap.

The newest version is on the left and the prior version on the right.

[Kevin369]

Update:

After my first round of refilling the coolant resevoir and replacing the cap with the newer one, I drove about 10 miles and rechecked the coolant resevoir. It appeared to need a little topping up. (Maybe the coolant had not returned to the resevoir or coolant was filled up in the radiator and/or hoses?) I topped it up and drove another 50 miles in mostly 100 degree heat over the course of a day and half. I checked the coolant level after about 35 miles and it was the same as after the top up. I checked it again after the next 15 miles and it's still topped up. The car has been running consistently at about 185 degrees.

I think I got lucky and that the problem was the old cap. I'm going to keep monitoring it and continue to carry a bottle of 50/50 mixed coolant/distilled water around just in case.

Thanks for all the advice!

[openwater]

Looks like you lucked out, I'm jealous. ;)

FYI... for anyone who keeps coolant laying around the garage, the stuff is deadly when ingested in modest amounts and animals (especially dogs) love the taste. Their low body weight means just a little does significant liver damage and usually results in death. Keep Fido safe, treat the stuff with care...

[Eric in Dallas]

Because much of the problem on these tanks is heat, the oil filler tube also fails as it is in the same (not well ventilated) area.

I really really lucked out as my dealer replaced both a month before my warranty ran out ( I had a failed filler tube and a very small tank leak).

I just wanted to raise the issue of checking the filler tube when you have the tank out and easy access to the oil tube.

[jsq]

Glad this thread seems to still be active.

I'm in more or less the same boat but with a small twist.

Last sunday I was doing a mountain run with two 993s. The hill climb is hard and the car normally runs at about 190-200. It's mostly a 2nd gear 6k climb witht he occasional quick grab of 3rd. The boxster has done it a few times before in the heat and even chasing 993s has had no problems. 2/3 of the way up the mountain the temp needle pegs and the red light comes on. I pull her over and shut the engine off but leave the key in pos. 1 to keep the fans running. Jump out and have a look around back. Coolant is POURING our of the corner by the pass rear tire. I pop the trunk. All kinds of steam coming out of the cap. However the carpet is dry. Key is still in so the gauge is still active and the sucker is red hot. Got to cool it down fast!!! Jump in the car and crank the HVAC heat to max with the fans at max. Start it up and turn it around. Put it in neutral and start coasting down the mountain to get some air flow over that sucker. Instantly the temp starts to drop. Within a couple minutes it's at normal temp. Ride it on down to the bottom of the hill and shut er off. Temp is cool enough to open the fill port. The level has dropped about 2.5" below min. Top it up with water. Start it up. Seems ok. Decide to go up the mountain at 3/4 speed and see how it does. It's fine. Get on it through the top sections. Still fine. Pull over at the top with the 993s. Leave the key in pos. 1. Fans don't seem to be on. Temp spikes! more coolant comes out (not nearly as much). Check the fuses on the radiator fans. They're ok. Fans come on after a minute or so. Temp is still high. Jump in and head down the back side of the mountain with the 993s. Temp drops instantly. It runs fine all the way down the backside. At the bottom of the hill I don't want to shut it off. Idling at the side of the road it doesn't overheat. Coolant level is holding. Drive it all the way home (40miles). No problems. Shut it off. No problems. Drive it on an errand. No problems. Coolant level is a little low. Top it up.

So the car has sat since sunday while I've been reading up on my little problem. I'm thinking the classic split tank. Pull all the carpet and board out of the trunk today. Little to no residue anywhere and the carpet is totally dry. Tank appears to be fine. What gives? Might be a faulty cap, but that wouldn't explain the coolant pouring out the bottom. Car ran and cooled fine after the loss but haven't driven it since sunday.

The only other thing that happened before the run was the day prior when I changed the oil and pressure washed and degreased the underside of the engine bay. I mean I layed into it with a pressure washer (with the engine running of course). I suppose I could have screwed something up with the pressure washer but I imagine if I did I would have had problems long before the 50 hard miles or so I drove on Sunday before the overheat.

Any thoughts?

How did i lose so much coolant so dramatically with out getting it in the trunk? Where am I losing if from? What detective work can I do?

Any help would be much appreciated.

thanks.

UPDATE: When I pulled the plastic cover off of the fill port cluster, there was lots of coolant residue in there. Of course I wasn't suprised the way the sucker was steaming over on sunday, but then I looked at what appears to be a drain tube in the middle of the cluster. Is it possible that my cap is bad (I have the old style) and all that coolant boiled over thru the cap and came out the drain tube??? Would that account for it overheating in the first place?

Edited July 21, 2004 by jsq

[mrmickeymouse]

Start with the cap [replace with above mentioned], pressure check the system and then report back.

You seem pretty intuitive to your vehicles needs. I believe you will figure it out upon the pressure test.

[openwater]

Steam is not normal in a fully closed system, I think you'll find the cap is your problem... The overflow in the center of the 'cluster' empties out at the right rear wheel, just as you experienced on the road. As a test, pour a quart or so of water directly into the overflow and watch where it comes out... The fact that your temp returned to nearly normal is not surprising, when my tank failed I could keep it below 200 by going as slow as 20 MPH on flat ground. As for the power washing, I doubt you would have enough direct access to the more vulnerable rubber tubing behind the firewall to do any damage... Hope this helps.

[Kevin369]

I agree with the other responses. I got lucky with just the cap but it is amazing what a bad cap will cause. Sounds like the bad cap allowed coolant to escape under pressure and drain out. A small thing I found odd about your experience is that you said that your Boxster normally runs 190-200. That seems high to me because mine never goes over about 185 and that's even in my 100-115 summers days.

Just a quick update on my coolant issue I posted about:

I haven't driven the car that much since. (100-115 days is not conducive to Boxster driving since I believe that it should be driven top down.) None the less, the coolant level has been holding steady each time I check it. I let the car sit and let the coolant return to the resevoir before checking. All seems well. Phew! Even still, I can tell you a bottle of Porsche coolant fits snugly between the spare tire and the firewall. :)

[d9b]

Ok time for me to jump in on this thread. I've had my '00 Boxster just over 3 months, and I've seen coolant dripping at the right rear tire location not long after I got the car.

After reading this thread - I looked under the cover of the 'cluster' and noticed residue. I had the old cap, so I went out and spent $35 on a new cap and a quart of coolant. I cleaned out the old residue and tightened the new cap down leaving the cover off so I could see if the new cap was leaking.

I'm still having the problem with a pool underneath the car after driving in the middle of the day (engine temp has always been fine). No residue around the cap. The leaking fluid is not significant (maybe 4 oz. each incident).

I haven't pulled the carpet out yet, but I will do this soon. I've done a lot stereo work on other cars, so I was wondering if there are some tricks to pulling the carpet without damaging the plastic tabs that hold it down. I searched the forums for a topic on the carpet removal, but didn't find anything. I know this is probably no big deal, but I don't want the carpet to be loose when I reinstall it.

Next step after that will be the pressure test - I can do that at any shop that works on radiators? Thanks for the help...

[openwater]

I found the carpet removal to be pretty easy. I worked the plastic tabs with my finger to find the 'sweat spot' that makes removal easier. A quarter turn either way will do the trick. After removing all the tabs I started at the right end of the trunk but in retrospect starting at the left will make it easier to work the carpet from under the edge of the reservoir. Don't forget to remove the trunk light cover... I almost pulled my wires on accident. In my '99 there is a 3-piece styrofoam insert that sits under the carpet. Two-sided tape holds them together and I found it necessary to pull the carpet from the styrofoam to remove it. Other may have a different experience. The styrofoam is molded and sits in place without connectors. When I reinstalled the carpet I just worked in reverse order, reapplying new tape to hold the carpet down. Pretty easy.

As for the leak... Your diagnosis seems right on. Have you noticed a coolant loss through the check window? I would think 4oz each time would drop your level by about an eighth of an inch or so... Also, on hot days you may get a whiff of hot coolant smell right when you open the trunk and after driving. Thats the coolant on the trunk floor...

[Kevin369]

There's no real trick to remove the carpet. The carpet around the coolant resevoir has foil backing so be careful with that. It is a seperate piece. There is another seperate piece that is behind the tail light assembly. The main carpet covers a foam board and that carpet is taped to it. The only kind of tricky part is removing the plastic rivets and screws. I hate breaking plastic fasteners but using a handy Snap-On tool for this purpose prevented that. Everything else pretty much pops right back into place as it is more or less molded to shape.

[d9b]

I pulled the carpet out tonight - like you guys said not a big deal. I was surprised to find .... nothing. No pooling at all and clean as a whistle. This car was rear-ended with the previous owner (my in-laws :P ) so the coolant resevoir was likely replaced. (The car had 13K miles on it when I acquired it).

I felt around the bottom of the resevoir and couldn't feel anything that might be leaking coolant. I also noticed that on the trunk lid, in the oval that is directly above the 'cluster', there was condensation that I'm pretty certain is coolant. I've never done this before, but I'll try and post some pics in the next reply...

So my leading theory at this point is my new cap is faulty. I'm hoping this is the case because it is the cheapest alternative at this point. As a first attempt, I will go back to the dealer and trade out the cap. After that I will try the pressure test.

[d9b]

Hope this works...

Remove Carpet

Tank

Cluster

Condensation

[Kevin369]

Yes, that looks good. Did you say that you already have the newer cap? (The pics show you do.) I guess trying to another one wouldn't hurt. Be careful when putting it on as it is easy to cross-thread them and thus not have a tight seal. (My service advisor warned me of this.) It's easy to do but if you just lightly spin it and let it thread on its own.

Keep us posted.

[wonghoiman]

on my 2000 boxster S, my coolant level is a few inches below the MIN mark. Adding 2-3 quarts of water doesn't seemed to help as it was back down to the level after some driving. I couldn't discover any coolant leaks in the trunk and elsewhere. I have the new cap already. But I did discover my oil lever is now one bar over the top(it's normally at mid-level).

did anyone encounter this problem? Adding water to coolant reservior tank but the water seemed to somehow mixing up with engine oil?

thx,

victor

[adsach]

on my 2000 boxster S, my coolant level is a few inches below the MIN mark. Adding 2-3 quarts of water doesn't seemed to help as it was back down to the level after some driving. I couldn't discover any coolant leaks in the trunk and elsewhere. I have the new cap already. But I did discover my oil lever is now one bar over the top(it's normally at mid-level).

did anyone encounter this problem? Adding water to coolant reservior tank but the water seemed to somehow mixing up with engine oil?

thx,

victor

Check the color of your oil. If there is water mixed in the oil, it will appear gray-brown and maybe frothy or sludgy.

Water mixing up with engine oil is very bad. :cursing:

Normally the synthetic oil in your car should look like it is perfectly fresh out of the bottle.

[wonghoiman]

I just jack up the car and let the oil drain. I could see that clearly some water came up first....the oil is very muddy...exactly like hot chocolate over fresh oil....will let it drain then add some water to coolant reservoir and see if the water will come out....

any expert advice on what to do?? And how much it'd cost at the dealership to fix this problem?

Edited December 2, 2005 by wonghoiman

[Tool Pants]

If you have coolant in the oil then the usual cause is a blown head gasket or a cracked cylinder liner. Head gasket can be replace. Cracked liner means a replacement engine.

[theredcouch]

Please help. I walked out to my car after a short drive and discovered steam coming out of the right side engine vent on my '97 Boxster and coolant coming out from underneath. I drove the car home carefully and the temperature stayed around 180, the engine light was on.

After reading these previous posts I checked my coolant cap (fine) and under the carpet of my trunk (fine). I looked in the engine bay but couldn't see anything obvious (there are so many engine parts in the way).

Is there anything that the mechanically un-inclined, like me, could to do try to trouble-shoot the leak without a bunch of fancy tools before taking it to the shop?

Also, if/when I do take it in will it be ok to drive the 15 highway miles if I fill the coolant back up first?

Thank you all in advance for your replies,

Tim

p.s. There does not apear to be any oil mixed in with the coolant.

Edited February 22, 2006 by theredcouch

[openwater]

I assume by 'engine light' you mean the red lamp to the right of the temperature guage... This illuminates when your coolant tank level sensor reads near zero, regardless of the operating temperature. I would remove your engine cover, stand next to the passenger side vent, look under the right rear edge of the opening toward the firewall. You'll see four tubes coming through from the trunk; the large oil filler tube, two that carry coolant, and one that serves as an overflow. Fill the tank. Look for leaks in the two with coolant. It's cramped, you'll need a small flash light. I would initially do this with the engine cold to get oriented, then when hot to find the leak. If you attempt this while the engine is running, BEWARE. I would fear for my eyes, upholstery, paint and top!

[Axle]

Openwater and Tool Pants,

Thanks for all the info and pictures. I was amazed to find the exact description of my problem in Openwater's first post. The milage on my 1999 Boxster was 154482, about the same as everyone else.

I first removed the carpet and found the lake. I bought a new Equalizing Tank (996-106-147-08), Anti Freeze as well as the cap ending in 1 from the dealer. Total cost was ~ $382 ($50 for the Anti Freeze). I was going to do the replacment myself, but work got in the way. I ended up taking everything to a local mechanic (San Jose, CA) who had me up and running in one day. Glad I had him do it, he said it was a pain. He only charged me $100 for the labor. When I got the old tank it looked exactly like the pictures you posted. Once again, thanks for the help.

Axle

[Respirologyrc]

So it's been a while since anyone has posted on this problem, and i thought i would share my experience of this issue being that i just had it happen to me.

I have a 1999 Boxster 2.5L Polar white paint with 61k

I drove the car 50 miles, no problems. Stopped went into a store, and when i came out all of my coolant was on the ground. I check my coolant tank and saw it below min level. There was a lot of coolant fluid around my coolant cap (green in color). It turns out that i have the older faulty coolant cap. Either way 2 days later i pull up the carpet and find zero green haze or any puddles. Being that my car is white i would assume that even dried up antifreeze inside my trunk compartment would be evident. Because i didn't see any residue i did still run my finger across the trunk around the area of the coolant tank. It felt sticky and my finger appeared to have some sort of silver residue or lubricant on it. Was this dried up antifreeze?

I filled the coolant tank back within normal range, and proceeded to drive home. Just like everyone else---zero issues and temp staying at 185.

Is it possilble that enough antifreeze came up through the coolant cap and spilled out down the drain tube? Mind you i drove my car 50miles in 100 degree weather with the AC high. Also i didn't see if the anitfreeze came pouring out or if it just spilled out then pooled to form a puddle around my right rear tire.

Thank you guys

[tibi]

Here is a ghetto fix - try this before removing coolant tank

I tried J-B Weld ($6.75 Home Depot) takes 15 hours to cure sucks to work with handles temp range (did not work) then I tried the J-B Weld Putty ($6.50 Home Depot) - cures in 1 hour - did not work period.

Then I did some research and found VersaChem Plastic Welder Part No. 47809, cream color ($7.00 O'Reilly's Auto Parts) - this product handles temps up to 300 degree and 3500 PSI - easy to work with after a 2 minute wait time, cures in 15 minutes, hardens fully in 24 hour, WORKS great saved $295 on new coolant tank. You would need to unscrew all 4 bolts on the tank to get it to move around so you can get your fingers into the leaking spot (used paper napkin to trace leak) and empty coolant out of tank. Hope this helps someone...

Regards

Ted