Coolant level issue

[siddharth]

Hi guys,

I had to add almost 1Liter of water the other day to get rid of the check coolant level flashing light on the dash. This is after the dealer put some 3 weeks back to top off (it was flashing back then too).

Anyway after yesterday's addition of 1 liter of water, I thought the coolant tank might be cracked as most others reported. So I ventured out to inspect mine. Well, after a lot of backbreaking effort I managed to get the coolant tank out. And I think in the process I broke the coolant level sensor. Either that or it was broken from before (the plastic base is broken)

Now, the thing I found was that I couldn't really identify any crack on the coolant tank !!!

Q1) Is there a problematic area I should look closer at ?

Q2) Also, given this tank is prone to cracking (from what I read), how are the cracks ? Hairline or wide ? The car body around the coolant tank didn't look corroded/spoilt - just dusty and dirty.

The current parts I have are

Coolant Sensor : 99664150300 (I need a new one).

Coolant Cap : 99610644700

Coolant Tank : 99610614756

Q3) Should I really replace any part with a newer part now that I've opened things up ?

Q4) If you think the coolant tank/cap is ok, what else should I look at ?

Q5) Is it normal to lose coolant like this ? Am I looking for a problem that doesn't exist ??

Thanks guys !!

:cheers:

Sid

[Tool Pants]

Here are the cracks in my Boxster tank.

You have the old cap, so replace it.

If it were me I would replace the suspect tank since it is already out.

[rcg412]

Here are the cracks in my Boxster tank.

You have the old cap, so replace it.

If it were me I would replace the suspect tank since it is already out.

TP - what is exactly wrong with the .00 cap? I upgraded to the .01, but am still trying to figure out the differences, they look almost identical... Ross

[Loren]

The 00 caps will not hold pressure - then leak. If you put a 00 cap on a cap tester it will fail to hold pressure - the design of the 01 cap sealing and pressure relief is different than the 00.

[ScottArizona]

Funny, I've got my coolant tank out right now too. I would not have noticed a crack at all (showed up as a very small dark line, mabye one or two centimeters long), if it had not been for the small amount of crusty coolant that surrounded it. I too had trouble getting mine out, and ended up actually removing the air pump thing instead of just tying it back as in the DIY on this site, that seemed to help. While mine is out I am also changing the sensor for good measure (only about 10 bucks at sunset) and the cap (I too have the '00 cap).

My question is this: mine was a quart low when I had the ppi done, but the coolant light never once flashed? makes me wonder if someone disabled the bulb to mask a problem? I really hope that is not the case, because I've seen 996's that had chronic coolant light flashing that turned out to be a head gasket.

[eastriver]

Here are the cracks in my Boxster tank.

You have the old cap, so replace it.

If it were me I would replace the suspect tank since it is already out.

TP - what is exactly wrong with the .00 cap? I upgraded to the .01, but am still trying to figure out the differences, they look almost identical... Ross

i will take a pic. of the 00 cap and 01 cap when i got home tonight, very interesting designe change.

[rcg412]

Here are the cracks in my Boxster tank.

You have the old cap, so replace it.

If it were me I would replace the suspect tank since it is already out.

TP - what is exactly wrong with the .00 cap? I upgraded to the .01, but am still trying to figure out the differences, they look almost identical... Ross

i will take a pic. of the 00 cap and 01 cap when i got home tonight, very interesting designe change.

really??? my 00 and 01 look very similair, they both have the mesh on the inside.

[Loren]

Contributing Member geoff posted this pic some time back (and I think tool Pants posted pics too).

Old on left - new on right.

[ScottArizona]

Kinda ironic how the "new" style seems to have much more "coolant crud" (indicating more coolant pass by) than the older version.

[Loren]

That maybe from refilling... or he may have reversed the pic. They are different and the bottom line here is you do not want a coolant cap that ends in 00. Even new 00 caps have been know to not hold pressure.

[rcg412]

I stand corrected. :D

[911dark]

Use shop air and presure test the tank, give it a few min and you should be able to see the leak. At the very least it won't hold presure. It worked great for me testing some plastic fuel tanks for an experimental plane. I let it set overnight with no loss of presure. Obviously you need to stay below the cap relief presure. I would assume it is 15psi or so correct?

Edited March 17, 2006 by 911dark

[siddharth]

Here are the cracks in my Boxster tank.

You have the old cap, so replace it.

If it were me I would replace the suspect tank since it is already out.

Thanks toolpants !! The picture helped me a lot to find the crack on my coolant tank. Here it is:

I took it to the dealership and they too confirmed it to be cracked and recommended that I put in a the newer tank, newer cap, a new sensor and new coolant.

My coolant tank should arrive from sunset late next week, so till then the car is lonely in the garage ! BTW, sunset will save me almost $100 against my local dealership (which is one of the inexpensive ones in southern california!).

One final question before wrapping up ... should I put in newer coolant or reuse the existing drained coolant ? I've attached a photo of my drained coolant.

One technician told me to reuse another told me to put in new. He did mention that the new will mix with the existing trapped in the system (since I didn't do a pressure flush) but said its still better than just reusing the existing one.

What do you guys think ??

BTW, the coolant in the photo appears very dark but the coolant is green when in a shallow cup and there isin't any oil or even suspended stuff. I guess when seeing over 1 foot in depth of coolant it appears dark. But this is normal I suppose ??

cheers!

Sid

[Loren]

I personally would reuse it after filtering it (if it is as green and clean as you say). You will still need to top up the tank and then add even more after bleeding the system for a few days.

[ScottArizona]

I just reinstalled mine tonight (after recieving new tank, cap, and sensor from sunset, also at an awesome savings!).

Mine took a little wiggling to get back in, but since I already had the air pump out it was not too bad. About an hour of work, start to finish. I'm off to drive with the bleed valve open. Hopefully you'll be up and running soon. Good luck. Scott.

[eastriver]

Contributing Member geoff posted this pic some time back (and I think tool Pants posted pics too).

Old on left - new on right.

from my limited engineering class back in college many years ago.

the new design has the "neck" so when coolant spoils out, it will drop back to the coolant reserver along the edge of the neck, instead of keep on the pad, finding it's way out from the coolant reservior.

my old cap did hold pressure tight, but coolant kept seeping out, leaving a bad smell after driving for a hour or 2. after i change to the new design, no more bad coolant smell!

so again, change 00 cap no matter what! cheap part too.

loren, does this make me a "Contributing Member " even though i didn't have to post a pic. cause someone did before? :clapping:

[Tool Pants]

Thanks toolpants !! The picture helped me a lot to find the crack on my coolant tank. Here it is:

Sid

That's it. The Geiger Syndrome.

http://www.renntech.org/forums/index.php?s...=7921&hl=Geiger