Water splitted from the overflow coolant

[alcubot]

Guys I almost signed for a 986 S in 1999 with 108k km.
Price 11k euros.
The car looks very well put, ok interior, hood ok, ok paint, the engine runs very well.
The only thing I noticed: after making a nice ride over 25 km the 986 S has "spit" from the overflow coolant some water.
I touched it and it was not oiled, I checked the oil and there is NOT white foam.
I read of users who have had problems with the expansion tank, even the cap ....
The seller claims that when he put the water has simply inserted more than expected ...
What could be in your opinion?
Thanks in advance.
Antonio

[rick3000]

The most common cause of coolant (should be a 50/50 mix of coolant & distilled water) coming out out of the overflow, located above the right rear wheel, is a bad coolant cap, or an air bubble in the system.

If the seller says he was adding water, it is probably an air bubble that is causing coolant to come out of the overflow. I would ask him if he was using distilled water, if he was using regular tap water you should drain, flush, and replace all of the coolant to avoid any minerals building up in the coolant system. This would probably cost a few hundred dollars/euros to have someone do.

If he was using distilled water, you can open the purge valve under the plastic cover (see this link) and drive the car for 2 days with the valve open to let any air in the system purge itself.

Check the rear truck, around the tank/under the carpet to make sure there is no obvious leak. Look for dried white powder, the OEM coolant has an additive that dries white so you can spot any leaks. If the tank is leaking it will need to be replaced which can be pricey. The tank alone is about $400 USD.

I would also recommend getting a Pre-Purchase Inspection from someone familiar with Porsches, repairs for these cars are not cheap.

Best of luck!

[thstone]

Please get a professional PPI.

It will be the best money you will ever spend and they can actually inspect and find the source of the coolant being expelled (along with the other 100+ things that might be concerns).

[alcubot]

Thank you very very much rick!
The first check i'll do, is to see, after remove the plastic cover if the coolant cap looses water with engine in idle.
After that if any loose comes i will open the valve to let any air in the system purge itself.
It's correct?
Thank you in advance!
Antonio

[rick3000]

You probably won't be able to see the coolant cap leaking, if it is leaking. The cap is just something that normally needs to be replaced every few years.

I agree with thstone, a PPI inspection is highly recommended for any car, but especially for Porsches because the repairs cost so much.

[Shred]

Just to add to other's great advice.

@alcubot: Check if there is condensation on the rear boot/trunk above the coolant tank area.
If so, replace the coolant cap to the latest version; 04.
Check if there is water coming out from the bleed valve and made its way down to the coolant overflow which end under the car. Leaks on the ground, right side (passenger).

Check the revision version of the tank (service history?). See the last 2 numbers usually
Coolant tank - Latest: 996-106-157-04
Coolant cap - 996-106-447-04

If it's the bleed valve of the tank and your tank is pretty new and in good shape, replace bleed valve first before doing the whole tank. It worked for me.

Good luck! Ciao

[alcubot]

Thank you so mutch Shred.
Today i'll check the car, and then i'll report the forum for the updates!
Ciao a tutti!
Buona giornata

[jcslocum]

Antonio, why was he filling the tank at all is the big question?? Pull the carpet up under the tank and see if there is any wetness. If it wet, there is a cracked tank that will have to be replaced. It's a DOG of a job so be sure to really check it!!

[alcubot]

Boys after the substitution of the old cap (rev. 00) with the new one (Coolant cap - 996-106-447-04), and after have setted the level of the water at 3\4 of the max, the problem seem to be disappeared, no more water splitted.

After i've done some tests to verify the integrity of head gaskets of the engine.
1- when the temperature was at about 80 Celsius degrees i've unscrew the water cap to see if the water, when accelerating, was going up (bad signal) or down (good). In my case it was going down.:-)
2 - after i've drived the car in the higway and inside the city continuously and the indicator of the water temperature is arrived in the middle between 80 Celsius degrees and 100 Celsius degrees, so i think about 90 Celsius degrees. External temperature was about 15 Celsius degrees. 90 It's a good operating temperature?

Have you some other test to verify the the integrity of head gaskets of the engine?
Excuse me for my bad english...
Thank you in advance
A.

[jcslocum]

Your bad English is much better than our broken/bad Italian!!

I'm glad that it looks like he just overfilled the coolant tank. Keep a close eye on it.

This is how I test for a blown headgasket to see if combustion gasses are getting in to the cooling system.



This device sucks the air from the radiator or coolant tank and the purple fluid will turn yellow if there are combustion gasses present. They can be bought here for about $40.00

Combustion Leak Tester | Cooling | UView