What does burnt coolant smell like? What type of smell should I be on the look out for? Something sweet?

 

Random thoughts keeping me awake :

1. Prior to this shop replacing the pump and cap, there was no problem with coolant loss. Can this shop have botched up the water pump job and thus causing loss of coolant?

2. I didn't have time today to drive the 996tt tonight to sniff out the radiators. If there was a radiator leak after a drive that cause a coolant drop from max to below min, would there be white residue around the radiators? Guess the front bumper would need to come off to confirm?

Checking underneath the car today I don't see any drips or puddles on the floor.

Ugh.

 

In a pinch you can top off with distilled water. While this might dilute the anti-freeze a bit unless you live where it is arctic cold the freeze protection should be sufficient. If you are really worried you test the coolant for how low a temperature its freeze protection is good for.

 

The shop could have botched the job. If the shop didn't get a hose back on right or if the pump/T-stat is leaking.

The radiators can leak. They may not leak when cold and pressure is low but they can leak when hot. Might not leak a lot so you may not see any coolant on the ground.

You can shine a bright flash light into the radiator duct openings and look for leak sign. Most often the leak is along where the bottom (or top) tank and the radiator fins meet. But of course a leak could be anywhere.

Nice too to get the car in the air because then you can check from under neath for leak sign. You can really get up close to the water pump, the T-Stat, hoses, hose connections and hose fittings in the block.

You can look up at the coolant tank for any signs of leakage from it or its hose connections. You can check up front for any leak sign from the bottom or the back of the radiators.

IF you are lucky there can be a bit of residue. In one case I had a Mustang radiator leaking and fortunately it was leaking from a pinhole in the radiator proper and it just happened to be visible. The only telltale was a bit of stain on the otherwise darker radiator metal. If the leak had been between the cooling tubes or on the front of the radiator would have never spotted the leak sign. (But I knew there was a leak as there was a puddle of coolant under the car when I walked out to it in the hotel parking lot.)

You can use your nose if you get the system hot and then shut off the engine and let the engine heat heat soak the coolant and raise its temperature and pressure. Because things are hot a leak is more likely to manifest itself.

When I "hot pressure" tested my Boxster's cooling system and the coolant tank gushed hot coolant I let the car sit overnight.

Next morning I removed the cap and dumped in around a gallon of distilled water. There was nothing running out of the tank. I put the cap on and drove the car a couple of miles to the dealer and still even after I got to the dealer and parked the car there was no leak. Heat (and pressure) makes a big difference.

I do not think the engine has an intermix problem. Far more engines, even Mezger's suffer from a leaking radiator, hose, hose fitting, than suffer from a cracked head or block.

 

I'd top off the coolant, make sure you have a good cap that isn't cross threaded on, drive it for an hour, stopping to check once or twice then park it and sleep tight. In the morning see if it's lower.

 

IIRC, in their Porsche 997 shop manual, AllData specifies the coolant as Elf Glacelf. This was the first time I ever saw that confirmed anywhere in (semi-official) literature. This is apparently more or less equivalent to Chevron/Havoline Dex-Cool. See the posts by Tool-Pants in the threads below.

http://www.renntech.org/forums/topic/182-antifreeze/
http://babblers.org/showthread.php?t=4323



All that said, manufacturers take the question of which coolant very seriously, because these days it is specified as "lifetime coolant" - meaning that, in theory, the coolant should retain most of its anti-corrosive, etc. properties for many years. In practice, very few cooling systems will ever remain intact over the life of a vehicle, so, as long as you flush the system, do not mix coolant types, and use a quality coolant specified for aluminum, all is good. All THAT said, using Porsche coolant will cause you the least amount of worry (something that would do you good, I believe ). http://www.pelicanparts.com/catalog/..._pg1.htm#item0

Doc, you need to relax. You'll end up having to sell the car due to ulcers
And if your tech continues to tell you stories about cracked heads due to the coolant level dropping a few mm's, you need a new indy. Porsche cooling systems are large. They contain easily 3-4 times the amount of coolant that an ordinary car has. And even in a normal car coolant can leak somewhere hot and evaporate without leaving a puddle. This is sometimes noticeable only due to the smell...

It's a Porsche, but it's just a car.

 

How much coolant have you lost/added since the shop work? 1 - 2 gallons? Does the tank empty completely each time you drive it?
Maybe there was some air trapped in the system after the work was completed that got burped out dropping the level? The amount of coolant between min - max is about 1liter.
Once again when you fill the COLD engine don't fill it to max or it will vent coolant out of the cap vent to make room for expanding coolant.

 

It smells kind of like maple syrup

 

I would not be concerned of cracked heads or coolant escaping into combustion chamber. This sounds like either the shop did not get a proper seal when replacing water pump or there is a lot of air in the system..

Either way, I'd be a bit concerned that this shop has told you that it is probably not coolant you smell, but it is because you slip the clutch too much, and then suggesting maybe you have cracked heads or other severe engine problem. If you're a PCA member and part of the PNWR group, I think I know what shop you took your car to based on a photo that was posted and I'm honestly shocked with the issues you are having, they have always held a great reputation

 

I did a search online and couldn't find a single case of Mezger suffering from a cracked head of block, or water/oil mixing. Seems to be an iissue on the M96 996, but no on the Mezger blocks.

My hunch now is a botched job.

Will do. I plan on driving it to the shop, have them unscrew the cap that I can't unscrew, and top of the coolant in front of me. Then I'm going to drive it off and see what happens.

I agree here. I just don't see this being a case of cracked head. Other than this car having a reliable UMW tune, there are no mods and this car was NOT tracked or abused. My first choice indy shop was actually another shop, but this latter one was moving and they were busy with the move. In hindsight I should have waited.

I'm definitely going to question this shop about the water pump install, hoses, radiator tank leaks, and ask again about the coolant reservoir. I asked them originally to replace the reservoir but they declined, saying it was ok... saying again they pressure tested the coolant system and finding no leaks. This pressure test is what I'm confused about. If there is no loss of coolant pressure due to the test, where the heck is the coolant going?

 

My nose must not be what it used to be.

Now that you mention maple syrup, the interior cabin has a bit of sweet smell to it. I thought it was just the car's aroma.

Anyone around here care to take a sniff?

 

I saw the shop 6 days ago. Level was a bit below Min and above "996 marking" when I told the shop about coolant loss then. Shop didn't see anything, and claimed they topped it off (not sure to what level b/c I didn't physically see the tech add coolant) that day.

After leaving the shop and driving it ~10-15 mile I noticed the level was below Min, slightly above the "996 marking." Coincidence?

Have appt with shop tomorrow morning and having them unscrew the coolant cap b/c I can't twist the dam thing loose, and having them top off the coolant in front of me to MAX. Haven't driven it for 3 days now, and coolant level hasn't changed. I'd be ecstatic if it's just lots of air bubbles in the system.

After getting it topped off, would you recommend the pressure relief valve be up?

 

Just a note here on my personal experience. When i replaced the water pump in my 99 C4 it took almost 1-2 weeks and 500 miles of driving before the coolant level stopped dropping. I rack it up me not using the vacuum fill method and that was just how long it took to get all the air out of the system. On my current 02 turbo i replaced the heater core about a month ago. I did not drain the system just pulled the hoses off after relieving any pressure in the system and no coolant ran out. Put the new heater core in topped off the coolant about 5 times during 200 miles of driving before it stopped dropping. Seems stable now. Apparently there are a lot of places for air to collect in the the system and it does not like to just swoosh out. I would drive yours with the breather closed now that you have gone this long and see how it goes. Also take it out and foot to the floor, redline it several times, give those bubbles hell.

 

If you want some help this weekend, I'd be able to help you with a lift and an overview of the car. PM me.

 

Good man!!

I'd also offer to be of assistance, but seeing this I think you're better off going with the guy that has easy access to a lift rather than just my nose.

Peter, let us know what the shop says when you take it back there today. Very interested to hear the outcome.