Paul Waterloo

I looked in the engine compartment last week and noticed that there was a little dried up coolant around expansion tank cap. It wasn't there when I bought the car, but I did remove it once before winter set in to check the anti-freeze protection level....verified it was a 50/50 mix.

Here's a picture of the OLD cap, which was a 00 suffix, probably the original cap on the car.



So I ended up buying a new cap with the 04 suffix, and yesterday I installed it. The coolant level was between low and high when I put it in, I added a few ounces of water just to make sure the level was there, the car was somewhere between stone cold and operational temperature. The coolant level was 1/2 way between low and high. I tightened the cap very tight by hand and let the car sit over night.

Today I drove the car up to a car event, let it sit there for a few hours, drove the 20 miles back home and put it in the garage. I drove spirited, but not hard by any means. I am probably just thinking I smelt smells that I normally don't smell when I was the last 4 miles from home, which are on side streets vs. highway.

After about 3 hours, I took the car over to Home Depot, a few miles away, drove it back home and when pulling in the garage I noticed a leak on the garage floor. It appeared to be coolant, sweet smelling, definitely not oil, and there was a few ounces. Here's a picture AFTER I wiped it up. The garage pitches towards the garage door. I placed the car where I thought it would be the last time I pulled it in for this picture. You can see it's really close to the exhaust, or maybe just in front of it, but appears to be in line with the left exhaust pipe.

NOTHING has dropped out of the car since my return trip from Home Depot, I put clean carboard under the car and there is nothing on it.

NOTE: I have a lot of clear coat materials on the garage floor, that's from wood working projects, the area that appears to be wet is the area...the other spots are varnishes that have cured on the floor.





And here is the expansion tank cap (new one, 04 suffix), you can see there is no coolant leaking by it. The little bit on the right was not cleaned up yesterday.



When I first figured this out, and the engine was still hot, the level was below "min", but still on the part of the reservoir that sticks out, so it could be read below the "min". Now that it's an hour or two later, it has dropped down below the shelf part of the reservoir. But you can still see the coolant in the main reservoir section. I have not cracked open the cap, it is still a sealed system.



What do you suggest that I do? I don't think it's coming out of the exhaust, but anything is possible.....I was going to let the car cool down and then start it up and see if anything comes out of there.

It does appear that there could be coolant leaking down on the left side muffler, I don't think it's salt left over from my ride home from Reno, NV last year. I cleaned the heck out of the car since then. The right muffler does not show anything leaking on it, so if it was salt, it would be on both mufflers.

Thanks for you input.....I figured I would post before I do anything else.

Paul Waterloo

BTW, the oil level is full (changed it not more than 500 miles ago) and perfectly clean. The oil fill tube is clean also.

Ahsai

Looks like the typical coolant tank leak. Your tank looks quite yellow so it may be on borrowed time already.

You can try to use an inpsection mirror to check the bottom and back of the tank and see if you could see where the leak is coming from after a spirited drive. If you can't see any leak, you will need a pressure tester (e.g., Stant) and an inspection mirror to diagnose it further.

wildbilly32

Paul: I had similar situation first drive this spring. Had put a new 04 Blue cap on replacing the old Black Blau version as a preventative. After driving up to temp and enjoying for a few mile brought back to garage and smelled anti-freeze. Yep, small puddle beneath left side muffler. Difference is I opened hood and noted water spewing out from underneath new cap! After cooling pulled new cap and reinstalled old one. No problems since. Two things: #1: I think I did not tighten new cap down enough as seating ring did not show that it had been seated all the way around. #2: The insides (important parts) have the same part # which is manufactured by Blau! Question: How old is your tank? Mine was leaking in same area before it was changed last year.

Paul Waterloo

Ahsai-

Thanks...that would make sense as the ride home today from the car show was very spirited on the highway and the new cap was the leak by point before. Guess I will need to sort this out before my upcoming track day on 5/18. I'm trying not to be paranoid!

But it is hard! I feel better already.

Paul

wildbilly32

P.S. leaking tank is very hard to see! Mine was cracked in back up high near seam and was not very yellow!

Paul Waterloo

I am almost sure my tank is the original tank. And probably the water pump and serpentine belt.

It's a slippery slope!

Sneaky Pete

Welcome to the club Personally I would get that tank changed. The polyrib belt is a 30 minute DIY. Now lets talk about that WP......

Warehouse33.net

My guess would be the tank too, all it takes is hair line crack. Also it's not uncommon for these to leak on most German cars.

-Jason

Ahsai

Second Pete's suggestion especially since you track your car.

Paul Waterloo

Tank on order, for now I just topped the reservoir with about 12 oz of water and put the old cap back on.

Also ordered a serpentine belt.

Warehouse33.net

If you need to order any other parts, I'm offering 10% off for Rennlisters on all parts currently on the website. Contact me if you're interested.

-Jason

rainmn

That was exactly how my tank started leaking.

I replaced my cap, due to seeing a little coolant around the edge of it. It was the old part #, and I was smelling coolant after a drive although nothing was dripping onto the floor.

Within a couple of days after the replacing the cap, the tank started leaking about the same amount as yours.

Sneaky Pete

The new cap creates a better seal and higher pressure on an old tank.....that is what brought the leak.

beetleything

That makes sense....the tank looks yellowish......