Engine cooling and strange smell?

[RFeng]

I recently acquired a 2001 carerra conv with only 15K mi. Car runs good but I notice a couple of things that concern me.

When the car is stationary at say a red light or in heavy traffic, the temp gauge rises from about 12:00 (its normal position) to about 1:30 (I don't recall the temp values). Once the car is moving again and after a minute or so, the temp will return to normal.

After driving the car I notice a strange smell from the engine. There are no leaks, no smoke, nothing that lingers after the car has cooled down.

Any ideas on this? Is the temp gauge fluctuation normal? I'm wondering if there is a cooling fan that is not working.

Thanks

David.

[450knotOffice]

What temperatures are you indicating? My 2000 996 normally sits on the "8" of 180 and will climb up slightly past the "0" of 180 when I sit in bumper-to-bumper traffic. This past weekend, when I flogged it at the track on a 99 degree day out in the desert, it approached the 250 mark.

Porsche changed the front bumper intakes in 2001, I believe, in order to get more air into the radiators to increase cooling. The earlier cars run warmer than the later cars. For example, my wife's 2007 Cayman never gets above 175.

Also, my engine has always smelled a little funny after running for a while. If I recall correctly, when I brought this up to my mechanic, I was told that I'm probably smelling the cosmoline that the factory puts all over the engine and tranny to help prevent corrosion.

For added peace of mind, you may want to open your oil filler cap and look inside. If you see no evidence of a yellowish-white colored sludge, which would indicate that water is mixing with the oil, you should be OK.

[Aerkuld]

I don't know if this will help, but I just pulled about four handfulls of leaves out of my radiator ducts last night. When I'd done that I vacuumed out whatever else I could. It appears that those two radiator scoops make very effective garbage collecters. I have heard that its worth removing the front bumper every so often and giving the radiators a really good clean but it may be worth checking to see what you can pull out of the ducts from the front first. Just a thought. BTW, when the cooling fans cut in on the front you know it. It normally blows anything on the road surface all over the place when you're sitting still. They're normally audible from inside the car too.
Other than that I will back up 450's comments. My temperature gauge runs about the same, probably on the "8" or left hand edge of the "0" most of the time and rising to the middle or right of the "0" in traffic. That has been in 100 to 105 degree weather.

[BReyes]

Is the smell a problem. On my 996 like you I too noticed a different smell from my 3.2 (less oil and more coolant smell). I have changed the fluids, and established a baseline that i know is a good smell . I have continually cleaned the front radiators. Flushed the tranny again. Flush the coolant every oil change. The smell becomes less an issue once you know your gages are working well and the water temp needle is on the 8 for the most part, rarely on the 0 and at intense traffic temperatures holds at the 0.

It seemed like it was not long ago temps here were over 100 F every day.

[wsp8]

Heck, having just come out of a '76 911 targa, I miss the 'ole burning oil smell. So ... I was GLAD to smell something from my 996!

[DL Lawrence]

Smell- Normal. My understanding is that that smell is the tire rubber burning off of your exhaust cans, which are directly behind your rear wheels, with nothing in between. As you know, the performance tires spec'd for these cars are a very soft compound. Perfectly normal-tire dust gets on the cans, and when you're not moving, burns off.

My temp guage rides at almost 12:00 sharp, virtually all of the time. In the hotter weather that we have in Virginia in the summer, with the AC running in stop and go traffic, it would would creep up to the right edge of the "0" in 180.
A couple of weekends ago, a buddy in the local PCA helped me remove the front bumper, and clean between the radiators. There's two on each side, cooling and AC evaporator, and they are sandwiched together. You'd be amazed what gets in there. On Rennlist, there's some instructions (with photos). Do a search in the 996 forum. It's very straightforward; after having someone help me through it, I'm going clean them once per year. I've read where people have done this, and their cars ran noticeably cooler.

Hope this helps-

DL

[Chuck Jones]

Check under the coolant tank on the left...look for a white crusty substance under the tank as well as around the rim of the cap. These coolant tanks are prone to cracking under pressure forcing out coolant while your'e running, but not enough to drip on the garage floor. The caps are also prone to failing...if your cap number ends in a 0 you should upgrade it to the one that ends in a 1.

If you see the white crusty stuff, you probably need to replace the tank. There's a lot written on the subject here and on Rennlist. Do a search under "coolant tank" or "coolant smell". There's also a DIY on RennTech complete with pictures that shows you how to replace the tank yourself. I had to replace mine not too long ago. Very common failure on the 99-01 cars.