tarbender

I took my car for service the other day and the mechanic told me I should not leave the undercover on. This is the fiberglass cover directly underneath the engine covering the exhaust system. He says the cover causes the engine to heat up more which could ruin solenoids and other parts. He recommended that I leave it off. Apparently there was some memo from Porsche advising this but I guess the previous owner and dealer where it was serviced was not aware of this. Are others running without this cover?

LimeyBoy

I personally took mine off because heat management was more important than aerodynamics at 150mph+. It just made sense to me but others disagree. This topic is right up there with "what oil should I use", "why does my oil gauge not work" and "blue book values of 993's" in terms of thread counts so I recommend you make your decision after doing a search on "engine undertray". Get a coffee because it will take some reading.

MarkD

Perry, you are asking a legit question... But one that has a long, tortured history.

search on engine under tray, get a pot of coffee, sit back and enjoy

as for this thread, let the games begin

Robert993TT

Now, if you would use the 993 during winter condition what would the recommendation be then?

tarbender

Just did the search as suggested and found there is a lot of discussion on this topic. I'm leaning towards leaving it off since it doesn't really do anything except at high speeds. I drive in winter (only when roads are clear) and think I would still leave it off.

jimbo3

There is no TSB on this that I am aware of. A lot of owners in the south have removed them due to concerns about heat, but there is no documented proof one way or another. Some have said that it's purpose is part of noise abatement and some say it's purpose is aerodynamics (although factory race cars apparently raced without the tray) or a combination of the two.

I doubt that you are going to have any problem at all with engine heat in Toronto. Bottom line- do whatever you prefer as it won't make a difference either way other than maybe catching an occasional drop of oil.

geolab

there is zero Porsche memo advising removal of undertray
Any car 'engine' of any kind, is better off without an undertray
factory race cars had factory 3/1 headers, you cannot mount undertray
factory race cars clear the path for fast intervention, no undertray
mechanic is spending a lot of time on rennlist
Your 1997 lived 14 years with undertray
mine is off today

murfysflaw

Mine was off when I bought it... was off when I sold it. In fact, aside from pictures of them being used as sleds here, I've never seen one!

M Fig

I like geolab's responses...short, direct, accurate...and in one post he used the word "polyvalent"...that is a cool sounding word.

keithgreer

My former indy mechanic suggested i leave it on to catch the small oil drips. or you will go nuts and go broke fixing every little tiny leak.

chaoscreature

I just blot my garage floor every couple of days

I would probably lean towards leaving my tray ON if I ran in the snow/rain a lot. The tray may help keep a little warmth in the engine during short trips and would keep some snow/mud/dirst from getting cakes all over the underside of the engine.
My car had the tray on for the first 15 years of its life and it only recently came off but mostly because I got tired of removing/installing it and the little quarter turn fasteners are pretty shot.

911Dave

I would definitely keep it on in the winter to protect the underside of the engine from salt, mag chloride or whatever crap they thrown on the roads where you live. In the summer months, it might help to take it off but so far I have not seen evidence to support that in my case.

And add my car to the list of ones that never had it taken off up to now.

IXLR8

Although I have mine, it is only off because that is the way it came when I bought the car.

I never got around to taking actual cylinder head measurements with the cover on and off under various conditions, but I plan to...for the fun of it. I got under the engine earlier this summer and couldn't locate the threaded holes that I remember seeing for a sensor.

Cactus

Leon993

Even at high speeds the difference is negligible....and Im talking about 170 mph. Leave it off and keep it for/if you sell the car